UNIVERSITY OF NORTHERN COLORADO
Greeley, Colorado
The Graduate School
THE MASSASAUGA RATTLESNAKE (SISTRURUS CATENATUS) IN COLORADO
A Thesis Submitted in Partial Fulfillment of the Requirements for the Degree of Master of Arts
Justin Peter Hobert
College of Arts and Sciences Department of Biological Sciences August, 1997
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. © 1997
JUSTIN PETER HOBERT ALL RIGHTS RESERVED
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. THESIS COMMITTEE:
*THESIS SPONSOR (Stephen P. Mackessy, PhTD.)
(William. E. Harmon, Ph.D.)
(David Chiszar, Phdj.)
DEAN OF THE GRADUATE SCHOOL
yle R. Carter, Ph.D.)
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. ABSTRACT
Hobert, Justin Peter. The massasauga rattlesnake (Sistrurus catenatus) in Colorado. Published Master of Arts Thesis, University of Northern Colorado, 1997.
The massasauga rattlesnake, Sistrurus catenatus, is currently
considered a species of special concern by the Colorado Division of
Wildlife. From. July, 1994 to October, 1996, 255 massasaugas were
captured or recovered from 11 counties in Colorado. Life history and
distribution were investigated for the massasauga in Colorado,
including an analysis of the distribution pattern and habitat
characteristics at sites of capture and recovery. Information gathered
included trends in population size and abundance, areal vegetative
analysis, seasonal/temporal activity patterns, reproduction, and prey
and predators. This study also investigated the morphological variation of the massasauga from Colorado and an evaluation of its current taxonomic status relative to S. c. edwardsi and S. c. tergeminus, the
neighboring subspecies. Morphometric characters from samples from
each group were measured and examined for diagnostic reasons. Scale counts on 18 areas of the body were examined for 268 snakes from
Colorado, 72 edwardsi from Arizona and New Mexico, and 35 tergeminus from Kansas. Distribution, habitat and life history characteristics,
iii
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. along with color and size, were also used to evaluate the taxonomic
status of the massasauga in Colorado relative to the other described
subspecies. Distribution results indicated that the population of
massasaugas in Colorado is disjunct from the neighboring populations
and is a dry, arid grassland species which occupies, short-grass/sand-
sage prairie, an increasingly uncommon habitat. The massasauga is
nocturnal in summer in Colorado and feeds mainly on lizards as
juveniles and small rodents as adults. Young are bom late summer to
early fall (one clutch size of 5). Specific scale counts showed that the
Colorado population is more closely related to the desert subspecies
(S. c. edwardsi ) than it is to the western subspecies (S. c. tergeminus).
Of the Colorado massasaugas examined, 79% had 23 scale rows at
mid-body; while S. c. edwardsi also had a frequency of 79%. Sistrurus.
c. tergeminus often had 25 (88%). Size and ground color were similar for
Colorado snakes and S. c. edwardsi, while S. c. tergeminus were much
larger and darker. The morphometric and habitat data support the
conclusion that massasaugas in Colorado should be designated as the
desert subspecies, S. c. edwardsi, not as an intergrade.
iv
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. ACKNOWLEDGMENTS
This project would have been nonexistent if not for the generosity and encouragement of the Great Outdoors Colorado program and the
Colorado Division of Wildlife, especially, Judy Sheppard, Chuck Loeffler, and Tom Nesler.
Special thanks go to my advisor, Dr. Steve Mackessy, for his
instrumental support and fortitude throughout this project, and working with me to become a better writer.
I am indebted to Dr. William Harmon for his guidance and influence
he has so constantly provided for me and others. His companionship and friendship have been a requisite.
I would also like to thank Dr. David Chiszar for assisting me through the understanding of statistics and introducing me to Dr. Hobart M. Smith who also provided valuable input and advice for this project. Lauren Livo, Geoff Hammerson and Andrew Hoiycross provided information and specimens for which I am thankful.
Thanks go to the Kansas Department of Wildlife and Parks for permission to search for snakes at Cheyenne Bottoms National Wildlife Refuge.
v
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Distinctive gratitude goes to Dr. James Fitzgerald for his vital input
and fellowship which motivated me and were critical throughout my
graduate career
Much of this project would not have been as true and enjoyable
without the companionship and hard work of Chad Montgomery, Ron
Donoho, Enoch Bergman, Scott Boback, Kevin Waldron, and Ben Hill
who literally logged thousands of miles with me looking for herps.
For Tim Hugo, Brandon Quinn, Jennifer Mauch, Robert Hill and Dr.
Jennifer Clarke I am thankful for their assistance in the field.
Many people from southeastern Colorado allowed me to search and
set traps for critters on their land and I thank them for their
willingness to work with me. The Palmer Family in Lincoln County
have been more than accommodating and neighborly and my
appreciation for them is immeasurable.
I am especially thankful and lucky to have the friendship and
encouragement of my past and present fellow graduate students who
have been an integral part of my understanding and awareness of the
fascinating field of Biology. I eminently want to thank Keri A. Fox for her companionship, moral
support, encouragement, and understanding. Her kind patience, dedication, and influence have been a boundless help throughout my
field experiences.
vi
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Finally, I wish to pass my grand gratitude to my parents for their
love and support. Everything I have, and have learned, I owe to them.
To my brothers and sisters and Smith, I dedicate this thesis.
vii
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. TABLE OF CONTENTS
CHAPTER PAGE
I. INTRODUCTION...... 1
II. DISTRIBUTION AND LIFE HISTORY OF THE MASSASAUGA IN COLORADO
Introduction...... 14
Materials and Methods ...... 16
Results...... 23
Discussion ...... 63
III. MORPHOLOGICAL VARIATION AND TAXONOMIC STATUS OF THE MASSASAUGA IN COLORADO Introduction ...... 77
Materials and Methods ...... 79 Results ...... 83
Discussion ...... 94
IV. CONCLUSION...... 98 LITERATURE CITED...... 106
APPENDICES...... 112
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. LIST OF TABLES
TABLE PAGE
1. Total search efforts (estimated) for S. catenatus by- county in Colorado (1994-1996) ...... 23 2. Species of reptiles and amphibians seen at areas where 10 or more S. catenatus were found ...... 28
3. Total number of S. catenatus for each surveyed county (1994-spring, 1997) ...... 31
4. Comparative body measurements of adult male and female S. catenatus from Colorado ...... 47
5. Number and proportion of S. catenatus captured or above ground at specific temperatures...... 49
6. Number of S. catenatus observed or collected by month (1994-1996)...... 50 7. Number of live S. catenatus captured in Colorado by time of day and by month (1994-1996) ...... 50
8. Capture and recapture data for PIT-tagged S. catenatus in Lincoln County, Colorado ...... 54 9. Prey identified in fecal material or gut contents of S. catenatus from Colorado ...... 60 10. Comparison of coloration for S. catenatus from Colorado, New Mexico and Arizona (edwardsi), and from Kansas (tergeminus)...... 85 11. Meristic and mensural comparisons of samples of S. catenatus from Colorado, Arizona and New Mexico (S. c. edwardsi) and Kansas (S. c. tergeminus)...... 88
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Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. TABLE PAGE 12. Student’s t-tests of paired means comparison of scale counts between S. catenatus from Colorado, S. c. edwardsi, and S. c. tergeminus...... 90 13. Identifications, morphometric data and locations of Sistrurus catenatus from Colorado ...... 118 14. Identifications and morphometric data of Sistrurus catenatus edwardsi (Arizona and New Mexico) ...... 143 15. Identifications and morphometric data of Sistrurus catenatus tergeminus (Kansas) ...... 151
x
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. LIST OF FIGURES
1. Dorsal views of the head for the genera Sistrurus and Crotalus...... 2
2. Sistrurus catenatus from Colorado ...... 3
3. Range of the three described subspecies of Sistrurus catenatus in North America and Mexico ...... 4
4. Distribution map illustrating new and historic localities of S. catenatus in Colorado ...... 33
5. Distribution of S. catenatus in Baca County ...... 34
6. Distribution of S. catenatus in Bent County ...... 35 7. Distribution of S. catenatus in Cheyenne County ...... 36
8. Distribution of S. catenatus in Crowley County ...... 37
9. Distribution of S. catenatus in El Paso County ...... 38
10. Distribution of S. catenatus in Kiowa County ...... 39
11. Distribution of S. catenatus in Las Animas County ...... 40 12. Distribution of S. catenatus in Lincoln County ...... 42
13. Distribution of S. catenatus in Otero County ...... 43
14. Distribution of S. catenatus in Prowers County ...... 44 15. Distribution of S. catenatus in Pueblo County ...... 45 16. Snout-vent lengths (SVL) of S. catenatus in Colorado ...... 57
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Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. FIGURE PAGE 17. Box plots depicting the percentages of rock, bare soil, litter, grasses, forbs, shrubs, cacti and total ground cover a t localities of S. catenatus in Colorado ...... 62
18. Histogram of number of dorsal scale rows at mid-body for Sistrurus catenatus from Colorado ...... 92
19. Histogram of number of dorsal scale rows at mid-body for Sistrurus catenatus edwardsi (Arizona and New Mexico) ...... 93 20. Histogram of number of dorsal scale rows at mid-body for Sistrurus catenatus tergeminus (Kansas) ...... 93
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Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. CHAPTER I
INTRODUCTION
Rattlesnakes are named for their loosely articulated interlocking
integumentary segments at the end of the tail that create a unique dry shaking buzz when the tail is vibrated. The evolution of this group of
venomous snakes, included in the family Crotalidae, is restricted to
the western hemisphere. Rattlesnakes also possess an infra-red heat sensory pit organ between the nostril and the eye. This pit organ
assists the rattlesnake when hunting prey when light is restricted.
Much of the food source of pit vipers are endotherms with a body
temperature often higher than ambient temperatures. Rattlesnakes
can detect this difference in temperatures with the aid of the pit organ,
and subsequently increase its chance of prey capture. Visual and
olfactory cues are also important for locating prey items.
Crotalus and Sistrurus are the genera of rattlesnakes recognized in North America. The genus Crotalus comprises the larger, more diverse,
often heavier-bodied rattlesnakes ranging over most of the United
States and Mexico, with a peak diversity in the southwestern United States and Sonora, Mexico. Snakes of the genus Sistrurus (3 species)
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. are designated pigmy rattlesnakes because of their generally smaller
size. Their range is restricted to the eastern, southeastern and
southcentral portions of the United States and parts of northern and
central Mexico (Conant and Collins 1992; McCoy and Minckley, 1969).
The most distinguishing characteristic of the two genera is the
presence of 9 enlarged plates on the dorsum of the head in members of the genus Sistrurus (Figure 1).
mmmm
Figure 1. Dorsal views of the head for the genera Sistrurus (left) and Crotalus (right). Note the large head plates for Sistrurus and the many head scales for Crotalus (From Klauber, 1972).
The massasauga rattlesnake, Sistrurus catenatus (Figure 2), is sometimes referred to as a “pigmy rattler,” “prairie rattlesnake”
(Atkinson and Netting, 1927) or “sand rattler” (pers. exp.). The range of the massasauga extends southwesterly from southeastern Ontario,
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 3 from from County, Lincoln Colorado. 2. Sistrurus catenatus Figure Figure
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Canada, to central Kansas, Oklahoma and Texas, southeastern
Colorado and across eastern and southern New Mexico to
southeastern Arizona (Figure 3; Wright and Wright, 1957; Hammerson,
1986; Conant and Collins, 1991; Degenhardt et al., 1996).
MASSASAUGA Sistrurus catenatu. m Desert 39 Western S3 Eastern "1
Figure 3. Range of the three described subspecies of Sistrurus catenatus in North America and Mexico with intergration zones. (Adapted from Conant and Collins, 1991).
The massasauga is a small to medium sized rattlesnake with an average adult length of 472-760 mm (Conant and Collins, 1991).
Dorsally, massasaugas are a dark gray to dark brown background color
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with a row of light or dark brown to black blotches. There are 2-3 rows
of small gray, brown or black spots on the lateral side of the body. The
belly color varies from solid black to mottled black with yellow, cream,
or white marks to completely white. The tail is ringed with alternating
dark and white colors, and a lyre-shaped marking on the top of the
head runs from the back of the eye onto the base of the neck. There
are usually 21-27 scale rows at midbody (Wright and Wright, 1957).
Slight sexual dimorphism is present, with the tail length in males
approximating 10-12% of total body length; in females it is only 7-10%
of the total length (Wright and Wright, 1957). Three subspecies have
been described.
The eastern massasauga, Sistrurus catenatus catenatus, inhabits
lowland swampy habitat below 450m elevation. The adult length ranges
from 470-760 mm with record length of 1003 mm (Conant and Collins,
1991). The general coloration is light to dark gray or gray-brown with 29
to 50 dark brown or black dorsal blotches bordered with beige or cream.
The belly is dark gray to nearly black or gray with dark gray mottling.
There are 25 scale rows at midbody (Wright and Wright, 1957). This subspecies is primarily diurnal (Johnson, 1992; Reinert, 1978).
The western massasauga, Sistrurus catenatus tergeminus, lives in
and around boggy moist areas in prairie habitat. It also has been
found in canyons and rocky outcrops (Wright and Wright, 1957; Greene
and Oliver, 1965). Average adult length is 460-660mm with a record
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. length of 883 mm (Conant and Collins, 1991). It is paler in color than
its eastern counterpart, with the dorsal blotches showing stronger
contrast with the brown ground color. There are 25 dorsal scale rows
at midbody (Wright and Wright, 1957). This snake is primarily
nocturnal during summer months (Greene and Oliver, 1965). The belly
is light with a few dark markings (Conant and Collins, 1991).
The desert massasauga, Sistrurus catenatus edwardsi, is the
smallest of the three massasaugas with a maximum length of 530mm
(Conant and Collins, 1991). It inhabits short grass prairie and
shinneiy oak woodland (Degenhardt et al., 1996). The subspecies is primarily nocturnal. Coloration is paler than S. c. tergeminus, and the
belly is nearly white with little or no pigmentation. The ground color is
typically cream. Dorsal scale rows number 23 at midbody (Conant and
Collins, 1991; Wright and Wright, 1957).
Past studies of the massasauga have investigated its natural history in Texas (Greene and Oliver, 1965), Wisconsin (Keenlyne,
1968), Missouri (Seigel, 1986), Illinois (Bushey, 1976) and Pennsylvania
(Reinert, 1978), and distribution and movements in Pennsylvania (Reinert and Kodrich, 1982; Atkinson and Netting, 1927) and Ontario,
Canada (Weatherhead and Prior, 1992). Habitat utilization in Pennsylvania (Reinert and Kodrich, 1982) and northeastern Illinois (Wright, 1941) was also investigated. Morphological variation in the S.
catenatus complex, excluding the Colorado population, has been
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investigated by Reinert (1978), Knoff and Tinkle (1961), and Gloyd
(1955; 1940). Phylogenetic analysis of the genus Sistrurus has been
evaluated morphologically (Klauber, 1972) and with molecular markers (Knight et al., 1993).
There are accounts on the species concerning reproduction and diet (e.g., Reinert, 1981; Keenlyne, 1978; Swanson, 1933; Keenlyne and
Beer, 1973a, 1973b). These studies are well-documented for the
massasauga in the east, but studies in the western part of the range are relatively old and/or are poorly documented.
Massasaugas are opportunistic predators on a wide variety of small
vertebrates, including mice, lizards, other snakes, frogs and toads
(Klauber, 1972). In the range west of Kansas, mice, lizards, centipedes and lark sparrow eggs have been documented as food for the
massasauga (Ernst and Barbour, 1989). Wright and Wright (1957) recorded crayfish, insects, fish and toads as prey for eastern
massasaugas, and lizard (Uta sp.) and centipede remains were reported
as gut contents of the massasauga in Texas (McKinney and Ballinger,
1966). Smith et. al. (1965) reported 2 Peromyscus sp. as prey for the
massasauga in Colorado. Caudal luring to attract frogs [Rana sp.) has been observed in juvenile massasaugas (Ernst and Barbour, 1989;
Schuett et. al., 1983). Predators of the massasauga include mammals such as badgers [Taxidea), skunks [Mephitis), and raccoons [Procyon); bird predators
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include hawks (Buteo), herons {Ardea), and loggerhead shrikes ( Lanius)
(Ernst, 1992). The racer, Coluber constrictor, has also been documented as a predator (Minton, 1972).
Activity periods for S. c. catenatus in Pennsylvania have been
documented by Reinert and Kodrich (1982) to be between 12 April and 4 November. Results from a study conducted by Seigel (1986) in
Missouri indicate that emergence began 9 April and annual activity
ceased by 31 October. Greene and Oliver (1965) stated that the
earliest date of a capture in Texas was 15 March for S. c. tergeminus.
There are no specific reports concerning the temporal/ seasonal activity
regarding S. c edwardsi. The massasauga in Colorado sometimes is
active during daylight hours during the spring and fall but is active at
night during the summer months (Hammerson, 1986).
Sistrurus catenatus in prairie and marshland habitat in Missouri hibernated in crayfish burrows. In the spring, they moved from the
prairie to old fields and deciduous woods and returned to the prairie in
autumn to hibernate (Seigel, 1986). In Ontario, Canada, hibernation sites of massasaugas were associated with wetlands, mixed and
coniferous forests, the same habitat associated with the summer activity (Weatherhead and Prior, 1992). Reinert (1978) reported that hibernation for S. catenatus occurred in crayfish burrows or excavated
mole tunnels that reach the water table, where the snakes remained
submerged for the duration of the winter.
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The average size of S. c. catenatus at birth as reported by Seigel
(1986), Reinert (1981), Keenlyne (1978), Wright (1941) and Swanson
(1933) is between 21.7cm-24.4cm snout to vent length (SVL). In Texas,
Greene and Oliver (1965) reported the average length at birth for S. c.
tergeminus as 22.4 cm. Currently, birth sizes for S. c. edwardsi have not been documented.
During the Pleistocene, glaciers forced S. catenatus southward into
refugia where surviving populations persisted. After the retreat of
these glaciers, massasaugas migrated northward where habitat
conditions were hospitable leading to the broad historic distribution of the massasauga. Further changes following the retreat of the glaciers
led to the expansion of the range, and subsequent subspeciation
occurred (Conant, 1978). These events resulted in continuous
grassland habitats in the eastern and southcentral United States that
provided a corridor for eastward spread, this included the Prairie
Peninsula, a long tongue of grassland and other steppe vegetation that
extended eastward from west of the Mississippi River to the Atlantic
Ocean; where S. c. catenatus occurs at present (Schmidt, 1938). Since
refugia for S. catenatus were in or near the present state of Texas
during the Pleistocene (Conant, 1978), the dispersal of S. c. tergeminus
and S. c. edwardsi north and westward may largely be due to the
availability of appropriate grassland habitats and river drainages
characteristic of the Great Plains and caused by the rainshadow effect
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of the Rocky Mountains. However, most populations of massasaugas,
particularly eastern and central, presently occur as disjunct
populations (Conant and Collins; 1991; Wright, 1941). These
fragmented populations are becoming more constricted as human
encroachment intensifies (Seigel, 1986; Pope, 1926). In the west,
populations may be more continuous because the more arid and less
disturbed habitat conditions, which are characteristic of western grasslands, have not been as intensively farmed and ranched as other
areas.
Geographically, the Colorado population appears to be disjunct from
both neighboring races, S. c. tergeminus and S. c. edwardsi, and lies
west of an area in Kansas inhabited by perhaps intergrading forms
(Maslin, 1965). The continuing advancement of human activities will ultimately further isolate massasaugas in Colorado and restrict gene
flow. In time, to protect viable populations of massasaugas in
Colorado, it may be necessary to follow other states’ management practices, and set aside land as refuges.
The Colorado massasauga has been considered an intergrade
between the western massasauga, S. c. tergeminus, and the desert massasauga, S. c. edw ardsi (Maslin, 1965). Investigation of
morphological variation has been an effective method for studying the phylogenetic relationships among other members of the family Crotalidae (Klauber, 1972) and may provide clues about the relatedness
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of the massasauga in Colorado to the three existing subspecies, S. c.
catenatus, S. c. tergeminus and S. c. edwardsi. Molecular studies ran
accompany morphological variation studies to investigate phylogenetic relationships (Knight et al., 1993) and population divergence as well (Gibbs et al., 1994). Conflicting views between Wright and Wright
(1957), Conant and Collins (1991) and Maslin (1965) as to the status of
the Colorado massasauga indicate that there is still uncertainty as to which subspecies the Colorado population is more closely related.
The population of massasaugas occurring in Colorado is centered
around Lincoln, Kiowa and Crowley counties in the southeastern part
of the state (Hammerson, 1986), although inventory efforts have
indicated the possibility of a larger range (Mackessy et al., 1996; Hobert et al., 1997). Massasaugas in Colorado inhabit a variety of habitats in the Arkansas River drainage ranging from arid open sagebrush prairie
to short-grass prairie below 5500 feet (Hammerson, 1986). Based on
only 12 available specimens, Maslin (1965) considered the Colorado
population an intergrade between S. c. tergeminus and S. c. edw ardsi , but it is clear that a more thorough analysis is required.
Adequate baseline data on the ecology and life history of the massasauga in Colorado are necessary in order to formulate appropriate management practices and to increase public awareness of
the species. Aspects of the life history of the massasauga in Colorado
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are likely to be different from those of other populations, and a
complete study of its habits, ecology and phylogeny are desirable.
The massasauga in Colorado is recognized as a species of special
concern by the Colorado Division of Wildlife, and the species (from New York to Missouri) is listed as endangered in some parts of the range
and threatened in others by the United States Fish and Wildlife Service (Ernst, 1989; Weatherhead and Prior, 1992). Eastern populations of
the massasauga persist as small relicts (Weatherhead and Prior, 1992)
and are vulnerable to complete extirpation. The status of populations
of the massasauga in Colorado is unclear, but there is a high
likelihood that populations are declining due to habitat loss and
human encroachment.
This study investigates the current population status and
distribution of S. catenatus in Colorado in order to determine habitat
characteristics and taxonomic status. The format for this study
includes two distinct but related parts. The first section concerns the
natural history and distribution of the massasauga in Colorado. The
main objectives of this study are to analyze the distribution pattern and evaluate habitat characteristics at sites of capture and recovery in southeastern Colorado. Information gathered includes trends in
population size and abundance, habitat characteristics, seasonal/temporal activity patterns, size and age of individuals, growth patterns, reproduction, and prey and predators. The second part is a
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study of the morphological variation of the massasauga in Colorado and
an evaluation of its taxonomic status relative to described subspecies.
Morphological characters of the Colorado massasaugas are measured,
and the relationship of the Colorado population and the other neighboring subspecies of the Sistrurus catenatus complex are
discussed.
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. CHAPTER H
DISTRIBUTION AND LIFE HISTORY OF THE MASSASAUGA IN COLORADO
Introduction
As a result of distribution and life history studies conducted on the
massasauga, Sistrurus catenatus, in the eastern and central parts of its
range (Weatherhead and Prior, 1992; Seigel, 1986; Reinert and Kodrich,
1982; Reinert, 1978; Keenlyne, 1968; Green and Oliver, 1965; Wright
1941), some states have listed this snake as a state threatened or
endangered species (Weatherhead and Prior, 1992; Seigel, 1986). In addition to providing natural history, habitat use, and ecological
information about the massasauga, the above studies provided critical
information about population status and viability which led to ensuing
management practices. Predictions concerning population dynamics
and trends are based on fundamental aspects such as reproduction,
mortality, prey, age classes and migration patterns. These factors are imperative for appropriate management approaches to keep populations from experiencing an irreversible decline.
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Some species are sensitive to subtle changes in their environment,
and their numbers decrease as disturbances increase. Such species
can act as indicators of overall ecosystem health, since they are affected earlier and/or by small disturbances than other species.
The life history reports of the massasauga in Colorado are limited
to one account of diet (Smith et. al., 1965), five reports concerning
distribution (Hobert, et. al., 1997; Mackessy, et. al., 1996; Pegler, 1995;
Hammerson, 1991; 1986), and one on taxonomic status (Maslin, 1965).
The paucity of reports pertaining to the biology and ecology of the
massasauga in Colorado points to the need for an investigation of
basic ecological parameters such as habitat, life history characteristics
and distribution. Furthermore, this information needs to be
investigated to ensure adequate protection of S. catenatus from extirpation in Colorado.
Sistrurus catenatus in Colorado is presently classified as an
intergrade between the western and desert subspecies, S. c. tergeminus and S. c. edw ardsi (Maslin, 1965). Geographically, the Colorado
population of massasaugas appears to be disjunct from both
neighboring races and lies west of an area in Kansas inhabited by perhaps intergrading forms (Maslin, 1965; Conant and Collins, 1991). However, based on a large data set, it is apparent that S. catenatus from
Colorado should be assigned to the subspecies edw ardsi (this topic is discussed in detail in Chapter 3). Therefore, conservation and
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management practices should be implemented based on the habitat
requirements of the desert subspecies, S. c. edwardsi. In the present
study, distribution and life history information of the massasauga in
Colorado are presented. The initial portion of this chapter addresses
the distribution by county of the massasauga in Colorado and habitat characteristics of areas where they were most common. Concluding
this chapter is a portion that addresses the life history of the
massasauga in Colorado, including biology and ecological behavior.
Materials and Methods
Study Area
Research was conducted in 13 counties of southeastern Colorado, a
vast area essentially south of Interstate 70 and east of Interstate 25.
In this region of the state, land is commonly owned in large parcels
and is sparsely populated. It is not uncommon for individuals to own
60 km2 (23 mi2) and to utilize up to 260 km2 (100 mi2) for use for
agricultural purposes. Although the study area is very large, survey efforts were concentrated within and around the fringes of the current
documented range and at documented outlier localities (Hammerson,
1986). The natural vegetation of eastern Colorado is somewhat variable,
particularly given the relatively low elevational gradient. The most
common vegetative type in eastern Colorado is short-grass prairie
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which gives the landscape an appearance of uniformity. The prairie in Colorado is drought-tolerant short-grass prairie in which the dominant
species are blue gramma ( Chondrosum gracilis) and buffalo grass
[Buchloe dactyloid.es). Plant communities with an affinity for sandy
soils (sand-sage prairie) include sand sagebrush (Artemesia filifolia) and
a variety of grasses dominated by blue gramma or sand bluestem
[Andropogon hallii). Pinon/juniper woodland make up most of the rest of
the dominant vegetation types and are characteristics of the Mesa de
Maya, Black Mesa and Raton Mesa regions to the south (Madole, 1995).
Plant names used throughout this thesis are from Weber (1976).
The soils of the known range of the massasauga in Colorado are
classified into two major groups: Aridisols and Entisols. Aridisols and Entisols are characterized as warm and dry soils that are low in organic
matter and moist less than 3 consecutive months. Aridisols are
generally referred to as gently sloping and Entisols are usually
associated with moderately sloping regions (USDI, 1967).
The Arkansas River drainage bisects the region and flows in a west
to east direction. Lowland riparian ecosystems are present along the tributaries of the Arkansas River including Big Sandy Creek and the Purgatoire River, the two main tributaries of the Arkansas River east of
the Rocky Mountains and west of the Kansas/Colorado state borders.
Much of the land in southeastern Colorado is utilized for agriculture including grazing and irrigated and dryland farming. Some
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land is set aside for state wildlife areas and recreational use. There
are federal and state agencies that control areas for ground testing and military purposes.
Climate within the southeastern region of Colorado is semiarid. Approximately 70%-80% of the precipitation occurs April through
August, mainly from thunderstorms (Madole, 1994). The summers are
long and hot, with an average temperature between May and September
of 18.3° C (McGinnies et. al., 1991). During most years, the maximum
temperature reaches or exceeds 38° C on some days at a weather
station at Karval, located in south-central Lincoln County. Average
annual precipitation at this station is 33.4cm (NOAA, 1995).
Initial survey efforts were performed at areas documented as
historic localities. Extensive surveys of the study area were performed
outside of the known range to make note of any suitable habitat for the
massasauga particularly toward the southeast. Survey efforts were
concentrated at more specific locations as occurrence and encounters
increased. One area in Lincoln County was exceptionally productive, and much of the data reported in this study came from this area; S.
catenatus was the most common reptile in this region and the area was extensively investigated. A description of 8 areas where significant
numbers of S. catenatus were captured or recovered, including habitat
characteristics, dominant vegetation, information on land use,
elevation and land form characteristics, is included below.
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The specific locations of collection sites for S. catenatus are not
presented in this thesis because of its status as a species of special
concern and out of respect for the local landowners whose lands
provide the snakes habitat. Inquiries about the locations and study sites should be made to the Colorado Division of Wildlife. Distribution
The primary method for locating massasaugas consisted of road surveys (Greene and Oliver, 1965). In the summer months, many
snake species are encountered at night along country roads. Driving
roads at times of peak activity during the summer months is the most effective means for recovering this species (Knoff and Tinkle, 1961).
Surveys were conducted during the spring, summer and fall months
between 15 July, 1994 and 18 October, 1996, when snakes were
expected to be out of hibernation. Localities for snakes found on roads
were recorded to the nearest 0.1 odometer mile from an intersection or
other permanent landmark. Mileage was converted to kilometers.
Suitable habitat was surveyed on foot. A limited number of drift fences
were used (Clawson, 1984) in an attempt to capture animals away from
roads. Snakes were captured by Furmont snake hooks or by small clamp sticks and housed in plastic containers until processed; snake bags were used to carry animals to the vehicle. Snakes were housed in
plastic containers and placed in the shade when surveys lasted more than 1 day. Snakes were provided with water and a separate container
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when housed in the animal facility until processed. Sites of collection
of live animals and recovery of road-killed animals were mapped on 15
and 7.5 minute maps and transferred to electronically scanned SCS maps (1965) in order to create the range maps.
Life History Characteristics
The distribution of collected S. catenatus was mapped and compared
to published accounts. Specific locations were recorded to range, township, section and quarter section (see appendix I) and then were
plotted and mapped for each county on 15 minute maps. Temporal
activity was summarized by month for live snakes. Occurrences of S.
catenatus by county and month were recorded and combined for live and dead snakes.
Air temperatures at one meter were recorded or measured from
public radio addresses or with a thermometer when S. catenatus were
captured. Temperatures were also calculated from data provided by
NOAA (1994-1996). Temperature data for road-killed snakes (DOR) was not measured unless the snake was freshly killed as indicated by
bleeding or muscle movement. Daily local temperature data were also
obtained from the closest National Oceanic Atmospheric Administration (NOAA) weather station in the study area. StowAway Temperature Data Loggers were installed (3) in mid-July, 1996 at
locations of relative high density of S. catenatus.
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Biosonic and Avid passive integrative transponder (PIT) tags were
injected subcutaneously (-2/3 posteriorly on the right lateral side) into
each live S. catenatus captured. Twelve neonatal snakes were too small
to PIT tag. PIT tags provided an individual identification number for each snake.
An electronic balance was used to weigh snakes to the nearest O.lg.
Tail length (TL) and snout-vent length (SVL) were measured. Sex was
determined by the tail length to total length ratio or by the presence of
hemipenes in males. Body measurements were made using a meter
stick. Shedding frequency was determined by painting the basal rattle
with navy blue automobile paint and counting added segments between
individual snake recaptures. Time of birth was investigated by
observing post-parturition females and recording the time of year and
frequency of encounters with young of the year snakes.
Diet was determined by dissecting the stomachs of road-killed
snakes, examining fecal material of captured snakes or observing feeding episodes in the field. Fecal samples of wild-caught snakes
were obtained if snakes defecated during processing at the animal
facility. Fecal samples were examined for hairs, scales and other matter using culture dishes, forceps and a Nikon SMZ-2T stereoscopic
microscope. Hair strands found in fecal samples were mounted on slides to aid in their identification. Rodent hairs from museum
specimens of species known to occur in the study area were mounted
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on slides and compared with the unknown hair slides (Keenlyne and
Beer, 1973). From personal observation, there was considerable rodent
activity along roads where massasaugas were found as well as in the
undisturbed areas. Observations of potential predators were noted. Habitat Analysis
A modified version of the line intercept method described by Cox
(1996) was used to sample areal vegetation at specific localities of S.
catenatus. In recording line-intercept data, plants that were touched by
the transect line or that lie below or above were classified and recorded
as one of the following: annual grass, perennial grass, forb, shrub or
cactus. Rock, bare ground or litter were recorded at points if no plants
touched the line. Transect lines were 30m in length with points of
recording at 0.33m intervals creating 91 points per transect.
Frequencies of occurrence were calculated and grassland conditions
and areal coverage were compared between sites where snakes were
collected using a box plot (Glass and Hopkins, 1996). The line
intercept technique is effective for low growing vegetation.. Since greater than 95% of encounters with massasaugas occurred
on roads, line transects were constructed beyond the fence line along the road where homogenous habitat began. This was just inside the fence line or property line. If a massasauga was found in the field,
then a transect line midpoint (15m) was placed at the exact location of capture and the above methods were utilized.
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Results Distribution
Road surveys comprised an estimated total of 195,600 km traveled, most of which were traveled in Baca, Bent, Crowley, Kiowa, Las
Animas, Lincoln, Otero, and Prowers counties. These surveys resulted
in frequent encounters with massasaugas. Table 1 represents road
kilometers traveled for each county. Distances are estimated. Surrounding counties were surveyed extensively, but resulted in
locating additional massasaugas less frequently. Searching suitable
habitat by foot in some counties accounted for relatively more survey
time and less survey distance there than for other counties.
Table 1. Total search efforts (estimated) for S. catenatus by county in Colorado (1994-1996).
County Survey time (hrs) % Total Survey distance (km) % Total Baca 376 13 19,000 10 Bent 208 7 12,700 6 Cheyenne 112 4 9,100 5 Crowley 208 7 12,900 7 Elbert 56 2 4,500 2 El Paso 88 3 6,400 3 Kiowa 304 10 24,500 13 Kit Carson 8 0.3 700 0.3 Las Animas 176 6 11,600 6 Lincoln 800 27 53,300 27 Otero 320 11 19,200 10 Prowers 280 9 20,300 10 Pueblo 16 0.7 1,400 0.7 Total: 2952 100 195,600 100
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The following habitat descriptions are for areas where more than 10
S. catenatus have been found within a 15 km radius.
Area I.—Private property located north and south along State
Highway 94, approximately 5 km east of the intersection with State Highway 71 at an elevation of 1579 m. This area, comprised mainly of
sections of CRP (Conservation Reserve Program) vegetation including
blue-stem (Andropogon sp. and Schizachyrium sp.), immediately
surrounds a 4 hectare shallow, permanent body of water. Blue gramma
(Chondrosum gracilis), buffalo grass (Buchloe dactyloides), sand
sagebrush [Artemesia filifolia) and yucca (Yucca glauca) are the major
flora present surrounding the sections of CRP.
Area 2 .—Intersection of State Highway 94 and Lincoln County Road
32. This intersection at an elevation of 1499 m is surrounded by
private property. Dominant vegetation are Buchloe dactyloides and
Chondrosum gracilis, interspersed are clumps of Yucca glauca and prickly
pear cactus (Opuntia polyacantha). North Rush Creek is 1 km to the
west. The landscape has knolls of fine sand merging with hard packed
arid loamy soil. Area 3.—Hugo State Wildlife Area (SWA) is on Kinney Hill at the
western side of Buffalo Basin at an elevation of 1540 m. Lincoln County Roads 2G and 36 intersect at the wildlife area which is leased
for grazing by local cattle ranchers. The wildlife area consists of the same vegetation characteristics as the surrounding vicinity. East of
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the SWA is Buffalo Basin; Buchloe dactyloides and Chondrosum gracilis constitute the major vegetation with Opuntia polyacantha, Yucca glauca
and Artemesia filifolia in sporadic clumps. Immediately northwest of the
SWA, wheat is grown and harvested in the fall every other year (P. Forestall, pers. com.) and to the southwest is short-grass prairie.
Area 4-Intersection of Hwy 94 and Lincoln County Road 43. This
area, at 1460 m altitude, yielded more than half of the total number of
S. catenatus examined during this study. This private land is used for
grazing cattle throughout the year with stock rotated frequently from
pasture to pasture (J. Palmer, pers. comm.). Chondrosum gracilis and Buchloe dactyloides are the grasses. The landscape consists of
relatively young sand hills with intermittent seasonal streams. There
are no permanent bodies of water within a 20 mi radius except for
holding tanks and small man-made reservoirs. The water table has
dropped considerably over the last 100 year period (J. Palmer, pers.
comm.).
Area 5.—Hwy 59 north of Kit Carson, Cheyenne County. This paved
road is frequented by heavy truck traffic and is designated as a route
for hazardous cargo. (Cheyenne County is the leading producer of petroleum products per capita in the state; E. Bergman, pers. comm.). The surrounding landscape is at an altitude of 1360 m and is characterized as gently rolling hills with recurrent streams. Dominant
vegetation is Chondrosum gracilis and Buchloe dactyloides. Five miles
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east of this region is the eastern-most extension of the range of S.
catenatus in Colorado. Much of eastern Cheyenne County has been
cultivated (mainly for wheat) and most of the short-grass prairie has
been removed. Consequently, this region is probably the main area in
Cheyenne County (and probably Colorado) north of Big Sandy Creek where a substantial population of S. catenatus occurs.
Area 6.—Intersection of Hwy 71 and Lincoln County Road M. This
area is at an elevation of 1540 m and slopes into Horse Creek Basin.
Chondrosum gracilis and Buchloe dactyloides occupy most of the site and
Yucca glauca and Opuntia polyacantha are scattered sporadically. The land is used mainly for cattle grazing, with 1 section to the east
utilized for cultivating wheat.
Area 7.—Intersection of Kiowa County Roads T and 2. This area in
the Mustang Creek Basin is at an elevation of 1377 m. The soil is
loamy with the characteristic short grass prairie species of Chondrosum
gracilis, Buchloe dactyloides and Opuntia polyacantha. This vast area of short-grass prairie is utilized for cattle ranching. Some isolated
sections are tilled for wheat and are unsuitable habitat for S. catenatus.
Area S.—Intersection of Kiowa, Crowley and Otero counties.
Characterized by heavily grazed, native short-grass prairie of
Chondrosum gracilis and Buchloe dactyloides, this is a relatively uniform
landscape at an elevation of 1387 m. The Topeka-Santa Fe Railroad runs in an east-west direction. Hwy 96 has a moderate amount of
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traffic and parallels the railroad tracks. This is a significant historic locality for S. catenatus (Hammerson, 1986).
Table 2 shows reptile and amphibian associations with S. catenatus
at the sites described above. Note the diversity of herpetofauna at Area 4. Many of these species were not active or found during times of
massasauga activity. Most reptiles associated with the massasauga
appeared tolerant of slightly higher temperatures than recorded during massasauga activity periods.
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Table 2. Species of reptiles and amphibians seen at areas where 10 or more S. catenatus were found. (See area descriptions). Animal names are from Conant & Collins (1991).
Species Area Area Area Area Area Area Area Area 1 2 3 4 5 6 7 8 Lacertilia Cnemidophoms sexlineatus X X XXX Eumeces obsoletus XX X Holbrookia maculata XX X X X X XX Phrynosoma XXX XX X douglassd Sceloporus undulatusXXX XX X Serpentes Arizona elegans X X Coluber constrictor XXXXX X X X Crotalus uiridis X X XXX X XX Heterodon nasicus XXXXX X X X Lampropeltis tnangulum X XX X Masticophis flagellum XX X XX Pituophis melanoleucus X XX X X X XX Tantilla nigriceps X Thamnophis radix XX X XXXX X Tropidodonion Imeatum XX Testudines Chelydra serpentina XX X Chrysemys picta XX X XXX Terrepene omata XX X XX X X X Caudata Ambystoma ttgrinwn X XX X Anura Bufo cognatus XXX XX XX X Bufo woodhousei XXX XX X X X Spea bombifrons X XX XX X X X Spea multiplicatus X X Rana blairi XXX XX X X X Rana catesbeiana XXX X X X X Rana pipiens XX XX X X Pseudacris triseriata XX X X X X
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Other notable areas where S. catenatus have been encountered in lesser numbers include:
Hwy 96 near Chivington, Kiowa County.—This habitat is dominated by
Artemesia filifolia, Chondrosum gracilis and Buchloe dactyloides in native
condition. Big Sandy Creek is the major waterway. This is the location
where 2 massasaugas were recovered, representing an eastern range extension.
Two Buttes State Wildlife Area, Baca/Prowers County.—This location is
one mile south of the intersection of Highway 287 and Prowers County
Road B.5 where Two Butte Creek runs parallel with the county line.
Chondrosum gracilis and Buchloe dactyloides habitat is found in a
northwesterly direction. Yucca glauca and Opuntia polyacantha is interspersed in clumps. The SWA east is mainly short grass prairie
with forested areas around the reservoir. Land to the south of the
SWA is used mainly for farming. Initially, this SWA was used as a
water skiing and fishing resort. This locality is where the Prowers
County distibutional record for S. catenatus was recovered.
Near Medford Springs Between Mud Creek and West Mud Creek, Bent County.-This habitat, short grass prairie dominated by Chondrosum
gracilis, Buchloe dactyloides, and Yucca glauca in clumps, surrounds the
intersection of Bent County Roads L and 28. This grassland appears continuous with the Two Buttes area to the southeast.
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Crowley County.-Only three roads bisect the county in a north-
south direction and one in an east-west direction. Surveying in a
vehicle was not an effective method for sampling most areas.
Surveying on foot was not time-efficient and access to private property
was limited to short forays beyond boundary fences that lined the road.
Short-grass prairie and sand sage habitat constitute most of the floral
composition in this county. Crowley County is a relatively small
county with landscape characteristics that should provide habitat for
numerous amphibian and reptile species that have yet to be discovered
there (Livo et al., 1996; H. Smith, pers. comm.).
County Distributions.-County distributions provide an increased
understanding of the habitat association and distribution of an
organism in that county. Managers can look at how lands are used at
specific areas of the county and determine if the utilization of that land
is promoting the continued existence of the organisms of concern.
They can also make recommendations to others about the habitat
where the organisms exist. County distribution information provides
patterns of abundance which can help managers decide if that area is needed as a parcel for conservation. During this study, 256 S. catenatus were captured or recovered,
which added a new distributional record for Prowers County and a second voucher specimen to support the recent El Paso County
distributional record (Pegler et al., 1995; Mackessy et al., 1996). My
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study extended the eastern range of S. catenatus in Cheyenne and
Kiowa Counties and the southeastern range in Bent County. One
snake was recently (May, 1997) recovered from northwestern Baca
County, extending the southeastern-most region of the range. One snake was recovered on Boone Road in Pueblo County but the
specimen has been lost and another was found on the Pueblo/Crowley
County line road; these occurrences support the hypothesis that the
western border of the range is in eastern Pueblo County. The
northern-most locality of a massasauga during this survey was 2.2 km
south of Hugo, Lincoln County. Table 3 shows numbers of snakes captured for each county surveyed; DOR indicates the snake was found
“dead on road”.
Table 3. Total number of S. catenatus for each surveyed county (1994- 1996; Two additional specimens, one each for Otero and Baca Counties, were found spring, 1997).
County Number captured live Number recovered (DOR) Total Lincoln 149 59 208 Kiowa 3 21 24 Cheyenne 2 8 10 Crowley 1 6 7 Otero 0 2 2 Pueblo 0 2 (1 specimen lost) 2 Baca 0 1 1 Bent 0 1 1 El Paso 0 1 1 Prowers 0 1 1 Elbert 0 0 0 Kit Carson 0 0 0 Las Animas 0 0 0 Total: 155 102 257
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Every massasauga captured or recovered during this investigation is considered as a new locality. Literature records concerning the
distribution of the massasauga in Colorado before this study are
referred to as historic. Many localities reported in this study support historic localities and thus can be referred to as either. The historic
accounts were compiled by Hammerson in 1982 and reprinted in 1986
without any additions. There are published additions since 1986 and prior to this study, and these are also considered historic localities.
In the past, Hammerson (1986) considered a Baca county account
as doubtful while Gloyd (1955) and Maslin (1965) accepted it as a
confirmed locality record. I consider the Baca county historic locality
as valid based on the recovery of a road-killed specimen 50 m north of
the Baca county line in Prowers county and the recent recovery of a
massasauga (UNC-MNH #516) in the county itself. The Baca County
specimen, originally thought to be lost, is located in the Chicago
Natural History Museum catalogued as CNHM 2468 (Gloyd, 1955). A Las Animas county specimen of S. catenatus was found on October 1,
1988 and is included in the literature (Hammerson, 1991). The
documented occurrence of S. catenatus in eleven counties of Colorado implies that populations are more widespread than previously believed. Figure 4 illustrates all confirmed range extensions and county
distributional accounts for S. catenatus in Colorado. Plots denoted as new localities indicate S. catenatus found during this study period and
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the confirmation of the past anecdotal account from Baca County.
Plots denoted as historic were published by Hammerson (1986; 1991).
LINCOLN KIT CARSON
,^ . 1 KIOWA
j ^B E N T pr o v
LAS ANIMAS
Figure 4. Distribution map illustrating new and historic localities of S. catenatus in Colorado. Multiple records in close proximity are represented by a single symbol.
Figures 5 through 14 show each surveyed county with a more detailed illustration of the range extensions and population distributions. Each county map shows points of orientation, such as
drainages and man-made water reservoirs or canals. County maps are in alphabetical order and are modified from USDA (1965).
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I W J ' Two Buttes Reservoir State Wildlife Area
Figure 5. Distribution of S. catenatus in Baca County. Square denotes locality for specimen UNC-MNH#516.
Baca County was surveyed extensively resulting in the recovery of 1
DOR massasauga (Figure 5). This county appears to represent the
southeastern fringe of the range of the massasauga in Colorado. There are intermittent canyons in western Baca County containing a diverse herpetofauna. Short-grass prairie is characteristic of the native flora
to the east. Parcels in southeastern Baca County are managed portions of the Commanche National Grassland; this area holds a population of the state threatened lesser prairie chicken (Tympanuchus
pallidicinctus). More survey effort is needed in this area.
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MudJ Creek
Figure 6. Locality symbols of S. catenates in Bent County. Distance between localities is -65 km. Circle denotes literature record and square for specimen UNC-MNH#212.
More data is needed to get a better understanding of the distribution of the massasauga in Bent county. The southern half and
northern one-quarter is in a relatively natural condition. Many natural
waterways still occur but there is an increase in man-made reservoirs used for agricultural purposes. The northern half is fragmented and heavily utilized as cropland and for various human activities. Figure 6
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suggests a large gap exists between populations or a constriction of
the historic range has occurred. There is also the possibility of the Arkansas River drainage providing a partial barrier to dispersal.
Eastern Cheyenne County is almost completely tilled or has been in
the recent past and shows little recovery of natural vegetation. The
pattern of occurrence of the massasauga in this county reflects this
disturbance. Western Cheyenne County has suitable habitat but human encroachment is evident in areas where massasaugas have
been recovered (Figure 7). Evidence from this study of massasauga
distribution (including recovery of a specimen from western Cheyenne
County) indicates that there are viable populations of the massasauga in the vicinity of the Big Sandy Creek drainage between the historic locations in Cheyenne County.
Big Sandy Creek’ sh Creek
Figure 7. Distribution of S. catenatus in Cheyenne County. Circles denote literature records and squares new localities. Multiple records in close proximity are represented by a single symbol.
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Horse Creek,
Colorado Canal
Lake Meredith4
Figure 8. Distribution of S. catenatus in Crowley county. Circles denote literature records and squares for new localities. Multiple records in close proximity are represented by a single symbol.
Recent collecting extends the northern range of S. catenatus in
Crowley County (Figure 8) by about 30 km. The known range now
extends further to the west from the principally southeastern records.
Much of Crowley County consists of rangeland, except along the
Arkansas River where the area is primarily cropland. Vegetation in Crowley County is still largely grasslands and sand sage habitat with sandy, unstable soils that restrict farming.
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Pond Creek'
Figure 9. Distribution of S. catenatus in El Paso County. Circle denotes historic site and square for the new locality of specimen UNC- MNH#100.
On 22 May, 1995, one massasauga was collected in El Paso County
(Figure 9), over 7 years since the last record (Pegler et. al., 1995). The
massasauga is probably restricted to the southeastern quadrant of the county because of urbanization and heavy agriculture (Colorado Springs, sod farms and intense grazing) which has likely resulted in the extirpation of the massasauga from previously suitable habitat.
The massasauga is likely restricted by topography in the western 1/3 of the county and by more habitat fragmentation in the northeast.
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Figure 10. Distribution of S. catenatus in Kiowa County. Circles denote literature records and squares for new localities. Multiple records in close proximity are represented by a single symbol.
Kiowa County (Figure 10) is fragmented into large parcels of
grassland interspersed with more intensive agriculture that is largely
for wheat and com production. The area between the new eastern
localities along Big Sandy Creek and the western populations near the
border is used for agriculture and this has resulted in a disjunct
occurrence of the massasauga in the county. The area around the new
eastern localities near Big Sandy Creek consists primarily of sand
sagebrush habitat. The scarcity of intense agriculture in some areas likely favors massasauga abundance.
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iver
Figure 11. Distribution of S. catenatus in Las Animas County. Circle denotes locality of lone voucher specimen from the county.
I did not find the massasauga in Las Animas County (Figure 11). The paucity of reports of occurrence of the massasauga in Las Animas
County indicates that there is a need for further study. This is a very
large county, much of it with poor access, and many areas need much more inventory effort. Hammerson (1991) published the only county
record, a specimen from near Model. The Commanche National
Grassland has habitat that appears suitable for massasaugas. The
Black Mesa and Raton Mesa regions along the southern border are
mostly in pifion/juniper woodland, uncharacteristic of the massasauga
habitat I have observed. Two-hundred and eight snakes were found in Lincoln County (Figure
12), the most from any county during this study. These high numbers of snakes were a result of extensive survey work, expansive areas of
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grassland habitat suitable for the massasauga, and the accessibility of snakes following emergence and ju st prior to ingression.
The habitat south of Big Sandy Creek in this county was generally
native short-grass prairie, with sand sage habitat immediately south of
the Big Sandy Creek. There were many small riparian communities
along the intermittent creeks associated with Big Sandy Creek, Rush Creek and Horse Creek. In much of Lincoln County, native species of
grasses have persisted. Relatively well preserved grass communities
still exist where grazing has been minimal, although the abundance of
massasaugas was relatively low at areas where heavily grazed prairie
occurred. Extensive farming was absent in the county except in small
sections usually located in the immediate vicinity of townships. Wheat was grown at these areas.
The large number of snakes found in Lincoln County was primarily
attributed to local ranching practices. Many ranchers own large parcels
of land for grazing, allowing frequent rotations of cattle that support
high quality native vegetation for grazing. This practice helps retain the habitat in nearly native condition, beneficial for massasauga
populations. Farming in this county is restricted because soil types
are inappropriate (sandy, acidic) to support large tracts of wheat and com. Large parcels of intact prairie were frequent where massasaugas
were abundant in Lincoln County. Massasauga density was highest in Lincoln County than in any other county surveyed.
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iRush Creek*
Figure 12. Distribution of S. catenatus in Lincoln County. Circles denote literature records and squares new localities. Multiple records in close proximity are represented by a single symbol.
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Apishapa River®
Purgatoire, River
Figure 13. Distribution of S. catenatus in Otero County. Circles represent literature records and squares, new localities.
Records of the massasauga in Otero County (Figure 13) are rare, but I have observed habitat that is suitable for the massasauga and where
it should be more common. Survey efforts were concentrated in the north and east and resulted in the recovery of 2 specimens, from State
Highway 109 and from Rourke Road south of La Junta. There are also
specimens for the southwestern and the north central localities. G. Hammerson and L. Livo (pers. comm.) have observed snakes from the
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southwestern area (same location) and the east central part of Otero County on State Highway 109.
Arkansas River
North Butte Creek
Figure 14. Distribution of S. catenatus in Prowers County. Square represents the new distributional record (UNC-MNH#212).
Prowers County (Figure 14) was surveyed extensively for the presence of the massasauga. Only one massasauga, a DOR specimen which was badly dried out, was found. No morphometric data were
possible from this snake. Prowers County is mainly short-grass prairie, but much of it has been tilled in the north and east. The
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Arkansas River provides residents irrigation water for farming, similar
to the situation in Bent County, but grassland fragmentation is more
extensive in Prowers County. The massasauga in Prowers County
appears to be rare, and further investigation of this area is necessary. Intensive efforts should continue at the location of the new locality and in other areas of habitat suitable for the massasauga. 7
Figure 15. Distribution of S. catenatus in Pueblo County. Circle represents literature record and squares new localities.
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The occurrence of the massasauga in Pueblo County is similar to
the distribution in El Paso County in that records are limited to the
northeast comer of the county. Survey efforts were not made in
western areas of the county. More survey effort is needed to determine
the occurrence of the massasauga in this county. In the eastern half
of this county there are areas suitable for the massasauga but these
are disappearing, especially in sections immediately east of the city of
Pueblo (Walker et. al., 1996). The western half is severely impacted by
human activity in areas once suitable for massasaugas.
Life History Characteristics
Body size and sexual dimorphism.—Table 4 shows diagnostic
characteristics for adult male and female massasaugas in Colorado.
Results from a student’s T-test of means of snout-vent length (SVL) for
females versus males do not show significant differences (p>0.05;
DF=75). Seigel (1986) reported no significant differences between adult
male and female SVL from Missouri. There are significant sexual differences of means for tail length (TL) (p<0.05), relative tail length
(RTL=TL/SVL), and body weight. Mean RTL for males is 0.123 (n=125) compared with 0.092 in females (n=87). Body mass, SVL and TL were
not recorded for some DOR specimens (-25) due to poor condition.
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Table 4. Comparative body measurements of adult male and female S. catenatus from Colorado. Mean and SD are shown above the range and sample number (N).
Sex Snout-vent Tail length Relative Tail bands Body ______length (mm) (mm) tail length weight (g) Males 355.1±49.1 43.5±7.1 0.123±0.01 7.7±1.3 42.1±18.6 259-485 27-62 0.095-0.158 5-11 16-116 N-127 N=128 N=125 N=130 N=68
Females 352.6±32.5 32.4±3.3 0.092±0.009 6.3±1.1 32.8±8.1 270-453 24-44 0.075-0.127 4-9 15-60 ______N =87 ______N =87 ______N = 87 ______N =88 N = 67
Activity Pattems-Massasaugas were active in Colorado from mid-
April until late October. The earliest date a massasauga was found was 13 April (1996); both were DOR within 100 m of each other. Later
that day, snow accumulation was 5 cm (30 mi east, at Karval) and 19
cm (50 mi southeast, at Haswell). Temperatures did not drop below
freezing and reached a high of 27 °C for 6 consecutive days prior to 13
April but did drop below 0 °C 9 out of the next 16 days (NOAA, 1996).
The latest fall date a massasauga was observed was 15 October,
1995, although a Plains garter snake (Thamnophis radix) and Bullsnake
(Pituophis melanoleucus) were observed on 21 October on the study area
that same year. For the last 10 days of October, temperatures fell
below 0 °C every evening at Karval (NOAA, 1995). By the third week of
October of that year annual migrations had ceased. Massasaugas were
active for up to 185 days that year, but this may vary widely from year
to year.
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Massasauga activity periods were highest when ambient air
temperatures that ranged between 14 °C and 30 °C (Table 5). The
average temperature at the time live snakes were found was 22.1°C
(SD= 2.5). Daily temperature fluctuations during summer months
provided snakes an interval of optimal temperatures for crepuscular or nocturnal movement when air temperatures for most summer days
were between 20 °C and 26 °C. Eighty percent (126/157) of massasauga
captures were made within this temperature interval.
During daylight hours (06:00-20:30) during spring and fall, 41.5%
(62/164) of massasaugas were captured. Temperatures during this time period were between 20 °C and 26 °C. Temperatures when
massasaugas were active were relatively consistent throughout the
season regardless of time of year. This infers the activity patterns are
temperature dependent and not dependent on the time of day. The
paucity of data for temperatures during actual emergence from
hibernation leaves uncertainty as to whether a biological clock dictates
when a snake emerges or if the snakes depend entirely on ambient
temperature as an indicator. Some snakes were found with fatal
injuries (N=9) but were considered AOR if there was muscle movement and or bleeding. Air temperatures were not recorded for 7 AOR snakes.
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Table 5. Number and proportion of live S. catenatus captured or above ground at specific temperatures.
Temperature °C Number of snakes Percent
14-16 2 1.3 16-18 4 2.5
18-20 7 4.5
20-22 63 40.1
22-24 35 22.3
24-26 28 17.8
26-28 17 10.8
28-30 1 0.6 Total: 157 100
Table 6 shows seasonal activity for massasaugas in Colorado. The
table includes information from 13 specimens from the University of
Colorado Museum. Massasaugas were found most commonly in
September (106), October (53) and April (38) and were least common
from May through August. Massasaugas were diurnal in early spring
and fall, and extensive night driving during April and October yielded no
snakes. Sixty-seven massasaugas were collected between 1 May-30
August, and all were found after dark.
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Table 6. Number of S. catenatus observed or collected by month (1994- 1996). Data are from specimens found during this study (N=254) and preserved specimens (N=13) at the University of Colorado Museum.
April May June July Aug. Sept. Oct.
Total found (DOR&AOR) 38 10 12 20 27 106 54 Percent of Occurrences ______14.3 3.8 4.5 7.5 10.2 39.8 19.9
Daily activity varied monthly (Table 7). Massasaugas in Colorado
are primarily nocturnal. The last spring day a massasauga was found'
during daylight hours was 26 April (1996) at 16:00. Snakes were not
active during the daylight hours between 26 April and 3 September. September 26 (1995) was the next date that a substantial number of
active (moving) massasaugas were encountered during daytime hours.
Table 7. Number of live S. catenatus captured by time of day per month in Colorado (1994-1996).
Hours April May June July Aug. Sept. Oct.
07:00-11:00 9 0 0 0 0 5 5
11:01-15:00 10 0 0 0 0 12 21
15:01-19:00 4 1 0 1 1 7 8 19:01-23:00 1 1 1 8 12 56 0
23:00-03:00 0 0 0 0 1 0 0
Total 24 2 1 9 14 80 ______34
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Between 23 April and 26 April 1996, a total of 32 massasaugas were
discovered DOR (6) or migrating east (N=24) across a 5 km section of a
dirt road during daylight hours (10:00-19:00). The only other encounter
with live massasaugas in the daytime was in June when 2 snakes were found about 10 m apart under 2 boards.
Seasonal variation in habitat use is difficult to ascertain without
the aid of radio-telemetiy (Reinert, 1993). Surface vegetation and
canopy cover varied little at all of the locations where massasaugas
were recovered (See Figure 17). In Colorado, it appears that there are
areas where massasaugas migrate from hard clay, loamy soils to loose sandy substrate for the summer and reverse this trend in the fall.
Population Parameters
Capture/recapture-A total of 143 massasaugas were pit-tagged for
identification. Eight snakes were recaptured; the longest interval
between captures was 343 days and the shortest interval was 11 days
(Table 8; since the time of this writing, 3 more have been recaptured).
Three of the recaptured snakes had lost weight. One adult male (field # A-1258) captured and pit-tagged 26 September, 1995, was recaptured
on 26 April, 1996. This interval (211 days) generally coincides with my
observed dates for retreat to and emergence from hibernation. The
snake weighed 61.8g when initially captured and, approximately 2
weeks after emergence at the time of recapture, it weighed 53.6g, a loss
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of 13.3% of the initial body weight (see Table 8). This figure helps estimate the energy costs of hibernation.
Two females, A-1261 and A-1366, also lost weight, and based on
mass and muscle tone, both were likely postparturent. The initial body
weight for A-1261 (26 September, 1995) was 42.2 g, and 343 days later
(4 September, 1996) it weighed 40.6g, a loss of 1.6g. The interval
between captures included a period of hibernation and the snake was
at post-parturition at the recapture date. The initial body weight for A-
1366 was 36.8g (24 April, 1996); 163 days later (5 October, 1996) it
weighed 36g, a loss of 0.8g. This interval did not include a hibernating period but the snake was at post-parturition at the recapture date. In
addition to the energetic demands of reproduction, gestating females
probably become reclusive and avoid eating in the latter part of
gestation and consequently, lose body weight. Because the snake was
recaptured late (5 October, 1996), she had had time to gain weight after
giving birth and before her recapture. Although the loss in weight for A-1261 and A-1366 is similar, both are significantly different from the
third female, which gained 26% of her initial body mass (see below). Therefore, a cost estimation of reproduction can be approximated. Reproduction has been investigated for a congener, Sistrurus miliarius
barbouri (Farrell et al., 1995). The other recaptured female, A-1369, gained weight during the interval. Her initial body weight was 42.2g, and 133 days later she
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weighed 53.2g. This snake was not found to be at post-parturition at
either the capture date (24 April, 1996) or recapture date (5 September,
1996).
Three adult males, A-1352, A-1354 and A-1361, gained weight during the recapture interval; none of these intervals included an
overwintering period. A-1352 gained 4.3 g (9.1%) over a 132 day period
(47.4g to 51.7g), A-1354 gained 12.4g (42.8%) over a 133 day period
(29.Og to 41.4g), and A-1361 showed the most rapid weight gain, from
24.2g to 51.2g (111%), over a 149 day period. Five snakes, A-1258, A-
1352, A-1354, A-1366, and A-1369 gained at least 1 ratde segment
between capture and recapture. A-1258 gained one rattle segment,
indicating that the snake either shed after the original capture date of
26 September, 1995 and before hibernation or, more likely, after
emergence and before it was recaptured on 26 April the following year.
A-1352 and A-1369 shed once during the recapture intervals (132 and
133 days) indicating these snakes shed at least once during the
summer. A-1354 and A-1366 shed twice during the recapture intervals
(133 and 163 days) indicating a possible increased growth rate for these
snakes.
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. CM • • • 5C Male C-126 375/45 375/45 PIT Tag: PIT 2242127528 + 1 + 4C 5C 53.2 37.9 42.2 37.9 22/2 +11.0 PIT Tag: PIT 400/37 A-1369 378/35 4 14539754C +2 41 31 3C 163 133 11 -0.8 36.0 20/5 36.8 385/36 A-1366 365/31 Female Female PIT Tag: PIT 24-Apr-96 24-Apr-96 10-Sep-96 5-Oct-96 5-Sep-96 21-Sep-96 2242127528 • • • 149 24.2 +27.0 Male-fc A-1361 PIT Tag: Tag: PIT 21-Sep-96 in Lincoln County, Colorado. 22421B1B79 +2 41 21 133 41.4 51.2 29.0 + 12.4 + A-1354 PIT Tag: PIT catenatus 5-Sep-96 24-Apr-96 24-Apr-96 4145490766 21 132 +4.3 51.7 47.4 Male Male PIT Tag: PIT A-1352 373/47 336/44 320/14 4-Sep-96 26-Apr-96 414557374B 31 31 343 -1.6 383/32 390/49 375/45 376/16 A-1261 PIT Tag: Tag: PIT 365/32 Female 4-Sep-96 2242286729 41 31 4C 211 -8.2 53.6 40.6 61.8 42.2 A-1258 404/47 PIT Tag: Tag: PIT 395/47 26-Apr-96 22423F2808 Rattle#- I=incomplete; C=complete. ☆ denotes snake with posterior 2/3 of tail missing. denotes snake at post parturition. Data not calculated for C-126 due to lack ofa significant interval length. Difference Difference in weight Difference Difference in rattle#1 + -11 + Recapture Recapture interval Difference in length 9/1 18/0 17/2 39/1 55/2 Recapture Recapture length Recapture weight Recapture rattle# Recapture Recapture date Initial rattle# Initial Initial length Initial (mm) Capture dateCapture 26-Sep-95 26-Sep-95 Initial weight Initial (g) Gender Male Table 8. Capture and recapture data for PIT-tagged S.
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Age classes—Figure 16 shows sizes of massasaugas in the sample
from Colorado. Second year snakes (SVL 210-290) were uncommon and
accounted for 3.7% (n=9) of the total sample (n=240). This age class of
snakes probably stays near areas of birth where they forage for smaller prey items (lizards) until they reach sexual maturity during their third
calendar year (see below). Movement may be restricted for this age
class until matuity, when the search for a mate could result in an
increase in movement. The availability of larger prey (rodents) may
also influence this movement. Limited information on growth rate is
available from the recapture data (Table 8). The average length (N=12)
of postparturition females was 371.5mm SVL (SD ±28.3), with the
smallest at 325 mm SVL. Based on size distribution data, a 325 mm
snake is in its third calendar year (Figure 16), and it is likely that sexual maturation occurs at this time.
Snake growth rates varied; A-1261 lost 1.6g (3.8%) of her initial body weight at a rate of 0.004g/day. This snake continued to grow in length
during the interval (SVL 365-383). A-1366 lost 0.8g (2.2%) of her initial body weight at a rate of 0.005g/day. This snake also continued to grow
in length (SVL 365-385). A-1369 gained weight at a rate of 0.08g/day. This snake also grew in length during the interval (SVL 378-400). A-
1352 gained 4.3 g (9.1%) at a rate of 0.03g/day, while A-1354 gained
12.4g (42.8%) at a rate of 0.09g/day. Three males, A-1352, A-1354 and A-1361, gained weight during the recapture interval; none of these
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intervals included an overwintering period. A-1352 gained 4.3 g (9.1%)
over a 132 day period (47.4g to 51.7g); this is a growth rate of 0.03g/day.
A-1354 gained 12.4g (42.8%) over a 133 day period (29.0g to 41.4g). This
is a growth rate of 0.09g/day. A-1361 showed the most rapid weight gain, from 24.2g to 51.2g, over a 149 day period. This is an increase of 111.5% of its initial body weight
Two male snakes of young adult size, found 24 April, 1996, gained
weight between recaptures. The initial body weight of one snake (A-
1361) was 24.2 g, 149 days later (21 September) it weighed 51.2 g. This
is a growth rate of 0.18 g/day. When initially caught, it was believed to
be an immature snake with an adult length (320 SVL). The gain in
weight (122%) and in length (17.5%) suggests that the snake reached
reproductive maturity either during hibernation or some time during
the summer. The other snake, recaptured 16 days earlier (5
September), showed a slower growth rate, with an increase in weight of
12.4g over a 133 day period (0.09 g/day). This snake grew 39 mm
between captures (SVL 336-375). The growth rate of these two snakes compared to snakes that are larger (See Table 8) indicates that snakes with a SVL of 300-320mm are in their third year and are likely sexually
mature. Figure 16 also includes 5 likely age classes according to SVL % frequency distributions. First-year snakes ranged from 140-220 SVL.
Second-year snakes ranged from -240-295 SVL, while third-year snakes
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(the most abundant size class) ranged from -300-390 SVL. Fourth-year
snakes ranged from -395-460 SVL, and fifth-year snakes were 470+ mm
SVL. It is apparent that veiy few snakes live longer than 4 years.
24 22 20 U09 1 8 ■3 16 S 14 0 12 j i 10
1 8 2 6 4 2 0 MJL 120 160 200 240 280 320 360 400 440 480 SVL (mm) Figure 16. Snout-vent lengths (SVL) of S. catenatus in Colorado (n=240). Bars above histograms indicate approximate age classes (in years).
Reproduction
On 30 May, 1996, one DOR adult female massasauga (SVL = 380mm) was collected that contained 5 eggs that measured 27, 26, 26,
23 and 14 mm. Embryos were not visible but blood vessels were visible
within the eggs. Ten other female massasaugas were obviously at post-parturition: 3 in April, 4 in September and 3 in October. These
females were characterized by the posterior 2/5 of the body being thin and flaccid, with little or no muscle tone. The average length of
postparturition females was 371.5 mm SVL (SD ±28.3); the smallest
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was 325 mm. This contrasts strongly with S. c. catenatus, where the smallest gravid females were 501mm SVL in Missouri (Seigel, 1986),
448mm SVL in Pennsylvania (Reinert, 1981), 551mm SVL in Illinois
(Wright, 1941) and 559mm SVL in Wisconsin (Keenlyne, 1968).
Neonatal young are recognized by the presence of a yellow tail and
the button. Although umbilical scars were used by some investigators
as a characteristic of neonatal massasaugas (Seigel, 1986), umbilical scars were still apparent on most adults (SVL 300+) in Colorado. The
earliest appearance of neonates was 3 September, 1994 and the latest
appearance was 15 October, 1995. The neonate recovered on 15 October, 1995 was 140 mm SVL, the smallest snake found during the
study. No gravid females or birthings were observed, so sizes of
snakes immediately after birth were unavailable. The mean size of 24
neonates collected in the field was 192 ±16.2, so size at birth was
probably even smaller. Mean weight of 17 neonates from Colorado was
7.0 g ±1.2. Ten neonatal S. c. tergeminus bom in captivity to a female
from Cheyenne Bottoms, Barton County, Kansas, averaged 213.8 mm
±6.7. The mean weight for the 10 neonates from Kansas was 8.0 g
±0.5. Mean SVL for neonate massasaugas was reported by Seigel
(1986), Wright (1941), Reinert (1981) and Keenlyne (1968).
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Diet
Fixed slides of dried samples of fecal material from live snakes and
stomach contents of road-killed specimens were examined. Neonate massasaugas fed on lizards while adult snakes preferred small rodents
and lizards (Table 9). Perognathus flavescens and Reithrodontomys
megalotis hair samples were identified from 12 of the 15 slides.
Rodents were only found in adult massasaugas. The smallest snake
with rodent hair in fecal or gut contents was 300 mm SVL.
One neonate massasauga found DOR 8 October, 1996 had a
juvenile earless lizard (Hobrookia maculata)in its stomach. The lizard
was intact when the snake was dissected and was presumably eaten
within hours before the snake was killed. Gut content of one adult massasauga consisted of a partially digested adult fence lizard (Sceloporus undulatus), indicating adults also feed on lizards.
There are several reports of diet for the massasauga, but most are
based on a limited number of samples. Seigel (1986) reported
mammals (Microtis ochrogaster and Peromyscus sp.) and snakes ( Storeria dekayi and Thamnophis sirtalis) to make up the bulk of the diet for adult
and juvenile massasaugas, respectively, in Missouri. In Wisconsin,
Keenlyne and Beer (1973) found that nearly 95% of all food items for the massasauga were endotherms and 85% of those were Microtis
pennsylvanicus. Peromyscus leucopus, Thamnophis sirtalis, Zapus hudsonius, Agelaius phoeniceus and Sorex dnereus were also prey items.
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Table 9. Prey identified in fecal material or gut contents of S. catenatus from Colorado. # denotes gut contents.
Field/Museum Number S-V/Tail length Prey item ______(mm)______A-1303 320/29 Perognathus flavescens A-1314 310/36 Perognathus flavescens A-3138 420/62 Perognathus flavescens C-020 345/44 Perognathus flavescens C-050 300/37 Perognathus flavescens C-052 372/37 Perognathus flavescens C-093 330/41 Perognathus flavescens A-493 335/31 Peromyscus maniculatis A-1539# 380/32 Reithrodontomys megalotis A-2988 372/51 Reithrodontomys megalotis A-3046# 457/58 Reithrodontomys megalotis A-3139 375/35 Reithrodontomys megalotis A-3142 430/40 Reithrodontomys megalotis A-3150 N/A Reithrodontomys megalotis C-053 383/34 Reithrodontomys megalotis C-092 477/57 Reithrodontomys megalotis C-091 308/39 Rodent hair A-1261 365/34 centipede (Scolopendra sp.) A-1305 362/35 centipede (Scolopendra sp.) A-1243 175/20 Cnemidopkorus sexlineatus A-1282 370/32 Eumeces obsoletus C-293 363/33 Eumeces obsoletus C-344 165/19 Holbrookia maculata Neonate 10/4/96# Holbrookia maculata SM-793# 355/35 Holbrookia maculata C-052 372/37 insect remains A-2726 297/35 Lizard scales A-1308 325/40 Sceloporus undulatus A-1312 335/45 Sceloporus undulatus A-3001# 443/38 Sceloporus undulatus A-3122 297/35 Sceloporus undulatus C-082 375/31 Sceloporus undulatus CU-42373# 302/41 Spea bombifrons
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Predators
I observed 6 episodes of Swainson’s hawks {Buteo swainsoni) and
Northern Harriers (Circus cyaneus) capturing snakes and flying off with
them. Hawks were also seen eating snakes on the ground. Snake species was not identified, but captures were on summer days which
were warmer than massasauga temperature preferences. Efforts made
to scare the hawks into dropping snakes were unsuccessful. Ten
badgers were observed during the study period and most were at
massasauga localities. Badgers are presumed to be predators of
massasaugas (Ernst, 1992) although no observations were made of
these carnivores consuming snakes.
All dead snakes (N=102) were found on the road. Most were killed
by vehicles running them over, but two snakes dead on the road had
been mutilated by humans. One was decapitated and tailless, and the other was cut in half with a sharp object.
Line Intercept Analysis of Areal Cover
The dominant vegetation at transect locations was determined by the percentage cover of each classification. Results of 49 transects
performed 9-10 July, 1996 at massasauga locations indicate that grasses and litter were the two most common type of areal cover
(Figure 17). A box plot (Glass and Hopkins, 1996) illustrates
differences of areal cover between the sites. The box constitutes 50%
of the distribution of the total samples with the line in the box
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depicting the median. Figure 17 also displays values that deviate 1.5
times or less from the mean as line extensions from the boxes. The
circles represent outliers which deviate more than 1.5 times from the
25th and 75th percentile. The average value for percentage cover was
83.6% (range= 46.2%-100%). Grasses made up 58.3% (26.4%-81.3%) of the cover type followed by litter at 21.3% (4.4%-46.2%) and bare soil at
16.0% (0.0%-37.4%) respectively. Buffalo and blue grama were the
major grasses at all of the sites, and sand sage and yucca were the
most common shrubs. pH of the soils at 7 sites ranged from 6.1-6.75.
i.i
.9
.7
.5
.3
.1
-.1 Rock Bare soil Litter Grasses Porbs Shrubs Cacti Total cover Figure 17. Box plots depicting the percentages of rock, bare soil, litter, grasses, forbs, shrubs, cacti, and total ground cover at localities of S. catenatus in Colorado. Boxes constitute the middle 50% of the distribution. Lines are extensions to 1.5 deviations from the mean, and circles are outliers. The figure shows results for 49 sites combined.
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 63
Discussion
Extensive field work in southeastern Colorado was conducted to
determine distribution, life history, activity patterns, demographics,
reproduction, diet, predators and habitat characteristics for the massasauga in Colorado. Assessing these major biological
components has helped to identify critical habitat requirements for the massasauga in Colorado.
Distribution—At present, results (Table 2) suggest that the
distribution of the massasauga in Colorado is localized to a limited
portion of the southeast. Portions of the population of massasaugas appear small and scattered, but in several areas they are locally
abundant. Some locations are reliable any time between April and
October for massasauga encounters, while at other locations
massasaugas were uncommon, based on survey efforts. Outlying
populations exist (ie: Baca, Bent, El Paso, Las Animas, Otero and
Prowers Counties) and are in need of further study to determine if
these populations of massasaugas in Colorado have sufficient
recruitment habitat and prey bases for sustaining these populations.
Continued sampling of these areas will lead to a broader information base about populations in Colorado. Viable, healthy populations can
be a target for future conservation considerations. The massasauga in Colorado is a semi-arid grassland species as is true for the massasauga in northwestern Texas (Knoff and Tinkle,
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 6 4
1961), New Mexico (Degenhardt, 1996) and Arizona (A. Holycross). This
differs dramatically from the habitat of massasaugas in the east, where
wet grassland swampy conditions exist. Sistrurus a catenatus and S. c.
tergeminus utilize these moist lowlands for hibernation (Reinert, 1982; Seigel, 1986). Sistrurus. c. edwardsi is found in habitats in
southeastern Arizona and the southern half of New Mexico where the
soils are classified as Aridisols, equivalent to sites in Colorado. This
affinity for this soil type is a further justification for inclusion of
snakes with the edw ardsi subspecies (see Chapter 3) because of the
importance soils, together with precipitation patterns, have in
determining general vegetation and prey types and reflecting aridity of a
region. Soil and habitat types in turn will affect behaviors such as
activity patterns.
Areas with open short-grass prairie as the dominant vegetation and
where agriculture is limited to light grazing provide primary habitat
requirements for viable populations of the massasauga. One snake
was found in 1993 and two were found in 1994 at an area that had been
farmed 10 years prior. Non-native CRP-issued vegetation was planted
there as a replacement to provide cover for wildlife. Some native habitat is adjacent to these relatively small parcels of CRP and
therefore can act as a source for snakes while the more disturbed CRP may offer an adequate prey base. Therefore, recolonization of disturbed
areas is possible but probably restricted. CRP contracts have expired
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and land owners with land designated as CRP will have an option to
retill or retain the current vegetation of the land. Virtually all other
massasaugas were found in habitat consisting of short-grass prairie or the short-grass/sand-sage prairie association.
The eastern and southern fringes of the range of S. catenatus in
Colorado reach the western meridian 102.5° and the northern parallel
37.5°. There is reason to suspect that the populations in Colorado are currently disjunct from neighboring populations in New Mexico and
Kansas, because the known limits of the range of the massasauga in
these states is of a considerable distance from those in Colorado.
Morphometries of a single massasauga (KU #221506) from the high plains in Hamilton County, in extreme western Kansas, are quite
similar to snakes from Colorado which are also a high plains animal
(this study). The next neighboring population of S. catenatus to the
east is located in Kansas on a wildlife refuge managed primarily for
waterfowl. This refuge lies near the 99th meridian west at an elevation of 2000 ft above sea level. Here, the western subspecies, S. c.
tergeminus, persists in high numbers in lowland swampy conditions along the Arkansas River. In New Mexico, the massasauga ranges from the central region south and the northern-most locality is at the
35th parallel; elevations range from 925-2100 m pengenhardt, 1996). The massasauga in Arizona occupies habitat at an elevation around 1500 m and also inhabits a short-grass prairie habitat (A. Holycross,
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 66
pers. comm.). In Texas, near the disputed type locality (Stejneger,
1940), the massasauga occurs from the southeast to the north and
northwest as a low plains species to the east and a high plains species
to the west (Knoff and Tinkle, 1961). In western Texas, the elevation of the range is similar to that of Colorado S. catenatus and S. a
edwardsi.
It is not known whether the apparent range disjunction for Colorado
is due to recent human modifications to the environment or if it
represents a longer-term contraction of a formerly wide-spread
desert/grassland species. The Mesa de Maya and Raton Mesa regions
in southeastern Colorado may provide a historic and current geographic
barrier from the populations of massasaugas in New Mexico. Either
way, human activity has accelerated the pattern of occurrence.
The county distributions provide a detailed view of the habitat
association and the distribution of the massasauga in that county.
Managers can look at how lands are used at these areas of the county
and determine if the utilization of that land is promoting the continued
existence of the massasauga. They can also make recommendations
and provide incentives to landowners to preserve the habitat where the snakes exist. This distribution information can also help identify
patterns of abundance which can help managers decide if that area is
needed as a parcel for conservation or monitoring.
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 67
Movement—Most live massasaugas were collected during the day in
the spring (April and beginning of May) and fall (middle September to
October) when they apparently move to and from hibemacula. During warmer weather (summer), snakes apparently switch to patterns of
nocturnal movement. When conditions are hot and dry, movements appear to be much less frequent and observations were limited.
Numerous small mammalian burrows could provide shelter during the
day in hot summer months, but observations of the diurnal habits of
the massasauga during this time were few. The general pattern of activity was that snakes in April were active from mid-morning to early
afternoon. From May until mid-September, snake activity was
restricted to a window of time just after dark until just after midnight
(usually~20:00-22:00 hrs). After middle of September, snakes became
active mid to late afternoon but not after dark. During late September
until the last recorded observations, usually mid-October, snakes were
seen during the late morning. At these activity times, temperatures
are tolerable and favorable for massasauga movement. During the
spring and fall, temperatures are favorable during the late morning and early afternoon. This reflects optimal temperatures during those cool months as the early mornings and late afternoons become too cold. Late-night temperatures during summer months provide adequate
temperatures for movement. Discovering specific movement, activity
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patterns and habitat use will require the use of radiotelemetry (see Reinert, 1993).
Loamy soils are structurally more resistant to the weight of large
herbivorous mammals such as bison or cattle, and mammal burrows in
this compact soil may provide adequate hibemacula that minimize the
potential for collapse. Along a road at one site in Lincoln County,
massasaugas moved from west to east in the spring and reversed this
movement in the fall. Habitat to the west is short-grass prairie
associated with loamy soils. The habitat to the east is sand-sage,
associated with sandy, loamy soils where prey items are more abundant. This movement to loose sandy soil in the spring appears to
be the result of the attraction to the abundant Plains Pocket Mouse
{Perognathus flavescens) and Plains Harvest Mouse ( Reithrodontomys
montanus) which live on loose sandy soils. Here, young Kangaroo Rats
[Dipodomys ordii) may also be taken as prey, while the burrows of the
adults may provide refugia in the summer. Weedy and disturbed areas
and tall stands of grasses are characteristic of road-side vegetation,
and this provides suitable habitat for the Western Harvest Mouse
(Reithrodontomys megalotis) (Fitzgerald et al., 1994; Mohamed, 1989). These small rodents, which are not abundant on loamy soils, were found to make up part of the primary diet of adult massasaugas in
Colorado (see Table 9). Infrequent to occasional occurrences of this
prey in loamy soils likely result the relatively lower encounters with
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snakes, but live trapping of small mice in the loamy soils is needed to assess this hypothesis. On the other hand, the fragile nature and
aridity of the sandy soils may prohibit massasaugas from hibernating in this area. The occurrence of an abundant prey base in one area and
the appropriate hibemacula in another may account for the movement
east in the spring following emergence and west (over the road) to the harder, loamy soil during the period ju st before ingression.
Patterns of abundance of massasaugas also reflect habitat
differences between sites. Native grasslands in the southeastern
region of Colorado are stable in areas where tilling and farming are not
productive for residents and have not been attempted. Seasonal
movements in the spring for massasaugas in Colorado, from short- grass prairie with hard, loamy soils to sand-sage habitat with softer,
more sandy soils, is reminiscent of the movements of the massasauga
in the eastern United States. Here, they move from moist, soggy
conditions to a drier, grassland condition in the spring and reverse this movement in the fall (Seigel, 1986). In Colorado, as in much of the massasauga range, appropriate areas are becoming increasingly
fragmented and may result in a few isolated islands of suitable habitat
where the massasauga becomes more susceptible to human activity.
Life History Characteristics. Body size and sexual dimorphism—There was no difference in average
adult male and female lengths, although the longest and heaviest
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snake collected was a male; most of the larger snakes were males, and females averaged almost lOg lighter than males (Table 4). Therefore,
there is a difference in average body size. Typically, male and female
sizes are approximately the same, but larger snakes are male and, as a result, sex ratio data of smaller snakes may be skewed toward females.
Sexual dimorphism occurred for tail length relative to snout-vent
length. The ratio for females was 0.092, and for males it was 0.12;
these ratios are very similar to the results of Seigel (1986) with S.
catenatus in Missouri.
Activity patterns- Temperatures at times of massasauga movement
ranged from 14-30 °C with 62% of captures between 20 and 24 °C (Table
5). Ambient temperatures have been recorded in June, July and August to reach 36 °C, often rising above 38 °C in July and August
(NOAA, 1996). Temperatures during the evening and early morning
consistently drop to between 14 and 16 °C, providing a narrow time
window of tolerable temperatures for movement during the summer.
Temperature preferences (during movements) for massasaugas in
Colorado were generally cooler than for most reptiles at the study area although the prairie rattlesnake ( Crotalus viridis inridis), glossy snake (Arizona elegans), milk snake [Lampropeltis triangulum) and hognose
snake (Heterodon nasicus) were also active at times when massasaugas were active. Collectively, encounters with these snakes were not as frequent as encounters with massasaugas at these temperatures.
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However, biases of collecting efforts, the secretive nature of the glossy
snake and milk snake and the lack of rocky outcrops for prairie
rattlesnake hibemacula near most massasauga localities may have influenced this finding.
Results of massasauga encounters during each month may reflect patterns of seasonal movement (Table 6). April activity accounted for
movement out of hibemacula and to appropriate foraging sites (see
above). May and June may be times of copulation followed by solitary
activity, resulting in a lower level of encounters with snakes. Because
the female-male sex ratio of the sample is approximately 1:1.5,
searching by males for females may not be as extensive and time-
consuming as for other species. Apparent increases in activity during
July and August may reflect the requirement to forage in order to
increase overwintering body fat. Diurnal movements during September
and October likely reflect end-of-the-season foraging efforts and a
return to hibemacula.
Seasonal changes in activity may also depend on the time of day (Table 7). Most snakes were located while migrating from and to
hibernation during daylight hours in the spring and fall. Massasauga activity at this time may not be dependent simply on temperature but also on a biological time reference, for instance, biological rhythms or
clocks or a possible sun compass as is found in some reptiles (Graham et al, 1996). Other factors such as microhabitat climate, wind speed,
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soil temperature and moisture may influence activity patterns. With the large range of temperatures and precipitation fluctuations at the
study area, specific irregularities of climate may determine snak-**
movement at certain times of the year. In April, temperatures still
frequently drop below freezing. Subsequently, short, rapid, diurnal
movements from hibemacula occur until temperatures are reliably and consistently above freezing, usually around the first week in May, when
copulation is assumed to take place and nocturnal activity begins to
predominate.
Demographics-Adult male and female massasaugas in Colorado
averaged 355 mm and 352 mm (Table 4); these were not significantly
different. Based on growth rates (Table 8), observations of post
parturient females, movements of adult (SVL>300) and neonate
(SVL=160-190) massasaugas and a low number of snakes found within
SVL 210-290 mm, snakes reach sexual maturity sometime during their
third summer. Second year snakes may remain close to birthing sites to forage for appropriate-sized food until they can forage on larger, more
nutritional food sources (see below). Snakes in Colorado appear to
have a rapid growth rate potential until at least sexual maturity. One male (A-1361) gained 111% of initial body weight over a 163 day period, suggesting an initial rapid foraging strategy to reach adult size followed
by a tapering off of the growth rate. Sizes of the massasauga populations in Colorado were not possible to estimate. Estimates of
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sizes of age classes (Figure 16) were found to be 160-190 SVL for
neonates; 210-290 SVL for second year snakes; and 300-< 400 SVL for
third year snakes. Older female adults may not grow as large as male
adults, and the largest female found was 453 SVL (B-774), with 6
additional females 400 mm SVL or more. Twenty-three males were over
400 SVL, and the largest (A-1193) was 485 SVL and estimated to be
perhaps 10 years of age (Appendix 1). This estimate was made based
on a snake held in captivity for more than 10 years, which was actually
smaller than the snake found (A-1193).
At one site in Lincoln County, significant recruitment to the
population occurs, based on the number of neonates found in the fall
(N=24). From the 8 recaptures (Table 8), population size for the area in
Lincoln County (35 km2) may be estimated at 900 using the Peterson index, but an actual estimate must be obtained by using the Schnabel
method which accounts for repeated marking and recapture (Cox, 1996);
this method was not implemented for this study. Population parameters can be defined specifically if a boundary around the
proposed population was set. Radiotelemetry can assist in acquiring
data useful for this, but size and weight limitations usually restrict radiotagging to the largest individuals of the population. Reproduction—Results suggest that massasaugas copulate in late
April and early May or may have the capacity of sperm storage. However, in fall of 1994 a male was found on top of a female, and
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copulation therefore may occur in the fall. One DOR female snake
collected on 30 May, 1996 was gravid. Clutch size is uncertain, but
this snake contained 5 eggs which had well-developed blood vessels
and appeared to be fertile [(23-27 mm diameter, N=4, with one
rudimentary egg (14 mm)]. One clutch for S. a tergeminus from
Cheyenne Bottoms, Barton County, Kansas consisted of 10 young (this
study). Neonatal snake sizes in Colorado are unknown; however, 24
snakes were found with yellow tails and buttons; and average size was
smaller (192 mm) than S. c. catenatus (Swanson, 1933; Wright, 1941;
Greene and Oliver, 1965; Keenlyne, 1978; Reinert, 1981; Seigel, 1986)
and S. c. tergeminus neonates (Greene and Oliver, 1965). However, one
snake is not a sufficient sample for determining clutch sizes for
massasaugas in Colorado. Captive breeding in laboratory conditions
may help elucidate typical clutch size if gravid females can not be
obtained in the field.
Pret/—Results of examinations of fecal material and stomach
contents reveal that neonates and juveniles feed mainly on lizards
(Cnemidophorus sexlmeatus, Eumeces obsoletus, Holbrookia maculata, and
Sceloporus undulatus) until they can forage on larger, more nutritional
food sources ( Perognathis flavescens and Reithrodontomys megalotis, Table
9). Adults feed primarily on small mice, but lizards, centipedes
[Scolopendra sp.Jand spadefoot toads ( Spea bombifrons)aie also occasionally taken (Table 9). Juveniles probably rely on small lizards
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as food sources due to size constraints, while adults probably feed on
small rodents and other smaller prey; perhaps for an increased caloric content. Ontogenetic shifts in diet have been seen in other
rattlesnakes (e.g., Mackessy, 1988), but small adult size of Colorado
massasaugas may force them to be more opportunistic in diet.
Predators—There were no observations of predation on massasaugas
but the most common potential predators observed were hawks,
badgers, coyotes, foxes, other snakes and bullfrogs. Additional
potential predators that were observed in the range of the massasauga
include long-tailed weasels, skunks, raccoons, burrowing owls and
great-homed owls.
Areal couerage-Short.~gra.ss prairie was the dominant habitat type
occupied by the massasauga, including a high percentage of ground
cover conditions. This type of habitat, associated with sand-sage
habitat, was found at areas where massasaugas were the most
common reptile. This type of habitat association is uncommon in the
study area except directly south along Big Sandy Creek. At areas
lacking these habitat associations, massasaugas were not common, although they were found. Results (Figure 17) show short grasses and
litter as the two most frequent types of ground cover at locations of
snakes. Habitat conditions at snake localities consisted mainly of
native species of vegetation. Areas that were farmed and with intense grazing were not characteristics of snake locations. Roadside
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vegetation at some locations consisted mainly of tall exotic vegetation
and snakes may have an affinity for this because of runoff and heat
retention, attributes roads possess. Sand-sage habitat with yucca was
closely associated with higher densities of massasaugas. This may
provide additional refugia from extreme temperatures and adequate prey with an abundance of rodent burrows to support the relatively high
number of encounters these areas.
Many factors influence where a snake lives and how it chooses its
preferred habitat. This study addresses much of the preliminary
qualities, including specific localities, overall distribution of
massasaugas and expected habitat required for snake occurrences.
This information is useful for general habitat utilization studies. The obvious tool that is missing for studying habitat utilization for snakes
is radiotelemetiy. Following daily movements of snakes under natural
conditions is an ideal way of examining behavioral patterns, habitat
use and life history characteristics.
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MORPHOLOGICAL VARIATION AND TAXONOMIC STATUS OF THE MASSASAUGA IN COLORADO
Introduction
Within the Sistrurus catenatus complex, three described subspecies,
catenatus, tergeminus and edwardsi, have been distinguished by
morphometric data (Conant and Collins, 1991; Gloyd, 1955 8s 1940;
Klauber, 1972 8s 1936). Klauber (1936) described only catenatus and
tergeminus, the latter including snakes “from extreme southeastern
Colorado; ...the plains areas of central and southern New Mexico;
extreme southeastern Arizona.” Gloyd (1955) reviewed the
massasaugas of the southwestern United States and included the only
known specimen from an unknown locality in Colorado as edwardsi. (It has been determined that this specimen was collected in 1882 by Mr.
A. E. Beardsley in Baca County, Colorado, and is listed as voucher #96-
265 in the “Colorado State Normal College” museum register; see
Chapter 2 for comments on specimen). Wright and Wright (1957)
described specimens from western Missouri and southeastern
Nebraska to southeastern Arizona and extreme northern Mexico as
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tergeminus. Massasaugas in Colorado were included in tergeminus until
Maslin (1965) described S. catenatus from Colorado as an intergrade
between tergeminus and edw ardsi. Maslin’s classification of S.
catenatus in Colorado has been considered valid since that Hrpe
(Conant and Collins, 1991); however, Maslin indicated that a more thorough investigation was needed and emphasized the need for more
material. Maslin (1965) further noted scale characters of the Colorado
population may be "so distinctive that nomenclatural recognition of
this biological entity might be justified."
Prior investigations have demonstrated the utility of scale counts
when examining rattlesnake taxonomy (Reinert, 1978; Klauber, 1972;
Gloyd, 1940; Klauber, 1936). Many snake species are described by specific scale counts at various locations on the body; these
morphometric characters represent a set of unique character states
useful in defining subspecies and in identification. Scale characters
exhibit subspecific variation in the Sistrurus catenatus complex, and
scale counts have been completed on many populations with the
exception of snakes in Colorado (Reinert, 1978; Gloyd, 1940). Gloyd
(1955) described the most useful characters for differentiating between the three subspecies of Sistrurus catenatus: number of dorsal scale
rows at midbody and immediately anterior to the anus; number of
ventral and subcaudal scales; total length; percent of tail to total
length; and number of body blotches.
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The taxonomic status of the massasauga in Colorado is uncertain
due to a lack of specimens from Colorado and adjoining states.
Maslin’s study (1965), was based on 12 specimens, 6 of which are from
Kiowa County. At that time, with a small sample size, including only one female, and without adequate numbers of specimens from
adjoining counties, classifying the massasauga in Colorado as an intergrade was tentative. Since the latest published range map by
Hammerson (1986), this study has added 3 counties in Colorado to the
range of the massasauga (Hobert et al., 1997; Mackessy et al., 1996;
Hammerson, 1991) and I have examined 268 specimens. In addition,
more specimens have become available from New Mexico and Arizona
as a result of collecting efforts since the reviews by Gloyd (1955) and
Maslin (1965). There is now sufficient data and specimens to examine
the question of the taxonomic status of the Colorado population in
more detail. Materials and Methods
Specimens
A total of 268 massasaugas from 10 counties in Colorado were
examined for morphological variations. The museum at the University of Colorado provided 14 of those specimens; of the other 254, 155 were
found alive, processed and released during the study period. The
University of Northern Colorado Museum of Natural History currently houses 99 road-killed massasaugas as preserved specimens.
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Thirty-four museum specimens of S. c. edw ardsi from Arizona State
University (Andrew Holycross) and 31 museum specimens from the
Museum of Southwestern Biology at the University of New Mexico (Don Sias) were examined for morphometries. Forty-one specimens of S. c.
tergeminus from the Museum of Natural History at the University of
Kansas (John Simmons) were examined and 12 live S. c. tergeminus from Cheyenne Bottoms National Wildlife Refuge, Barton County,
Kansas, were also examined for the thirteen characters listed below.
Catalog numbers of specimens examined are given in Appendices 1, 2
and 3. Retained live snakes from Colorado and Kansas are currently
being maintained in the Animal Facility at the University of Northern Colorado.
Measuring Morphological Characters
Coloration-Colors were determined by examining live specimens or
preserved specimens retaining the original color. For some specimens,
colors were not scored due to extensive fading from preservation
material. Ground color, body blotch color and ventral color were described as qualitative characters. The arrangement of ventral
coloration was scored as peripheral (laterally), random speckling or intermediate between the two. Percent of ventral surface which was
darkly colored was estimated. Scutullatiort-Samples of preserved specimens, shed skins of live
snakes and live snakes tubed in 1.8cm and 1.5cm glass tubing were
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utilized for scale counting. Body measurements to the nearest mm
(live snakes, fresh road kills) were recorded by using a small metric
ruler and a meter stick. Scale counts for preserved specimens were recorded with the aid of a dissecting microscope (see Chapter 2 for
make and model). Twelve measurements (see below), including scale
counts, were recorded for each specimen as suggested by prior
investigators (Reinert, 1978; Klauber, 1972 & 1936; Schmidt and Davis, 1941).
Specimens that were badly damaged or in a condition where scale
counts and colorations could not be recorded accurately were not
included as sources of data in the scale tabulations (see appendices).
Some specimens were in a condition so that only certain scale characters could be counted. Scale counts and measurements for each massasauga were performed for the following areas of the body as
suggested by Klauber (1936):
1. Number of dorsal scale rou/s-Dorsal scale rows begin with the row
next to the ventrals on one side and end with the corresponding row on the other. These were measured at one head length posterior to rictus
of jaw, at mid-body, immediately anterior to anus and at mid-tail. 2. Ventral scales-V entrals were counted beginning with the initial scale
under the head that is wider than long and end with the scale
immediately anterior to the anal plate. Divided ventrals were counted
as one ventral scale.
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3. Subcaudah-These are the scales that start immediately posterior to
the anal plate and end anterior to the proximal rattle (basal rattle).
Divided subcaudals were counted as one subcaudal scale.
4. Labials -These scales run above and below the mouth from, but not
including, the rostral and mental scales to the comer of the mouth.
The supralabials (above) and infralabials (below) were counted
separately and for each side of the mouth.
5. Oculars-^These scales surround the eye. The oculars include the
suboculars, postoculars, supraoculars and preoculars.
6. Body blotches-Blotches were counted from the first blotch not
continuous with the lyreform to the blotch immediately above the anal
plate. Tail bands were not included.
7. Tail bands -These were the dorsal bands between the anus and the proximal rattle. These are often of more than one color, but all are
counted as tail bands.
8. Head length and width -Head length measurement (mm) is from the
rostral scale to the point of articulation of the mandible and
pterygoid/quadrate bones. Head width is widest portion of head,
between points of articulation mentioned above. 9. Snout/ vent length (SVL) -This is the total length of the body (mm)
from tip of snout to anus. 10. Tail length (TL) -Tail length (mm) was measured from the anus to
the proximal (basal) rattle.
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11. Lyreform-The shape and extent of the lyreform marking on the head
and neck was recorded as an intact lyre or discontinuous on right or left side.
12. Rattle segments-^The total number of rattle segments were counted.
This total included the proximal rattle segment and whether the string of rattles was complete (having the button) or incomplete (button
broken off).
Statistical Analysis- Student’s t-tests were performed for comparative
analyses between S. catenatus in Colorado, S. c. edwardsi , and S. c.
tergeminus (c. f. Campbell and Armstrong, 1979). Unless otherwise
noted, the value used for statistical significance was 0.05. Means and
standard deviations (SD) were computed for the morphometric values.
Results
Results indicate that values for coloration, scutullation and mensural characteristics of Colorado massasaugas and S. c. edw ardsi
more closely resembled each other than S. c. tergeminus did with
Colorado snakes or with S. c. edwardsi. Distinctive differences in color existed between specimens from Kansas ( tergeminus) and specimens from Colorado, New Mexico ( edwardsi ) and Arizona {edwardsi). Results
of scale counts followed this same pattern. Although some character
differences were not statistically significant, overall resemblance
between Colorado snakes and S. c. edwardsi was much more pronounced than between either and S. c. tergeminus.
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General coloration of S. c. tergeminus differed from Colorado snakes
and S. c. edw ardsi (Table 10). Ground color proportions for gray were similar for Colorado snakes (119/219) and edw ardsi (29/66), while only
one S. c. tergeminus specimen had a gray ground color (1/29). Body
blotch color for the three groups was variable, ranging from olive brown
to dark gray, although no S. c. tergeminus specimens possessed a blotch
color of olive brown. Ventral coloration ranged from dark brown to an
immaculate white with no coloration for the three groups. Dark brown
was the most frequent ventral coloration among all three. Average
percent colored ventral surface for Colorado snakes (19.2%) and
edwardsi (13.2%) was notably different than S. c. tergeminus (43.2%). Ventral pattern arrangement was also similar in proportion between Colorado snakes and S. c. edwardsi (Table 10).
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Table 10. Comparison of coloration for S. catenatus from Colorado, New Mexico and Arizona (edwardsif and from Kansas [tergeminus).
______Colorado snakes S. c. edwardsi S. c. tergeminus Ground color: gray 119 29 l light gray 20 3 0 dark gray 13 3 6 gray/brown 36 10 4 light brown 19 16 8 brown 12 5 10 Total 219 66 29
Body blotch color: olive brown 105 6 0 brown 45 19 3 dark brown 54 25 25 dark gray 15 15 1 Total 219 65 29
Ventral color: dark brown 139 44 25 brown 44 10 2 gray 9 0 0 dark gray 25 12 2 white/cream 1 0 0 Total 218 66 29
Ventral pattern arrangement: none 1 0 0 peripheral 64 17 9 random 67 18 9 intermediate 102 30 4 Total 234 65 22
Ventral surface: Ave. % colored ±SD 19.2 ±9.3 13.2 ±7.1 43.2 ±12.7
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Mean values, standard deviations, ranges and sample numbers for
morphometric data measured for Colorado snakes, S. c. edw ardsi and
S. c. tergem inus are given in Table 11. Sex-biased variation was present
for number of ventrals, subcaudals, tail bands, and tail to snout-vent
length ratio for the three subspecies; therefore, means and standard
deviations for these characters were calculated separately for each sex.
Mean dorsal scale rows at one headlength posterior from jaw for
Colorado snakes (23.13) and S. c. edw ardsi (23.16) were essentially
identical, while the mean for S. c. tergeminus (24.84) was notably
different. Mid-body dorsal scale rows were also similar in value for Colorado snakes (23.28) and S. c. edw ardsi (22.92) with ranges between 21 and 25. Sistrurus c. tergeminus averaged 25.03 and ranged 23-27.
The mean for dorsal scale rows directly anterior to the anus for
Colorado snakes was 18.4 and ranged 12-21. For S. c. edwardsi, values
were 18.25 and 16-21. Sistrurus c. tergeminus averaged 19.12 with a
range between 17 and 21. Mid-tail dorsal scale row means and ranges
for Colorado snakes, S. c. edwardsi and S. c. tergeminus were 10.8 (8-
13); 10.96 (8-14); and 11.74 (9-18) respectively. Means of supralabial
and infralabial scales were approximately the same for all three groups,
though S. c. tergeminus averages were slightly higher. There were also
no notable differences in ocular scale numbers for the three groups. Body blotches ranged from 30 to 46 for all snakes examined and were
variable within groups. The mean for S. c. edwardsi (35.7, SD±2.5) was
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slightly lower than the values for Colorado snakes (37.8, SD±3.2) and S. c. tergeminus (38.6, SD±3.4).
Ventral scale counts for Colorado and S. c. edwardsi were almost identical for males and females (143.7 to 143.4, males, and 147.2 to
147.3, females, respectively), while S. c. tergeminus means were slightly
higher (147.5 and 149.6). Subcaudal scale number for snakes from
Colorado averaged slightly less than S. c. edwardsi and S. c. tergeminus.
Subcaudal scales for male Colorado snakes averaged 28.2 and varied between 20 and 33. Values for S. c. edw ardsi and S. c. tergeminus
males were 30.5 (24-34) and 29.1 (24-32) respectively. The mean for
females from Colorado was 23.3 and varied between 16 and 29. Subcaudals for female S. c. edw ardsi and S. c. tergeminus were almost
identical (25.1 and 25.7) and ranged 23 to 28 and 22 to 29. Tail bands
for Colorado snakes averaged 7.7 for males and 6.2 for females, similar
to values for S. c. edwardsi (7.4 and 6.2) and S. c. tergeminus (7.6 and
6.6). Tail length (TL) to snout-vent length (SVL) ratios were roughly the
same for the three groups and correspond to findings of other
investigators (see Chapter 2). Some morphometric characters mentioned above showed
statistically significant differences between the three groups and are
enumerated below.
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 00 00 16 11 12 19 19 12 12 12 N 28 30 29 30 29 29 32 34 7-9 5-10 11-13 10-13 10-13 22-29 23-25 23-27 Range 140-158 20 314-641 tergeminus S. c. c. S. 12.3 ±0.8412.3 10-14 0.12 ±0.008 0.11-0.14 0.12 ±0.008 25.67 25.67 ±1.97 11.74 ±1.7511.74 9-18 ±0.71 11.83 31 19.12 ±0.8319.12 17-21 32 Mean ±SD Mean 38.55 38.55 ±3.40 32-46 33 25.03 25.03 ±0.63 147.45 ±3.65 147.45 0.093 0.07-0.100.093 ±0.009 478.42 478.42 ±84.7 59 N 40 29.11 ±2.16 24-32 40 71 6868 ±0.79 12.24 66 7.57 ±0.63 7.71 ±0.53 6-9 67 65 65 ±0.72 11.66 68 69 24.84 ±0.45 71 from Colorado, Arizona and New 5-8 31 6.58 ±0.90 5-8 7-9 5-10 40 7.63 ±1.21 8-14 71 11-13 23-28 31 10-13 10-13 24-34 16-21 30-41 21-25 21-26 Range 140-156 30 ±3.50 149.58 143-155 catenatus S. c. edtuardsi c. S. 0.13 0.13 ±0.01 0.09-0.15 40 6.19 6.19 ±0.87 7.76 7.76 ±0.50 7-9 11.88 ±0.64 11.88 11.97 ±0.71 11.97 25.19 25.19 ±1.33 18.25 ±1.01 18.25 10.96 ±0.93 10.96 ±0.62 11.35 ±0.6811.43 10-13 30.53 30.53 ±1.87 35.73 35.73 ±2.50 147.33 ±3.41 147.33 97 0.100.08-0.12 ±0.01 31 95 141 193 353.95 ±33.1 304-465 146 7.43 ±1.13 137 ±3.14 143.37 137-152 209 7.90 ±0.49 218 241 22.92 ±0.82 231 229 23.16 ±1.15 4-8 98 6-9 5-11 9-15 catenatus (S. c. tergeminus). 16-29 31-47 242 20-25 137-153 Colorado S. S. Colorado 6.17 6.17 ±1.01 7.72 7.72 ±0.52 6-9 209 7.68 ±0.54 ) ) and Kansas 11.67 ±0.82 11.67 10.78 ±0.9510.78 8-13 236 Mean ±SD Mean Range N ±SD Mean 23.13 23.13 ±0.90 23.28 23.28 ±0.78 21-25 147.20 ±2.84147.20 141-159 97 143.72 ±2.65 143.72 361.63 ±37.6 300-485 (S. c. edwardsi MalesFemales 0.12 ±0.01 0.09 0.095-0.16±0.01 0.08-0.11 Females Males 7.73 ±1.22 Females 23.35 ±1.90 Males 28.19 ±1.99 20-33 143 Females Males One headOne length Midtail Anterior to anusAnterior ±1.06 18.39 12-21 Midbody SVL (adults) SVL Tail/SVL Tail/SVL ratio: Subcaudals: Tail Tail bands: Left oculars Left Body blotchesBody Ventrals; 37,8 ±3.15 Right oculars Right Flight supralabialsFlight ±0.66 11.39 9-13 223 Right Right infralabials infralabials Left ±0.80 11,67 10-14 218 Left supralabialsLeft ±0.65 11.43 10-13 220 Dorsal Dorsal scale rows: Character Mexico Mexico Table 11. Meristic and mensural comparisons of samples of S.
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Table 12 shows results of Student’s t-tests which indicate
significant differences (P<0.05) between the means of the populations
with a hypothesized difference of zero (Ho: 111* 112* 113). Significant
differences occurred between means for the Colorado snakes and
edw ardsi with tergeminus for dorsal scale row numbers at one
headlength posterior from the jaw, at mid-body, and directly anterior to
the anus. Significant differences (P<0.05) are also evident for ventral
scale counts. There were no significant differences of body blotch number between Colorado snakes and tergeminus and edwardsi and
tergeminus, although differences in body blotch number between
Colorado snakes and edwardsi (P<0.0001), and edw ardsi and tergeminus
(P=0.005) were highly significant. Gloyd (1955) reviewed S. catenatus of
the southwest and distinguished edw ardsi from tergeminus in having a
paler coloration, 23 scale rows at midbody, lower number of ventrals
and lower number of dorsal blotches. This scenario holds true for
Colorado snakes and for edw ardsi except for body blotch number, which
is highly variable among all subspecies, and blotch number should be regarded as a poor diagnostic character.
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Table 12. Student’s t-tests of paired means comparison of scale counts between S. catenatus from Colorado, S. c. edwardsi, and S. c. tergeminus.
Character Mean Diff. DF t-Value P-Value Dorsal Scales: One head length Colorado and edwardsi -0.424 65 -2.253 0.028* Colorado and tergeminus -2.345 28 -11.052 <0.0001* edwardsi and tergeminus -1.724 28 -8.713 <0.0001* Midbody Colorado and edwardsi 0.366 70 2.952 0.004* Colorado and tergeminus -1.735 33 -10.866 <0.0001* edwardsi and tergeminus -1.939 32 -11.936 <0.0001* Anterior to anus Colorado and edwardsi 0.176 67 -0.869 0.388 Colorado and tergeminus -1.094 31 -4.574 <0.0001* edwardsi and tergeminus -1.276 28 -5.052 <0.0001* Midtail Colorado and edwardsi -0.254 70 -1.390 0.169 Colorado and tergeminus -0.935 30 -2.584 0.015* edwardsi and tergeminus -0.867 29 -2.119 0.043* Ventrals Colorado and edwardsi 0.206 67 0.310 0.758 Colorado and tergeminus -3.00 28 -3.019 0.005* edwardsi and tergeminus -3.90 29 -4.193 0.0002* Right supralabials Colorado and edwardsi -0.109 63 -1.000 0.321 Colorado and tergeminus -0.286 27 -1.492 0.147 edwardsi and tergeminus 0.130 22 -0.768 0.451 Left supralabials Colorado and edwardsi -0.108 64 -0.880 0.382 Colorado and tergeminus -0.444 26 -2.199 0.037* edwardsi and tergeminus -0.385 25 -1.848 0.077 Right infralabials Colorado and edwardsi -0.565 61 -3.805 0.0003* Colorado and tergeminus -0.889 26 -3.245 0.001* edwardsi and tergeminus -0.577 25 -2.440 0.022*
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Table 12 continued.
Character Mean Diff. DF t-Value P-Value Left infralabials Colorado and edwardsi -0.531 63 -3.518 0.001* Colorado and tergeminus -0.923 25 -4.308 0.0002* edwardsi and tergeminus -0.400 24 -1.852 0.076 Right oculars Colorado and edwardsi -0.234 63 -2.572 0.013* Colorado and tergeminus 0.269 25 1.895 0.07 edwardsi and tergeminus 0.296 26 2.126 0.043* Left oculars Colorado and edwardsi -0.095 62 -1.137 0.260 Colorado and tergeminus 0.0 23 0.0 <1 edwardsi and tergeminus 0.080 24 0.464 0.647 Body blotches Colorado and edwardsi 2.783 68 5.485 <0.0001* Colorado and tergeminus -0.250 31 -0.314 0.756 edwardsi and tergeminus -2.00 31 -2.989 0.005* DF= degrees of freedom Mean Diff.= difference of the means hypothesized difference -0; Ho: M.i=M-2=H3- * = significant difference
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The main character used by investigators to differentiate
subspecies of S. catenatus is number of dorsal scale rows at mid-body.
Figures 18, 19 and 20 illustrate differences in number of dorsal scale
rows at mid-body for all three groups examined for this study. General frequencies for this character strongly suggest that Colorado snakes
and S. c. edwardsi should be grouped together. Although results of t-
tests for this character indicate a statistically significant difference
between Colorado snakes and S. c. edwardsi (Table 10), the frequencies of the character states strongly support inclusion of Colorado snakes
in the subspecies edwardsi.
200 * 111 1 1 ‘ 1 1 ■ ‘ * * * ‘ * * 1 1 • ‘ * ‘■ 1• * 1 1 * * 1 ^ ‘ 1 ■ L . . » ■ ■ . . t . ■ i . ....i ....| 180 - 160 - CO Jg 140 * w g 120 : : 0 1 0 0 - nfe 80 - 6 1 6 0 : : 40 - -
20 - ______
0 i i"ii *i i i | i » i | i i^r r | i i *r < t U -i* | i i r r ; » i r t 20 21 22 23 24 25 26 27 28 Scale rows @ midbody Figure 18. Histogram of number of dorsal scale rows at mid-body for Sistrurus catenatus from Colorado.
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60 _J _ j. I .... I .... I .... I
50 03 V ^ 4 0 § Cm 0 30 Vu S i 1 20 2 10
0 ^ i i ' t i t t ' i1 -i- [■ r i 1 'i ■ *r i- |i i ■ i^rt ” it -| ■[ r i r r *i ^ i -i i 11 | i i i | i -i -I i i | I 1-1i - i i i - 20 21 22 23 24 25 26 27 28 Scale rows @ midbody Figure 19. Histogram of number of dorsal scale rows at mid-body for Sistrurus catenatus edwardsi (Arizona and New Mexico).
35 ■ ‘ ■ * 1 ■ » ‘ * 1 * ‘ * ■ 1 ‘ ‘ ‘ " 1 - ■-' 1 J ■ 1 1 ■ 1 * l
30
8 25 co « 20 Cmo U 15 e Z 10 5
0 ~I-i- r i r p >’i i ~r*T » ii *r* r t t 'I 1111 ni*i 'i■! | | i i i in t | i i *r iI" |I i I 'I im Ml i | I ■ iI r*i !■ J*i l 'I 20 21 22 23 24 25 26 27 28 Scale rows @ midbody Figure 20. Histogram of number of dorsal scale rows at mid-body for Sistrurus catenatus tergeminus (Kansas).
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Discussion
Patterns of color and the amount of ventral pigmentation are
similar between Colorado massasaugas and the desert subspecies, S.
c. edwardsi, while the western subspecies, S. c. tergeminus, exhibits a
rather different coloration and a much more pigmented ventral surface
(Table 10). Colorado snakes and S. c. edw ardsi were more often gray as
the ground color, while S. c. tergeminus were brown and light brown,
which is a current diagnostic ground color for this subspecies (Conant
and Collins, 1991). Body blotch colorations for S. c. tergeminus were
mostly brown (25/29), while Colorado snakes and S. c. edwardsi were variable for blotch color, from olive brown, brown, dark brown to dark
gray, indicating that both subspecies are variable and this character is
not a consistent diagnostic feature. All three subspecies exhibit
similar colors for the ventral surface, although average percent ventral
surface colored for Colorado snakes (19%) and S. c. edwardsi (13%) was
much lower than the value for S. c. tergeminus (43%).
Results of the coloration characteristics for the three subspecies
clustered Colorado snakes and S. c. edwardsi, separated from S. c.
tergeminus. Based on a limited number of samples, Gloyd (1955) described the ventral surface coloration for S. c. edw ardsi as “white or cream, immaculate or sparsely flecked with gray or brown.” Conant and
Collins (1991) described the ventral surface as “nearly white and virtually (or completely) unmarked.” This description for S. c. edwardsi
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is inaccurate. Results (Table 10) showed that the majority of the
snakes examined which were classified as edw ardsi (New Mexico and
Arizona), have more dark color on the ventral surface, and the
arrangement of that color is usually located laterally and occasionally randomly.
Results of morphometric comparisons suggest that Colorado snakes
and S. c. edw ardsi are very similar for scutullation characteristics (Table 11). Sistrurus c. tergeminus differed from Colorado snakes and S.
c. edw ardsi for dorsal scale rows at one headlength posterior to the
jaw, at mid-body, directly anterior to the anus, mid-tail and number of
ventrals. Several of these diagnostic characters, also used by Conant
and Collins (1991) for differentiating S. a edw ardsi from S. a
tergeminus, indicate that snakes from Colorado belong grouped with S. c. edwardsi, and not as an intergrade between the two. These
diagnostic characteristics, which were also used by Gloyd (1955),
Klauber (1972), Conant and Collins (1991) and Maslin (1965) for defining subspecies of Sistrurus catenatus, strongly support this
conclusion. Results for other characters were more variable, suggesting that variable characters are uninformative and should be
avoided as diagnostic features of a subspecies. Conant and Collins (1991) reported the maximum length for S. c. edwardsi as 53 cm (530 mm), while the length record for S. c. tergeminus
was reported as 88.3 cm (830 mm). The known length record (SVL/TL)
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for the massasauga from Colorado is 475/54 mm (this study, Table 11), this is almost equal to the record for S. c. edwardsi. The small size of
the Colorado snakes helps facilitate movement through burrows used by small rodents (prey).
Gloyd (1955) reviewed S. catenatus of the southwest and
distinguished edwardsi from tergeminus in having a paler coloration, 23
scale rows at midbody, lower number of ventrals and lower number of
dorsal blotches. This description also fits the Colorado snakes except
for body blotch number, which is slightly higher than S. c. edw ardsi but
lower than S. c. tergeminus, consistent with Maslin’s investigations
(1965). Body blotch number should not be used because it is quite
variable among all subspecies and is therefore taxonomically
uninformative.
Results of Student’s t-tests for morphometric data showed that
Colorado snakes were morphologically similar to S. c. edwardsi, but
there were statistically significant differences between some
characters (Table 12). Significant similarities (P>0.05) exist between
Colorado snakes and S. c. edw ardsi for the following characters: dorsal
scale rows immediately anterior to the anus and at mid-tail, ventrals, right supralabials and left oculars. Maslin (1965) included ventrals and
dorsal scale rows immediately anterior to the anus as a useful
character to “differentiate between the three races of catenatus ”
Additionally, as mentioned above, Colorado snakes resemble S. c.
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edw ardsi in the number of dorsal scale rows one headlength posterior
from the jaw, at mid-body, and its smaller adult size (see Chapter 2
and Table 11, this chapter). These results indicate that massasaugas
from Colorado should be assigned to the subspecies 5. c. edw ardsi on
the basis of ground color and ventral pigmentation, size, number of
dorsal scale rows one headlength posterior from the jaw, at mid-body, directly anterior to the anus and at mid-tail. Similar diagnostic
characters also include number of ventral scales. Further support for
this conclusion comes from similarities in soil and habitat type,
activity patterns and diets of Colorado snakes and S. c. edw ardsi which
differ significantly from those of S. c. tergeminus (see Chapter 2).
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CONCLUSION
Sistrurus catenatus in Colorado is a high plains, arid grassland
species that occurs in 11 southeastern counties. The range of the
massasauga in Colorado is discontinuous from the neighboring races,
the western massasauga, S. c. tergeminus, to the east, and the desert massasauga, S. c. edwardsi, to the south and west.
The massasauga in Colorado is locally common in a few areas and
uncommon in others for reasons which remain unclear. Survey efforts at some of these areas of suitable habitat were appropriate to
determine massasauga occurrence; however, infrequent encounters
with massasaugas at these areas suggest than some populations are
of very low density and possibly imperiled. In areas where the
massasauga is common, native vegetation and an abundant prey base are common features. Morphological divergence due to geographic isolation over time is
probably responsible for the present morphological variations seen within the Sistrurus catenatus complex. Habitat characteristics of
Colorado snakes and other S. c. edwardsi are very similar. In Arizona,
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the massasauga inhabits dry, intermontane valleys consisting of
grasslands [Hilaria mutica) with yucca and mesquite scattered sparsely
at an elevation around 4500 feet (Mendelson and Jennings, 1992; A.
Holycross, pers. comm.)- In New Mexico, the massasauga is an
inhabitant of the desert grasslands or short-grass prairie with sandy
soil, avoiding rocky habitat (Degenhardt, 1996). These habitat
descriptions are essentially identical with those of Colorado snakes.
Results show that for S. c. edw ardsi and Colorado snakes, there is an
affinity for the same type of soil, Aridisols, while in the east, dominant
soil types in the range of the massasauga are Alfisols and Mollisols
(Epsenshade, 1990). Because of the terrestrial nature of these snakes,
soil type may be informative about possible edaphic restrictions and
should be investigated.
Mountain ranges form rainshadows that influence the amount of
the moisture available for the grasslands that occur to the east of the
mountains, and rainshadows exist for all populations of 5. c. edwardsi
and for Colorado snakes. In comparison, a population of Sistrurus c. tergeminus in Kansas inhabits lowland, boggy, wetland plains along the
Arkansas River drainage, far removed from this rainshadow effect. This
trend in habitat affinity continues eastward, including populations in
Missouri (Seigel, 1986), Wisconsin (Keenlyne, 1968) and Illinois
(Wright, 1941). In the east, S. c. catenatus in Pennsylvania (Reinert
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and Kodrich, 1982) and Ontario, Canada (Weatherhead and Prior, 1992) also inhabit moist, lowland swamps.
A dry climate is associated with all populations of S. c. edw ardsi
and is also the case for Colorado snakes, which inhabit areas with an
average annual rainfall of 35 cm (McGinnies et al., 1991). In central
Illinois (Champaign), 100+ cm of rainfall annually is typical. In the
east (Toledo, Ohio) rainfall can amount to 150 cm annually. Variability in amount of rainfall is more prevalent in the west than in the east
(Espenshade, 1990).
Trends are similar in seasonal movement for Colorado snakes, S. c.
tergeminus and S. c. catenatus; seasonal movement for S. c. edw ardsi is
currently under investigation (A. Holycross, pers. comm.). Spring and
fall movement from short-grass prairie associated with loamy soils to a more sandy loam, prey abundant area for the summer (Colorado
snakes) is similar to the pattern for S. c. catenatus in the east
(Weatherhead and Prior, 1992; Seigel, 1986; Reinert and Kodrich, 1982) where snakes move from swampy conditions appropriate for hibernation, to an upland grassland type of habitat for summer
foraging. Massasaugas in Colorado utilize a nocturnal activity pattern during the arid summer months, as do snakes in Arizona, New Mexico
and Texas; activity patterns for S. c. catenatus and S. c. tergeminus
remain diurnal throughout the season (Reinert and Kodrich, 1982; Seigel, 1986; Weatherhead and Prior, 1992). Colorado snakes may be
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more sensitive to heat due to lack of available surface water, low
rainfall and having a larger surface area-to-volume ratio, resulting in
greater water loss. This is probably also true for other S. c. edwardsi
populations.
It is likely that the southeastern plains of Colorado, the western plains of Kansas, Oklahoma, western Texas, New Mexico and
southeastern Arizona were colonized by the same subspecies after the
retreat of the glaciers. Appropriate habitat corridors were created
during this time that assisted dispersal to present areas of suitable
habitat in the west. This is similar to hte dispersal pattern for S. c.
catenatus in the east (Schmidt, 1938; Martin and Harrell, 1957). The
eastward peninsular range of this snake was associated with a prairie
stage which occurred prior to the present forest formation in Ohio and
Pennsylvania, and it is fairly evident that changes in habitat conditions
have occurred since the massasauga colonized that region. These
changes have influenced current distribution patterns which are mostly
disjunct and fragmented (Weatherhead and Prior, 1992), and many have been extirpated.
It has been hypothesized th at S. c. catenatus and S. c. tergeminus are
clinal variants of a single subspecies (Seigel, pers. com.), while S. c.
edwardsi may be distinctive enough in distribution, habitat, size,
behavior, diet, color and scutullation to warrant separate species
designation. All of these are characteristics are known to have been
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instrumental, individually or collectively, in the speciation (and
taxonomic separation) of groups of other reptiles.
Documented morphological differences between the three
subspecies may have accumulated after species dispersal movements
northward, and subsequent isolation of populations was influenced by the retreat of the glaciers (Schmidt, 1938; Conant, 1978). In the east,
the southern range of Sistrurus catenatus closely follows the southern
extent of the Pleistocene glaciers. The range of the massasauga in the
west has no history of glaciation during the Pleistocene, although
appropriate habitat may have existed there, then which facilitated colonization. The time of retreat of the Pleistocene glaciers that
created a corridor to the east for massasauga dispersal (Prairie
Peninsula) suggests that S. c. edw ardsi may have colonized its present
range before S. c. catenatus colonized the Prairie Peninsula Corridor in
the east.
Geographic distribution and morphological characters of organisms are used to place animals into respective taxa. The subspecies status
of the massasauga in Colorado has been unclear, but based on
morphological and habitat data, massasaugas from Colorado should be considered Sistrurus catenatus edwardsi. This assignment of Colorado snakes to the desert subspecies also suggests that population
affinities lie primarily to the south rather than with the subspecies to
the east. It is not known whether this currently disjunct population in
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Colorado is due to recent human modifications or if it represents a
longer-term contraction of a formerly wide-spread desert/grassland
species. Geographic isolation and allopatric distributions have become
increasingly common as the human population expands. Natural ecological barriers for the massasauga in Colorado exist to the south
as mesas and Pinon/Juniper woodlands. To the east, natural barriers
between S. c. edwardsi and S. c. tergeminus are unclear. Extensive
surveys of western Kansas are needed to help resolve this uncertainty.
Native grasslands in the southeastern region of Colorado are
stable, but are becoming increasingly fragmented, a factor that leads to
rapid disappearances of populations as noted long ago by Pope (1926).
This is an aspect that governing agencies must confront. There are
programs which the state has initiated to help ease erosion resulting
from agricultural practices such as extensive cultivation and
overgrazing. Old-growth native perennial grasses and sand-sage are a
significant habitat requirement for the massasauga in Colorado and destruction will ultimately bring demise to these rattlesnakes.
Conservation and management of an endangered species in the United States can create public objection and economic expense, especially in a world of development of urban and recreational areas.
Developers responding to requirements of increasing human
populations are confronted with a problem if an endangered species exists at the proposed area of development. Because the massasauga
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in Colorado inhabits dry grassland areas that are of low commercial value, not wet prairies, the continued existence of the snake in
Colorado is relatively secure. Conservation easements may be
beneficial for both landowner and the snake, but these easements are based on the commercial value of the land and so purchase price may
not be attractive to land owners. In Colorado, the massasauga
tolerates moderate grazing, but large areas extensively farmed and/or
grazed do not support massasauga populations. Because of their small
size, cryptic color and unaggressive nature, these snakes are less
likely to be directly noticed and persecuted by humans than the larger, more aggressive prairie rattlesnake (Crotalus viridis). The highest
density of massasaugas in the state occurs on land owned by
individuals with a respect and appreciation for the massasauga. Management practices should begin with placing value on the
importance of the massasauga, ecologically and historically. The
massasauga is important in the food webs of the Great Plains as both
a predator and as prey. There is a staggering amount of the Great
Plains that has been lost forever, and retaining the remaining plains
ecosystems that represent what once was referred to as the "Great American Desert" and the "Fields of Green Velvet" is important ecologically and for understanding past events that have shaped
American history in the west. The massasauga is of scientific interest
and value as a member of the remnant, most primitive genus of
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rattlesnakes, Sistrurus. Public awareness and appreciation for the snake can be achieved if their unique role in specific ecosystems is
delineated. Additionally, rattlesnakes are of great interest to most
people since they are unusual, unfamiliar and venomous.
The information provided by this study will help the Colorado
Division of Wildlife to understand and manage one of their species of
special concern. Recovery and protection programs may designate
specific areas for preservation, helping Colorado to maintain its diverse
herpetofauna. Plans for protection of the massasauga in Colorado
should include public education programs, as these small rattlesnakes, like most snakes, are usually killed on sight. Hopefully someday
people will be proud when they know the massasauga lives on their
property. The massasauga in Colorado is a unique animal and an
indicator of healthy short-grass prairie, and it deserves concerted
conservation efforts to ensure its continued existence.
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Greene, H. W., and G. O. Oliver, Jr. 1965. Notes on the natural history of the western massasauga. Herpetologica. 21:225-228. Hammerson, G. A. 1986. Amphibians and Reptiles in Colorado, 2nd print, Colorado Division of Wildlife Publication Number DOW-M- 1-3-86. 131pp.
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APPENDICES
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Explanation of Tables
-Some specimens examined have missing characters because of poor quality/ damage.
Abbreviations:
Number: Identification number assigned to that individual snake, either a field number or museum catalog number. Colorado snakes: “A” “B” and “C” followed by a number refers to field crew identification and specimen number. “SM” represents Steve Mackessy personal specimen number. “UCM” refers to accession number for the Museum at the University of Colorado, Boulder, Colorado, USA. Curator: Rosanne Humphrey.
S. catenatus edwardsi snakes: “95” followed by a number denotes year snake collected and specimen number (Andrew T. Holycross). “ASU” refers to accession number for the museum at Arizona State University, Tempe, Arizona, USA. “UNM” refers to accession number for the Museum of Southwestern Biology at the University of New Mexico, Albuquerque, New Mexico, USA. Assistant Curator of Herpetology: Don Sias.
S. catenatus tergeminus snakes: “Chey. Bot.” refers to live specimen from Cheyenne Bottoms National Wildlife Refuge, Barton County, Kansas, USA. “N” refers to neonate snake bom in captivity. “KU” refers to accession number for the Museum of Natural History, University of Kansas, Lawrence, Kansas, USA. Curator: John Simmons. Tag Number: PIT (Passive Integrative Transponder) tag number indicated by either AVID Inc. reader or Biosonic. DOR=found dead on the road; AOR=found alive on the road. Sex: Gender of that individual (l=male; 2=female).
Age: Age class of th at individual (l=adult; 2=juvenile/neonate).
Date: Date when individual was found in the field.
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Time: Time of day individual was captured (applies to snakes found alive only).
Temperature: Temperature at moment when individual was captured (applies to snakes found alive only).
County: County in which snake was found (Colorado snakes). l=Lincoln 2=Kiowa 3=Crowley 4=Cheyenne 5=E1 Paso 6=Pueblo 7=Otero 8 =Bent 9=Prowers 10=Las Animas ll=B aca
Dorsal scale rows: one headlength from jaw: one headlength posterior from rictus of jaw. mid-body: mid point of total length. directly anterior to the anus: minimum number of dorsal scale rows. mid-tail: mid point of tail.
Ventrals: scales from anus (not including anal plate) to last scale wider than long, usually under neck.
Caudals: number of scales on ventral surface of tail; split scales were counted as a single scale.
R s-labials: scales on upper-right lip.
L s-labials: scales on upper-left lip. R i-labials: scales on lower-right lip. L i-labials: scales on lower-left lip.
R oculars: scales surrounding right eye. L oculars: scales surrounding left eye.
Blotches: number of body blotches from neck to anal plate.
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Tail ring: number of bands between last blotch (opposite anus) and basal rattle.
Head w.: width (mm) between snout and midpoint between jaw articulations.
Head 1.: length (mm) between points of jaw articulations.
SVL: length (mm) between snout and vent (anus).
TL: length (mm) between vent and basal rattle fringe scales.
Total 1.: total length of snake (mm). Wt.: weight of snake (g).
TL/ SVL: ratio for tail length to snout-vent length.
Rattle seg.: ^incomplete set; C=complete set; number of rattle segm ents
Lyre: l=discontinuous lyreform on right side; 2=discontinuous lyreform on left side; 0=intact lyreform.
Ground color: l=gray 2=gray/brown 3=light gray 4=brown 5=dark gray 6=light brown
Blotch color: 1=light brown 2=brown 3=dark brown 4=dark gray
Belly color: l=dark brown 2=brown 3=gray 4=dark gray 5=white
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% belly colored: estimation of amount ventral surface area darkly colored.
Belly color arrangement: l=peripheral: dark marks placed laterally 2=intermediate: combination of peripheral and random 3=random: dark marks randomly placed
Location: Range, Township, Section and quarter section as location of individual.
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Appendix A
Identifications, morphometric data and locations of Sistrurus catenatus from Colorado
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 118 • • • 147 139 144 147 142 146 140 147 141 142 143 145 147 145 140 144 147 141 145 148 141 V entral 9 140 8 11 10 13 149 9 11 153 12 10 150 11 13 11 U Mid tail 17 17 19 19 19 18 11 18 10 15 10 150 15 19 12 19 12 1819 18 11 10 146 17 17 a n u s 23 18 11 23 23 18 11 22 2523 19 19 12 24 25 23 23 16 11 146 23 23 20 11 25 19 23 23 19 10 from Colorado Midbody A nt # # Dorsal scale rows • • 22 23 22 23 21 23 23 23 23 23 18 12 23 23 19 22 21 22 23 23 20 23 22 22 23 23 from jaw 1 1 I 1 1 23 25 1 23 23 1 23 1 1 23 1 1 1 1 1 23 23 1 1 1 1 1 20 23 1 1 23 25 13 11 146 5 2 23 Sistrurus catenatus • • • • • #•• • • • 21 1 27 21 24 1 22 23 19 11 24 1 25 23 19 12 21 21 21 21 21 2121 1 1 23 23 23 23 19 19 11 27 I 20 27 27 24 26 Temperature County 1 head length 16:45 12:20 11:30 23 15:15 11:30 23 1 23 23 19 10 146 15:00 15:00 15:00 15:00 15:00 21 1 23 23 18 11 12:00 30 22:10 20:00 00:24 24 21:00 D ate Tim e 1 0 /8 /9 5 1 0 /8 /9 5 1 0 /7 /9 5 1 0 /7 /9 5 8 /8 /9 5 1 0 /3 /9 5 1 0 /3 /9 5 9 /1 /9 5 9/26/95 15:009 /2 6 /9 5 9 /2 6 /9 5 9 /2 6 /9 5 9/26/959 /2 6 /9 5 15:00 6 /2 0 /9 5 1 1 1 1 1 1 1 1 9/26/95 15:00 2 1 1 1 1 2 1 1 0 /1 /9 5 2 1 9 /2 6 /9 5 1 1 1 8 /1 8 /9 5 1 1 1 8 /1 5 /9 5 2 2 1 1 1 1 1 7 /2 1 /9 5 2 1 6 /1 8 /9 5 2 1 DOR 1 1 DOR DOR 224225F59 224233137F 1 1 10/8/95 11:55 2242295C 11 22423D721A 22421E4114 2242286729 2 1 224234237D 22421B2342 22423F2808 22421A066C 2 1 9/15/95 19:00 2242217596F A-1299 A-1295 DOR 1 1 A-1287A -1294 224221655E 2 1 10/8/95 14:05 A-1276A-1282 22423A6338 2 1 A-1272 2242172703 2 1 A-1270 A-1273 DOR 2 1 9 /2 6 /9 5 A-1271 A-1262 2242295F06 1 1 9/26/95 A-1263 DOR 1 1 A-1259 22421B5A23 A-1258 A-1260 A-1261 A-1255A-1256 A-1257 224215082C A-1253 A-1254 A-1243 TAG AOR, NO 1 2 9/23/95 14:10 A-1193 22421E6D4B 1 1 9/1/95 A-1072 A-0625 A-0959 2242322A73 1 1 A-1190 224231746F 1 1 A-0958A-1035 22421B2176 1 DOR 1 8/7/95 23;00 A-0493 DOR 2 1 7 /1 4 /9 5 A-0345 DOR A-0404 22421E6E5C 1 1 7/10/95 Number Tag number Sex Age A-0019 DOR 1 1 5 /2 2 /9 5 Table 13. Identifications, morphometric data, and locations of
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 119 145 142 141 144 141 150 144 148 142 150 151 145 142 144 153 151 142 147 144 137 141 147 150 143 140 9 9 142 10 11 145 12 11 148 12 144 12 9 141 12 9 11 146 13 9 10 10 10 12 12 11 10 11 Mid tail Ventral 18 19 12 18 19 18 19 18 11 146 17 18 19 16 10 17 19 17 17 9 18 10 145 18 18 19 19 19 18 11 19 23 23 20 23 25 23 23 24 23 23 23 23 21 17 23 23 23 18 10 149 23 23 23 23 23 18 25 # Dorsal scale rows • 23 23 18 8 23 23 2525 25 20 12 150 2323 25 23 23 22 23 22 22 23 18 10 25 25 23 2323 23 23 18 16 10 20 23 23 18 23 23 22 23 23 23 23 23 23 23 19 11 23 23 18 10 from iaw anus 1 1 head length Midbody Ant \ \ \ • • • 2 2 2 • | • 2 • • | • • • J • • J • J 21 1 24 1 21 1 22 26 1 21 1 23 21 1 22 21 I 1 24 22 22 1 1 22 1 22 1 22 1 21 21 1 1 23 23 21 1 10:40 21 1 23 23 10:50 10:00 20 1 19:15 21 1 23 15:15 15:40 26 1 13:10 14:45 22:20 20:45 14:20 22 1 14:30 13:52 13:17 21 1 23 12:05 21 I Time Temperature County 4 /2 3 /9 6 4 /2 4 /9 6 4 /2 3 /9 6 4 /2 5 /9 6 4 /2 4 /9 6 4 /1 3 /9 6 1 0 /8 /9 5 1 0 /8 /9 5 10/8/95 14:30 1 0 /8 /9 5 10/8/951 0 /8 /9 5 14:48 10/8/95 14:45 1 0 /8 /9 5 10/8/95 13:48 1 0 /1 5 /9 5 1 0 /1 4 /9 5 1 0 /1 4 /9 5 1 0 /1 0 /9 5 1 1 1 4 /2 3 /9 6 1 1 1 4 /2 5 /9 6 1 1 1 1 1 1 4 /2 4 /9 6 2 1 1 1 1 4 /1 3 /9 6 1 1 1 1 1 9 /1 /9 5 9 /1 /9 5 1 1 1 9 /1 /9 5 2 1 1 1 1 1 1 1 10/8/95 13:00 1 1 2 1 1 1 1 0 /8 /9 5 1 1 1 2 1 1 1 1 1 0 /8 /9 5 1 1 1 10/8/95 12:10 1 1 1 1 0 /8 /9 5 2 1 2 1 2 1 DOR DOR DOR 1 2 DOR 2 2 DOR DOR 4145495909 414557374B 1 1 41452C1D04 22421F472E 2 1 10/8/95 22421748322242335528 2 1 AOR, AOR, TAG NO TAGAOR, NO 2 2 1 0 /8 /9 5 13:00 224221213D 2242285P12 224213115C 2242227553 A-1352 A-1353 A-1350 A-1351 4145517759 A-1348 DOR 1 1 A-1349 DOR A-1346 DOR A-1344A-1347 DOR • DOR 2 1 A-1345 A-1343 A-1341 22422C610B A-1342 2242191358 A-1323A-1330 A-1336 22421C2B7B A-1328 A-1322 2242292D36 2 1 10/10/95 A-1315 A-1316 A-1313 A-1314 A-1311A-1312 2242235A1E 22422556ED03 1 1 10/8/95 14:45 A-1309 Number Tag number Sex Age Date A-1310 AOR, TAG NO 2 1 A-1306A-1307 2242345474 DOR 2 1 A-1305 A-1308 22422B4D2B 1 1 A-1303 A-1304 2242136ED13 A-1300 A-1301 A-1302
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. • • • 141 144 149 142 142 144 154 147 150 141 147 141 143 151 147 146 143 144 148 •• • • 9 8 13 11 10 145 12 10 151 11 9 10 145 11 11 148 11 140 10 13 11 10 1112 145 Mid tail Ventral • 19 19 17 19 11 18 11 19 18 11 146 19 19 19 19 20 10 18 19 18 11 145 20 10 148 •• ••• 24 23 19 23 23 24 23 23 18 11 23 23 19 23 23 17 4 D orsal scale rows • • 25 23 19 11 146 23 2324 25 18 10 140 23 23 23 23 23 23 23 19 2323 23 23 23 23 19 23 23 17 23 23 19 23 21 23 23 from iaw anus 1 1 head length Midbody Ant I 1 23 1 23 23 19 11 145 1 1 25 23 19 1 25 1 25 23 1 1 23 1 1 1 1 1 1 23 23 1 23 1 1 23 I 1 23 23 19 12 1 •• o • • • • • • • • • 26 1 23 23 22 1 23 22 2121 22 1 22 24 24 22 1 22 1 21 21 22 1 22 23 Temperature County 22:32 21 1 10:00 11:00 20:15 16:00 12:00 21 1 22 23 11:00 T im e D ate 7 /5 /9 6 6 /2 7 /9 6 6 /1 9 /9 6 4/26/96 11:40 4 /2 5 /9 6 4/26/96 11:00 4 /2 6 /9 6 4/25/9616:00 24 1 23 25 18 4 /2 6 /9 6 4 /2 5 /9 6 4/25/9615:004/25/96 15:00 22 22 1 23 23 17 4/25/96 15:00 4 /2 5 /9 6 4 /2 4 /9 6 4/24/9612:00 22 1 23 23 18 9 1 1 1 7 /1 /9 6 • • | 1 1 1 7 /1 /9 6 1 1 1 1 1 1 4 /2 8 /9 6 1 1 1 1 2 5 /2 9 /9 6 5/29/96 19:00 16 1 1 1 4 /2 5 /9 6 1 1 1 4 /2 8 /9 6 1 1 1 1 1 1 2 1 5 /3 0 /9 6 2 1 5 /2 3 /9 6 1 1 1 4/25/96 16:00 1 1 1 4/25/96 19:00 1 1 1 4/25/96 15:00 2 1 1 1 1 4/25/96 15:00 22 2 1 4/26/96 10:00 2 1 2 1 2 1 DOR DOR DOR 1 1 DOR DOR DOR DOR DOR DOR 2.24E+79 2 1 4145315944 4145486D7A 1 1 6/21/96 21:15 22 41453C2767 4145406C0E 4145355D52 4145406F19 2 1 22421A4A49 2242384168 2242131F34 1 1 2242376254 22421B1E40 2242340P22 2 1 22423B6502 1 1 4/24/96 10:00 41454B3548 2 1 4145490766 1 1 4/24/96 13:00 22421B1B79 A-2682 A-2510 A-2512 A-2328 A-2467 A-2301 A-1496 A-1533A-1534 A-1539 DOR DOR A-1386 A-1387 A-1380 A-1378 A-1379 DOR 1 1 4 /2 5 /9 6 A-1373 A-1370 414530073F A-1372 A-1369A-1371 414539754C A -1368 A-1366A-1367 2242127528 2 1 A-1365 224235724D A-1363 A-1364 A-1362 A-1359 Number Tag number Sex Age A-1360 A-1361 A-1357 A-1358 22423E1213 1 1 4/25/96 12:00 21 A-1356 4145352029 2 1 A-1355 A-1354
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 121 • • • • • • 148 145 144 146 143 145 140 144 145 143 144 144 145 143 150 144 148 V entral •• • 10 11 145 11 12 12 12 11 146 11 11 1111 144 10 143 12 11 143 10 11 13 12 145 11 Mid tail • • • • •• 18 19 11 •• 19 19 18 19 18 18 19 19 19 10 19 18 11 18 11 143 20 11 145 19 19 19 17 18 • •••• 23 19 11 146 21 23 23 23 21 19 25 23 23 23 23 18 23 # # Dorsal scale rows •••• »• • •••• •• • • •• • 23 23 23 23 24 24 2523 23 23 18 11 23 23 23 23 23 16 11 23 23 23 25 23 23 23 23 25 from jaw anus 1 1 head length Midbody Ant I 23 23 1 23 1 1 1 23 23 1 1 1 1 1 25 25 1 1 23 23 1 25 1 1 3 23 23 2 2 1 2 23 1 1 1 4 1 3 2 3 1 23 • • • m • • • • • • • • • • • • • 18 27 27 21 21 21 20 18 16 2 20 1 19 16 2 20 24 Temperature County 17:00 16:50 16:40 18:40 20:24 20 1 25 23 18 10 148 20:22 21 22:00 22:19 20:35 21:17 22:26 21:10 21:06 20:46 18:00 20:57 Tim e 20:37 9 /1 /9 6 9/1/96 20:15 8 /8 /9 6 8 /7 /9 6 8 /6 /9 6 8 /3 /9 6 8 /3 /9 6 8 /3 0 /9 6 7 /8 /9 6 9 /1 4 /9 6 8/30/96 20:02 15 I 8 /2 0 /9 6 8 /2 0 /9 6 8 /1 2 /9 6 7/24/96 20:56 7 /2 8 /9 6 1 9 /6 /9 6 1 1 1 1 9 /2 8 /9 6 1 1 1 9 /2 8 /9 6 1 1 1 9 /1 4 /9 6 1 1 1 1 1 1 1 1 1 1 8/8/9622:05 1 8 /2 0 /9 6 18 1 23 23 2 2 1 1 1 1 1 1 1 8 /2 0 /9 6 2 1 1 1 1 8 /6 /9 6 • • 1 1 1 1 1 1 7/31/96 20:30 2 1 2 1 DOR DOR 1 1 DOR 1 1 9 /1 /9 6 DOR 1 1 8 /2 0 /9 6 DOR 1 1 DOR 2 1 DOR DOR DOR 1 8 /2 /9 6 DOR 1 1 8 /2 /9 6 DOR DOR DOR 1 1 7 /2 4 /9 6 11365864 23117119 41454B784E 4145544D4E 41453E5704 41452B5249 1 1 9/1/96 20:12 41452B7838 4145471607 1 1 8/8/96 41454C5B25 A-3170 A-3171 23892283 A-3155 A-3150 A-3159 A-3149 DOR A-3142 A-3139 A-3140 A-3138 A-3097A-3122 DOR 2 1 8 /2 0 /9 6 A-3094 DOR A-3096 A-3031 A-3033 A-3046A-3090 DOR DOR 1 1 A-3093 414549214B A-3095 A-3028 A-3001 A-2988 A-2991 DOR 1 A-2968 A-2969 DOR A-2948 414544405D 1 1 8/2/96 A-2956 A-2955 A-2878 A-2944 414546403A A-2835 Number Tag number Sex Age Date A-2726A-2833 41454D301A 1 1 7/8/96 23:35 A-2717 41453F1901
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 122 • 146 146 145 144 141 146 149 145 142 146 145 143 145 146 142 145 148 145 146 141 148 145 144 V entral •• •• 9 • • 10 145 12 11 11 13 10 145 • 10 11 142 11 11 11 1110 137 11 10 10 10 Mid tail ••• • ••• ••• •• 19 19 12 19 19 •• • •• 19 18 19 17 12 144 19 19 19 11 151 19 19 12 18 19 19 19 19 19 21 • •••• • 23 23 23 2323 20 11 23 25 23 23 23 23 23 24 23 25 23 23 18 23 18 25 23 # Dorsal scale rows •• • • • ••• • • 23 23 24 23 23 23 24 23 23 18 24 24 22 from jaw anus 1 1 head length Midbody Ant 1 23 1 1 1 25 23 1 1 23 23 1 1 1 1 11 23 23 23 2 2 3 23 23 9 2 23 23 1 25 23 3 1 23 23 1 1 23 1 23 1 23 1 • • • # • • • • • • • • • • 21 21 21 24 I 24 22 I 21 21 21 24 24 1 23 24 1 22 27 Temperature County 19:57 24 1 25 23 19:55 19:58 19:54 21 19:40 20:15 20:21 21 1 23 23 10:20 22 10:15 10:15 17:30 10:15 10:05 16:50 10:00 9 /4 /9 6 9 /3 /9 6 9 /3 /9 6 9 /3 /9 6 8 /2 /9 6 9 /1 2 /9 6 1 0 /5 /9 6 1 0 /6 /9 6 1 0 /5 /9 6 9/29/96 10:10 24 l 9 /2 8 /9 6 1 9 /3 /9 6 1 1 8 /2 2 /9 6 1 7 /2 9 /9 6 1 8 /2 1 /9 6 1 7 /3 /9 6 1 1 4 /2 6 /9 6 1 2 10/6/96 10:20 2 1 0 /6 /9 6 2 2 2 9/29/96 10:00 24 2 2 9/28/96 16:54 27 1 23 1 • • • 1 1 9 /2 /9 6 • 1 2 1 9 /3 /9 6 2 1 1 1 1 9 /2 8 /9 6 2 1 1 7/15/96 20:43 22 1 1 2 1 1 2 2 1 2 2 2 1 0 /6 /9 6 2 DOR DOR DOR 2 1 7 /1 6 /9 6 DOR DOR 10875335 2 1 9/9/96 19:43 24320344 25264800 1 23867024 25621272 41452A014D 2 1 4145314671 414553773E 2 1 41452C2232 4145531744 AOR, TAGAOR, NO 2 2 9 /2 9 /9 6 Tag number Sex Age Date Time AOR, AOR, TAG NO AOR, AOR, TAGNO 1 2 9 /2 9 /9 6 AOR, AOR, TAG NO C-043 C-020 414550557A 1 1 C-021 4145534577 B-819 C-018 4143F4906 1 1 B-762 C-015 C-016 11276587 B-702B-761B-774 2242355B2B DOR 1 DOR 1 9/9/96 2 1 9 /1 0 /9 6 B-547 B-559 DOR B-300 B-415 DOR B-266 DOR 1 A-3211 A-3212 DOR A-3205 A-3210 A-3203 A-3197A-3204 24839894 A-3196 A-3202 A-3195 A-3187 A-3194 A-3183A-3192 TAG AOR, NO 23126114 A-3184 A-3181 N um ber A-3172 TAG AOR, NO A-3182 AOR, TAGNO 2 2 9/29/96 A-3173
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 123 • 143 140 146 151 147 142 145 144 141 145 143 147 146 142 144 146 142 11 159 1111 152 143 11 145 10 11 11 148 11 146 10 11 11 11 11 9 145 1111 149 148 9 11 144 1110 147 11 140 11 11 11 11 13 146 10 143 Mid tail Ventral • • • 17 19 18 12 1919 11 19 19 19 19 181818 10 11 149 19 17 1919 11 12 19 19 19 19 19 17 17 19 17 19 19 17 •••• • • 23 24 19 23 25 23 23 25 25 23 # Dorsal scale rows 0 • • 23 2323 23 23 23 23 22 25 23 23 18 25 24 24 2323 23 23 25 25 23 23 from jaw anus 1 1 head length Midbody Ant 1 1 23 23 1 23 25 1 25 25 1 23 23 1 23 23 1 23 23 I 23 25 18 11 145 4 1 1 1 4 1 23 23 I 23 1 22 1 1 1 1 I1 23 23 21 21 C ounty • • • •• • 21 23 1 24 21 1 23 23 24 24 21 22 1 23 23 24 24 21 21 22 1 25 23 22 1 22 I 22 22 1 24 19:51 19:40 19:45 19:37 24 19:46 20:10 21 1 23 25 20:06 22:00 20:00 23 21:01 21:15 20:14 22 19:59 24 19:57 24 20:10 20:03 20:02 Time Temperature 20:46 21 1 20:35 9/9/9620:05 23 1 23 23 9/9/96 19:53 24 9/9/969 /9 /9 6 19:39 9 /9 /9 6 9 /5 /9 6 9/5/96 20:18 22 1 9 /5 /9 6 9 /1 1 /9 6 9 /5 /9 6 9 /1 1 /9 6 9/4/96 21:07 21 9 /1 0 /9 6 9 /1 0 /9 6 9 /1 0 /9 6 9 /4 /9 6 • • • J 1 1 1 1 1 1 1 2 1 9 /1 0 /9 6 1 1 1 9/5/96 21:43 21 1 2 1 9 /1 0 /9 6 2 1 1 1 1 2 1 1 1 1 9 /5 /9 6 1 1 1 1 1 1 9/5/96 20:12 2 1 2 1 2 1 1 1 1 9 /4 /9 6 1 1 1 9 /4 /9 6 1 1 1 9/4/96 20:15 2 1 DOR DOR 1 1 9 /5 /9 6 DOR 1 1 11547374 224215790B 2242212309 2 1 9/9/96 20:27 2242387F7D 2242301B4A 4145571920 414538130C 2242239393E 41452A0828 4145430B0A 2 1 4145516B7B 4145496306 414551386B 2 1 9/4/96 Tag number Sex Age Date C -142 C-141 DOR C-126C-128 2242313C50 22421E735D 1 1 I 1 9/10/96 9/10/96 20:18 C-129 2242256A19 1 I 9/10/96 20:55 C-123C-125 224214583F 22423B5F0D C-121 C-122 2242157A1C C-120 11518576 C-105 C-104 C-108 2242205537 2 1 9/9/96 C -102 C-lOO C-101 C-093 C-099 22422F4C04 2 1 C-091 C-092 10836578 C-086 4145462163 2 1 9/5/96 C-085C-087 4145284915 C-083 4145491F5E 1 1 9/5/96 C-084 4145393969 2 1 9/5/96 C-057 C-072 DOR 1 1 9 /5 /9 6 C-082 414542592D 2 1 C-058 C-051 C-052 C-048 C-050 4145377667 C-046 41453E0414 N um ber C-045
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. L24 • • • • • • • • 144 148 144 140 146 149 141 144 147 144 148 143 144 144 151 • • 10 143 11 11 142 9 149 11 11 10 10 11 10 11 10 11 11 12 141 Mid tail Ventral •• • •• •• • ••• 17 18 18 11 18 •• 18 11 19 12 142 19 18 11 146 20 17 1919 10 11 145 20 11 145 19 19 19 11 19 11 17 18 10 • • • 23 23 24 19 23 19 25 24 23 23 19 10 151 23 25 # # Dorsal scale rows • ••••• • •• •• •••• • •• •• 24 23 25 24 23 23 19 24 24 23 23 25 23 19 11 147 2321 23 23 from jaw anus 1 1 head length Midbody Ant 1 1 23 23 1 23 1 23 23 19 1 1 22 23 19 1 1 1 1 23 23 1 1 23 1 1 1 23 1 2 11 23 25 25 25 22 23 1 23 23 2 23 23 3 2 4 4 4 4 4 4 C ounty • • • • • • • • • • • • • • • • • • • • 27 21 27 18 1 22 23 19 17 24 26 2 20 21 4 Temperature 13:30 21:00 15:59 19:27 21:52 20:02 21 9 /3 /9 4 1 0 /9 /9 6 1 0 /6 /9 6 1 0 /7 /9 6 1 0 /7 /9 6 1 0 /7 /9 6 7 /1 4 /9 4 1 0 /5 /9 6 1 0 /7 /9 6 1 0 /3 /9 6 9 /2 3 /9 6 9 /2 1 /9 6 9 /1 7 /9 6 9/18/96 13:00 9 /1 2 /9 6 9 /1 2 /9 6 9/12/9621:56 18 1 23 23 9 /1 2 /9 6 9/11/96 21:58 20 9 /1 1 /9 6 1 2 1 1 9 /1 7 /9 6 2 1 1 1 1 1 9/3/94 13:30 1 1 1 10/10/96 1 1 1 1 2 1 1 1 1 0 /7 /9 6 1 1 1 1 1 2 2 1 2 2 10/11/96 10:30 1 1 1 1 0 /7 /9 6 1 1 2 1 1 1 1 0 /2 /9 6 2 1 1 0 /7 /9 6 1 1 1 1 1 9/21/96 9 /2 3 /9 6 19:30 18 2 1 10/3/96 17:20 1 1 1 9 /1 6 /9 6 20:25 14 1 1 1 1 1 1 9 /1 1 /9 6 2 1 DOR DOR DOR DOR DOR DOR DOR DOR DOR DOR DOR DOR DOR DOR DOR DOR DOR DOR DOR DOR DOR 11532363 10875051 1 1 24022264 25830306 1 1 10/3/96 16:13 26 11285113 1 1 10875347 24020052 2 1 25091048 2 1 255528364 22422E2F7D 1 1 9/11/96 20:20 SM SM 676 SM SM 675 11324597 C-367 SM 653 C-360 C-345 C-352 C-363 C-343 C-344 C-339 C-342 C-338 C-304 C-337 C-294 C-297 C-275 C-293 C-233 C-230 C-220 C-209 C-216C-221 25531872 25093260 2 1 C-184 C-207 C-189 C-176 C-177 C-162 C-158 Number Tag number Sex Age Date Time C-151 C-157 C-148 22422F5943 2 I
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 125 • 147 152 140 146 147 146 147 143 139 147 144 148 148 140 149 143 147 146 147 V entral 12 10 146 12 11 9 11 9 10 145 11 143 10 10 11 11 11 10 12 10 Mid tail • • 18 10 19 12 1918 12 19 20 11 148 19 19 17 19 17 19 19 17 18 23 24 25 24 23 19 11 23 23 23 23 25 24 19 23 23 # # Dorsal scale rows • • • 23 23 18 12 23 23 23 23 23 23 23 18 9 23 22 23 23 23 18 10 148 24 25 25 25 25 22 from jaw anus 1 1 head length Midbody Ant 1 1 23 23 20 11 1 23 1 23 3 23 23 1 3 1 3 23 7 1 1 1 23 1 23 23 18 4 3 23 23 1 1 23 23 4 3 2 10 2 2 2 C ounty • • • • • • • • • • • • • • • • • • • • • • 21 26 Temperature 16:35 7 /1 /7 0 9 /4 /9 4 9 /3 /9 4 9/3/94 20:55 9 /3 /9 4 6 /3 0 /9 1 6 /2 9 /9 1 6 /1 8 /7 9 5 /1 7 /5 7 5 /2 3 /6 4 7 /1 5 /6 1 1 1 /2 8 /7 9 9 /1 9 /9 4 9/19/94 20:15 20 9 /1 5 /9 4 1 I 1 0 /1 /8 8 1 1 1 1 1 1 1 2 1 1 5 /2 7 /9 5 1 1 1 1 1 1 I 1 4 /2 7 /7 0 1 1 1 I 4 /8 /6 5 1 1 2 2 2 2 2 9 /3 /9 4 Sex Age Date Time DOR 1 1 6 /9 /9 5 DOR 1 6 /9 /9 5 DOR 1 DOR I DOR 1 1 6 /2 4 /9 5 DOR 1 DOR 10839022 10360608 Tag n u m b er AOR, AOR, TAG NO UCM-57337 UCM-56463 UCM-56464 UCM-52174 UCM-56216 UCM-52026 UCM-52027 6/18/79 UCM-25642UCM-42250 UCM-42373 1 1 UCM-19973 1 UCM-25625 UCM-19754 UCM-19755 1 1 7/30/61 SM SM 793 SM SM 791 SM SM 702 SM 716 SM SM 784 SM SM 687 SM 690 SM 695 SM SM 679 SM 681 N um ber SM SM 678 DOR
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 126 • • 400 411 329 388 389 367 368 444 395 389 363 327 420 356 375 390 • • 32 • • 50 355 45 332 39 371 380 45 425 351 37 332 42 374 340 49 175 20 195 335 33 403 50 453 350 33 383 330 28 358 353 36 322 41 374 46 475 54 529 325 31 295 32 335 31 366 315 36 351 344 31 346 44 SVL TL Total 1. • • 14 12 370 32 402 14 12 380 31 9 • 12 14 350 52 402 10 335 32 15 395 49 14 13 13 362 33 16 14 13 14 •• • • 19 11 •• 18 13 290 39 • 23 1918 13 11 315 40 355 19 13 365 34 399 21 13 21 18 12 20 2122 11 335 31 366 20 22 1915 11 1819 10 12 2124 12 360 32 392 22 27 21 21 14 Head 1. Head w. 8 6 7 21 13 370 38 408 9 5 8 4 6 7 8 6 8 8 6 6 8 8 7 5 6 9 5 22 7 9 19 ring 37 37 39 6 38 33 37 38 41 39 8 20 36 35 1041 23 47 42 39 36 37 38 34 37 41 38 5 33 38 6 8 7 7 44 7 7 7 7 8 40 8 8 8 8 36 6 • 8 m 8 38 6 20 7 8 8 7 7 7 a •• •• 8 7 7 9 9 7 8 8 7 7 • 8 8 8 38 6 8 7 7 8 8 8 8 8 8 • 11 8 11 8 8 33 11 8 12 12 10 11 10 11 12 12 11 12 L i-labial R ocular L ocular Blotch Tail 11 11 8 8 35 8 11 11 8 8 • 12 12 11 11 10 8 8 35 11 11 11 11 11 1113 11 8 1110 12 8 8 45 11 11 12 11 12 8 13 12 11 12 R i-labial 11 •••••• 12 10 11 11 12 11 13 13 11 10 10 12 12 12 13 12 L s-labial •••• 12 12 11 10 11 12 12 13 12 8 8 336 11 11 11 11 12 12 13 13 8 8 12 11 11 11 11 11 10 11 8 12 12 11 12 11 11 10 11 11 11 12 12 11 11 11 11 12 R s-labial 30 28 12 11 27 26 23 10 11 11 11 21 23 23 11 23 25 11 11 10 28 11 28 20 28 21 2928 11 11 11 27 26 A-1301 A-1299 A-1300 A-1295 A-1276 A-1294 28 11 11 A-1287 22 A-1272 26 11 11 11 A-1282 A-1273 28 A-1271 A-1262 31 11 A-1263 23 A-1270 30 12 A-1259A-1261 25 22 12 11 A-1260 30 12 12 11 A-1255 26 11 11 A-1256 A-1257 27 A-1258 24 A-1253 25 11 A-1243 A-1254 A-1190 A-1193 A-1035 A-1072 A-0958 Number Caudal A-0959 A-0493 A-0345A-0404 A-0625 25 12 A-0019 28
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 127 505 380 380 372 317 420 403 436 407 192 355 384 325 409 412 204 383 378 387 332 360 397 406 50 32 51 442 44 32 30 401 47 28 395 19 44 36 42 44 31 20 161 43 32 29 374 36 346 32 34 35 29 349 34 404 141 395 48363 443 186 18 316 30373 346 351336 29 340 391 361 388 48 371 173 455 285 365 341 294 380 345 310 335 45 380 350 33 355 345 33 325 40 365 320 370 SVL TL Total 1. • • • • 12 11 12 1212 367 12 13 9 14 11 12 319 13 12 11 11 12 12 11 330 30 11 331 38 369 13 298 • ••• •• •• • • 18 19 20 24 21 17 17 11 7 17 2 2 . 12 19 19 22 22 22 12 362 44 2220 11 13 Head 1. Head w. 7 8 5 18 7 19 6 7 21 9 7 6 8 7 4 7 14 6 7 8 5 7 19 5 7 11 20 5 6 rinfi Tail • 38 35 838 23 37 36 8 39 38 3938 9 8 41 7 40 10 20 41 7 17 9 34 41 42 39 5 18 11 37 42 37 38 9 35 43 7 23 12 362 47 • 8 7 7 8 8 7 39 7 8 8 40 5 8 38 8 7 41 8 46 8 38 7 8 • • 7 7 7 33 7 96 8 7 7 879 8 7 40 8 33 8 7 7 34 7 7 36 6 15 9 8 8 8 7 7 8 45 88 8 8 8 7 7 7 7 8 9 R ocular L ocular Blotch • • 9 7 7 11 11 10 13 15 8 10 813 8 12 10 12 12 12 12 11 L L i-labial • 11 12 12 14 14 12 1212 12 11 11 10 10 8 8 11 10 1111 12 11 12 11 11 12 R i-labial • • 10 11 12 11 11 12 13 12 12 10 10 10 10 11 12 11 11 11 10 • 12 12 12 12 11 11 11 12 11 11 11 12 12 1210 12 11 11 11 11 11 10 11 12 12 10 11 11 11 11 11 10 11 11 11 11 12 11 11 11 11 11 11 12 12 8 11 12 11 11 7 7 12 11 12 11 11 8 11 11 10 11 8 8 R s-labial L s-labial • 18 22 10 11 11 29 22 26 11 11 12 12 29 26 23 13 12 27 29 29 12 27 21 26 22 11 11 13 26 9 28 23 32 22 2 5 28 23 27 28 29 23 C audal A-1355 A-1356 A-1353 A-1351A-1354 28 11 12 12 12 8 8 A-1350 A-1348 A-1349 A-1352 28 A-1347 A-1342 A-1344 A-1345 A-1346 A-1343 A-1341 29 11 A-1336 A-1328 31 11 12 13 13 8 9 A-1323 A-1330 A-1316 A-1322 22 A-1313 A-1315 A-1314 29 A-1312 A-1310 A-1311 A-1309 A-1307 A-1308 A-1306 N um ber A-1305 A-1303A-1304 21 28 A-1302
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 128 8 • • • • 383 368 240 412 394 404 423 384 377 431 413 396 382 384 370 418 • 40 328 40309 368 32 341 265 30 295 282 27 309 348 43 391 360 30327 41 390 380 32 472 56 528 342 41 213 27 356 48 405 • 382 41 350 44 347 30 350 34 378 35 365 31 350 32 345 39 320 35320 355 • 405 35 440 405 50 455 401 55 456 SVL TL Total 1. • • • • • • • • • • • 12 13 390 48 438 14 12 11 11 385 35 420 12 11 13 382 49 12 12 11 331 39 13 385 33 10 •• •• • • •• • • ••• • •• •• • 18 19 19 12 21 12 19 24 15 414 55 469 21 22 20 11 20 Head 1. Head w. 5 21 ••• 7 7 19 9 7 8 7 5 6 9 6 18 7 6 78 21 • 5 20 6 8 22 9 8 6 8 7 22 12 9 22 14 ring •• 3538 639 16 11 297 25 322 32 6 3732 7 38 39 42 37 37 43 9 32 37 37 34 35 6 22 41 4238 6 8 37 37 43 8 23 13 Blotch Tail 7 32 7 8 8 • • 8 77 37 39 8 8 8 7 36 8 8 40 7 • 8 • 7 7 8 8 35 7 7 8 8 7 7 7 9 8 R ocular L ocular ••• ••• • •• 12 8 12 8 8 13 8 8 11 12 9 8 12 8 8 38 12 8 11 12 10 12 7 12 8 8 L i-labial • 12 12 8 8 12 12 11 12 12 12 11 11 8 12 12 8 13 11 12 8 8 36 12 12 11 11 8 8 40 11 11 12 12 12 8 8 39 12 12 •• •• 11 11 10 11 11 12 11 11 11 10 12 11 12 1211 12 11 12 8 8 36 9 19 11 11 13 13 11 L L s-labial R i-labial ••• • • • 12 12 13 13 8 8 12 12 12 11 12 12 12 12 8 8 31 11 11 11 12 11 12 13 11 11 13 12 12 11 12 8 8 12 10 11 11 11 12 1011 11 12 12 12 13 8 8 11 10 12 11 11 11 11 12 12 6 7 12 • • 25 11 • 28 23 27 3129 12 12 29 12 11 31 28 30 23 30 28 25 28 24 23 25 11 11 31 12 24 27 12 28 27 11 A-2726A-2835 28 11 11 A-2717 A-2833 A-2512 A-2682 A-2510 26 A-2301 A-2328 A-2467 A-1534 A-1539 21 A-1386 A-1496 A-1533 A-1387 A-1379 A-1373 A-1380 A-1378 A-1370 A-1371 A-1372 24 A-1368A-1369 27 A-1366 23 12 A-1367 A-1362 Number Caudal R s-labial A-1363 A-1364 A-1365 22 12 A-1357 A-1359 27 11 A-1360A-1361 22 12 A-1358 30 10 11 11
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 129 • 361 229 204 227 353 428 332 482 371 541 515 391 475 423 •• • •• •• 18 215 19 52 449 50 418 31 375 44 384 24 25 36 35 62 42 25 220 52 55 476 58 5054 440 454 ••• • 195 197 185 317 44 344 340 420 375 35329 410 394 34 397 205 202 350 40 390 317 297 430 40 470 333 43 376 485 56 346 45 421 457 423 352 43 395 372 51 443 38 481 390 400 SVL TL Total 1. • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • t • • • • • • • • • • • • • 21 11 21 12 368 Head 1. Head w. 7 8 9 8 9 7 6 9 6 7 8 8 8 « • • 9 7 19 11 9 6 7 20 14 10 rinfi •• • • • • 37 43 36 6 36 43 6 37 37 39 9 40 32 40 44 9 34 40 8 37 35 8 26 15 37 35 37 39 35 8 35 Blotch Tail • • 8 8 40 9 • • • • • • • 8 • • •• • • • • • 8 8 7 L L ocular •• • •• 8 8 35 8 8 8 8 8 • 7 7 8 8 38 6 7 7 34 8 7 7 8 8 36 7 8 R ocular • •• •••• • ••• ••• 12 12 12 12 12 7 8 12 12 12 7 8 36 12 7 12 7 7 12 13 7 12 11 8 8 42 9 22 13 • • • • • • • • ••• •••• •••••• • • 12 12 13 12 11 7 13 12 12 12 13 13 12 12 12 11 • • • • • • 11 •••• 12 12 13 8 8 12 12 11 8 8 12 11 12 11 12 11 12 11 13 11 12 ••• •• • •• • • 12 12 12 11 11 11 13 11 12 11 11 12 1212 12 11 12 11 11 12 11 11 12 12 12 12 12 13 R s-labial L s-labial R i-labial L i-labial •• • •••••• •• ••• •• • • • • •••• •• •• 28 12 22 30 29 12 11 12 30 11 11 23 11 25 11 12 12 28 24 24 28 11 30 11 28 30 30 11 31 27 30 11 11 12 22 30 27 C audal A-3183 29 A-3182 22 A-3173 A-3181 A-3172 A-3159 A-3171 A-3170 29 A-3150 A-3155 30 A-3142 A-3149 A-3097 A-3140 29 A-3138 A-3139 A-3095A-3096 30 28 11 11 11 11 A-3122 A-3093 A-3094 A-3090 A-3046 A-3028 A-3031 A-3033 A-2991 A-2969 A-2988 A-2956 A-3001 A-2968 A-2878 A-2948 31 Num ber A-2955 A-2944
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 130 • • • 337 409 389 455 401 374 332 409 419 387 407 487 353 333 212 381 388 232 226 205 209 226 • • 37 50 34 394 37 44 374 34 34 37 33 19 44 34 45 45 41 377 37 16 208 41 22 21 20 • • ••• •• 330 360 300 372 330 30 360 405 395 50 445 342 32 345 367 376 193 385 295 342 362 346 32 378 453 321 32 336 296 189 190 15 192 340 204 211 202 24208 18 226 0 0 0 0 0 0 0 • 0 • • 0 0 0 0 0 * 0 0 0 0 12 355 33 Head w SVL TL Total 1. • • • • • • • % • •••• • •• • •••• 0 0 • • • • •• •• •• • • •• • • 23 16 44555 500 21 Head 1. 8 7 7 0 0 6 8 7 8 7 5 6 •• 5 7 7 8 20 13 36548 413 8 7 5 7 ring Tail •• •• ••• 38 8 36 6 36 35 5 37 7 40 6 36 33 42 34 39 7 37 7 37 40 32 33 8 43 5 38 38 40 35 35 36 5 3833 6 Blotch 7 8 ••••• 8 • 7 7 7 •• • 8 38 6 8 8 • •• • • 7 7 7 7 •• 8 8 •• 8 8 8 8 7 • 0 7 87 8 7 • 0 •• 7 7 7 R ocular L ocular •• • ••• «•• 12 • 13 12 8 8 12 13 12 11 11 8 8 40 • •• 0 0 •• •• 12 11 13 12 12 12 11 12 6 7 11 11 R i-labial L i-labial •• 0 12 12 12 8 12 12 • 12 12 11 12 12 8 8 11 13 12 8 8 39 11 • 12 12 11 •• •••• 12 11 12 12 8 8 10 10 11 11 •••• ••••• 12 12 • 11 11 12 11 11 12 13 12 11 11 12 8 8 36 11 11 11 12 11 12 12 12 11 11 11 12 13 11 ••• •••••• ••• 0 •••••• • 32 12 0 29 29 • 24 12 28 29 27 23 25 11 11 12 12 29 11 11 11 11 24 29 24 27 24 28 22 12 30 28 23 11 12 12 12 8 30 C-048 C-051 C-052 25 C-050 C-045 22 12 11 C-046 21 11 11 12 C-043 C-021 C-020 B-819 C-016 25 C-018 B-761B-762B-774 28 23 11 11 11 11 11 12 11 8 8 36 B-547 B-5S9 B-702 C-015 B-415 B-300 B-266 A-3212 A-3211 A-3210 A-3205 A-3203 A-3204 A-3197 A-3202 A-3195 A-3196 28 Number Caudal R s-labial L s-labial A-3192 A-3187 A-3194 A-3184
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. • • • 375 342 390 348 474 384 399 435 371 418 347 534 406 376 340 406 • 35 42 32 34 394 34 45 420 34 41 362 27 329 39 41 34 387 38 41 41 364 TL Total 1. ••• ••• •• • •• 333 307 360 365 375 358 359 32 391 321 385 33302 418 401 317 27 344 308 360 33 393 388 45 433 335 353 323 SVL • • • • 8 6 • • 31528 343 7 6 • • 6 • • 351 33 8 8 • • 8 6 • • • • 36035 395 6 • • 7 5 6 • • • • 6 • • 88 • • 398 50 448 5 • • 7 7 8 rina Tail Head 1. Head w. • 39 9 34 42 42 42 44 38 40 8 308 40 32 39 5 • • 40 8 • • 36 32 7 370 48 37 37 41 7 477 57 4340 6 • • 38 7 302 40 • • • • • • • • • • 1 • • • 7 39 7 8 8 38 7 8 7 7 8 36 6 • • 37531 • 8 35 6 • • 330 • 9 37 7 8 38 5 • • 37531 L L ocular Blotch •• • 8 8 8 7 7 8 8 4510 41856 8 8 77 7 7 42 8 8 8 7 7 7 7 8 R ocular 12 12 8 11 13 •• 12 8 1213 8 12 8 11 11 8 8 36 11 1212 8 8 12 8 8 12 8 11 11 8 8 36 8 • • 12 8 8 L i-labial ••••• • ••• 12 11 11 12 12 • 13 11 11 12 12 12 11 11 8 8 43 11 12 12 13 8 8 11 •••• • ••• 12 12 12 11 12 11 12 1212 12 13 12 1212 12 12 12 12 12 12 11 11 12 12 12 8 12 • •• • 12 12 12 11 11 12 ••• 12 11 11 11 8 8 11 11 11 11 12 12 12 12 8 8 41 12 12 11 11 11 11 R s-labial L s-labial R i-labial •• •• • 3025 11 22 11 10 •••••• 25 30 21 29 24 27 21 22 11 12 23 11 22 28 11 11 11 28 11 12 22 25 11 12 12 C audal C-158 C-176C -177 30 C-162 C-151 30 11 11 C-148 C-157 C-141 C-142 C-125 C-128 C-129 C-123 C-126 C-121 28 11 C-122 24 11 11 C-108 C-120 25 C-105 23 C-101C-104 21 C-102 C-099 C-lOO C-093 28 12 C-092 28 11 11 C-087 C-086 C-091 30 13 12 C-082C-083C-084 C-085 23 28 28 13 11 11 12 12 12 N um ber C-058 30 12 C-057C-072 29
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 132 • 356 328 382 202 214 221 430 294 227 318 300 232 435 352 325 372 •• • •• 39 368 19 184 36 46 25 295 32 25 32 318 26 27 37 37 41 45 435 TL Total 1. • • 165 292 349 33 201 20 342 42262 384 284 34 202 274 385 43 428 205 363 33 396 315 400 35 331 288 320 30 350 335 30 365 380 45 425 390 • • 286 9 186 16 • • • • 12 308 25 333 11 11 31714 39 329 11 11 350 30 380 11 11 11 370 40 270 410 • • • • • • • • • • • • • • 19 • • 19 • • • • • • • • 1918 10 384 • • • • 20 20 8 20 7 6 8 5 7 5 14 9 196 18 •• 8 8 9 9 7 8 • • • • 6 7 7 • 8 • • • 7 9 9 6 7 9 ring Tail Head I. Head w. SVL • • • • • • • • 3638 43 5 41 7 40 35 6 44 39 34 7 34 37 35 39 42 9 39 34 34 39 7 37 37 41 41 7 37 39 Blotch 6 78 39 38 6 14 7 • • 8 8 36 7 34 8 35 8 42 8 •• 7 8 8 8 8 8 L L ocular •• •• 7 7 7 • 8 ••• 8 7 7 8 8 •• 8 8 •• 8 8 8 8 ••• 8 ••• • •• • 13 •• 1313 8 8 ••• 11 8 12 11 13 8 • 12 •••• 11 13 8 13 12 12 13 8 8 12 12 7 12 12 11 8 8 11 13 8 8 11 7 • 13 • 13 • 12 12 10 11 10 11 11 • 12 12 13 13 12 11 12 11 12 13 8 11 13 R i-labial L i-labial R ocular • • 12 11 • 11 13 •• 12 11 11 10 13 11 12 11 11 11 ••• • ••• 12 12 •••• 12 12 12 11 12 13 12 • •• • 11 11 12 12 •• 12 12 11 12 12 13 11 12 12 12 12 12 11 12 12 8 8 • • • • • • 23 • 27 11 11 11 11 24 29 28 23 28 29 23 11 11 11 26 13 28 29 12 SM SM 702 SM 716 28 26 SM SM 695 26 SM SM 687SM 690 22 28 11 11 11 SM 679 SM 681 22 11 11 13 SM 678 24 12 SM SM 653 SM 675SM 676 28 23 11 10 11 11 C-367 C-360 C-352 C-363 C-345 25 11 C-343C-344 28 27 C-342 C-339 C-338 C-337 C-304 C-294 C-230 C-297 C-275C-293 29 23 11 12 C-220 21 C-221 C-233 C-216 25 12 12 C-207 Number Caudal R s-labial L s-labial C-209 C-184 C-189 27
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 133 303 325 300 386 318 343 253 507 484 460 390 459 469 356 424 276 27 354 32 302 41 430 54 410 50 355 35 382 42 450 57 331 41 372 410 49 415 54 SVL TL Total 1. • 12 296 29 11 259 41 11 288 30 11 230 23 12 14 17 15 17 13 320 36 •• •• • 17 18 20 20 13 345 38 383 21 24 14 22 21 Head 1. H ead w. 6 7 6 17 5 7 4 21 14 9 10 16 10 26 11 28 rinfi Tail 34 39 42 9 34 7 36 38 9 38 8 35 41 • 8 38 6 20 12 8 33 • 7 34 77 36 7 • 8 8 7 7 • 8 8 8 8 7 7 34 7 • ••• 12 12 12 12 11 11 8 8 33 6 10 12 L L i-labial R ocular L ocular Blotch • • 13 13 11 11 12 11 8 8 11 11 8 11 12 8 8 40 11 • 13 12 12 12 12 12 8 8 388 12 10 12 12 11 11 11 8 12 12 • 11 12 12 11 12 11 U 11 13 10 11 11 11 R s-labial L s-labial R i-labial 16 11 11 12 12 8 25 22 12 33 30 27 25 UCM-57337 UCM-56464 UCM-56463 UCM-56216 25 UCM-52027 UCM-52174 28 12 UCM-19755 UCM-25642 29 UCM-42250UCM-42373UCM-52026 28 30 30 11 12 12 12 12 12 12 SM SM 791UCM-19754 25 27 UCM-19973 UCM-25625 24 11 11 SM SM 793 23 SM SM 784 Number Caudal
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 134 R53WT13SSEC6SE R52WT14SSEC7NW R52WT14SSEC7SW R54WT11SSEC5SW R52WT13SSEC9SW R54WT14SSEC4SE R52WT14SSEC8SW R52WT14SSEC7SW R52WT14SSEC8SW R54WT14SSEC4SW R52WT14SSEC19NW R54WT17SSEC17SW R52WT14SSEC19NW R52WT14SSEC19NW R60WT16SSEC4NW R52WT14SSEC19NW R52WT14SSEC19NW R60WT18SSEC36SE R52WT14SSEC19NW R52WT14SSEC19NW R54WT18SSEC18SE R54WT15SSEC14SE R52WT13SSEC19SW R47WT18SSEC25SW 11 R52WT13SSEC31NW R52WT13SSEC31NW 1 1 R52WT14SSEC19NW 3 3 2 1 2 R52WT14SSEC19NW 2 2 22 R55WT14SSEC2SW 2 arrangement 5 5 •• 15 12 15 3 15 1 R52WT14SSEC7SW 20 3 10 1 10 3 R54WT17SSEC31SE 10 1 10 3 %belly Belly color Location 1 20 1 20 1 R52WT14SSEC19NW 1 3o 10 1 3 2 15 1 20 3 R52WT14SSEC8SW 1 20 1 R52WT14SSEC7SW 1 10 1 10 1 1 10 1 R55WT14SSEC3SW 1 10 1 1 15 1 2 2 Belly 1 1 20 1 1 1 2 10 2 1 2 10 1 1 1 20 3 R53WT14SSEC24NE 11 1 35 1 1 3 I 15 1 1 30 3 1 1 10 3 1 I 20 3 1 1 1 1 1 1 20 3 1 2 1 1 3 1 1 2 3 1 1 1 1 1 1 4 1 1 1 4 1 1 3 1 1 3 1 1 25 5 1 1 1 1 1 2 2 2 4 2 0 0 3 0 0 0 2 0 20 3 2 1 0 0 0 1 1 1 1 15 3 1 1 1 2 0 1 1 0 3 2 1 0 0 1 1 1 10 0 1 1 0 0 0 41 31 1 1 31 0 1 41 31 31 B 31 11 31 5C 31 0 4C 61 4C 1 31 21 21 seg. color color colored MISSINGMISSING 0 1 MISSING • 0.092 31 0 0.127 0.117 4C 0.127 0.134 0.105 0.093 0.144 41 0.09 0.099 0.127 0.124 0.085 4C 0.089 0.114 0.127 0.123 5C 0.102 6C 1 0.108 3C 2 1 1 0.095 0.093 11 0.127 0.114 TL/SVL Rattle Lyre Ground Blotch color • • • • 31 51 0.118 61 1 • • • • 30 ••• • • 32 0.082 41 • 5 • 38 35 0.103 51 20 0.096 4C 33 27 42 0.093 4C 31 34 0.094 41 Wt. A-1302 A-1300 A-1301 38 A-1299 A-1294 A-1295 A-1282 30 0.086 A-1273 A-1276 35 A-1287 A-1270 A-1271 A-1272 A-1262A-1263 42 0.149 A-1261 A-1260 A-1259 A-1257 54 0.124 A-1258 62 A-1256 38 A-1253 A-1255 A-1193 116 0.114 A-1190 A-1243 A-1254 35 0.091 A-0958 A-1035 A-1072 N um ber A-0493 A-0625 A-0959 A-0345 A-0019 A-0404
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 135 Location R52WT20SSEC9SE R56WT14SSEC6SE R54WT13SSEC2SE R58WT17SSEC2SW R54WT13SSEC1SE R53WT13SSEC6SW R54WT14SSEC32NW R52WT14SSEC18SW R52WT14SSEC18SW R52WT14SSEC18NW R52WT14SSEC18SW R52WT14SSEC19NW R52WT14SSEC19NW R52WT13SSEC31NW R52WT14SSEC18NW R54WT12SSEC17SW R52WT14SSEC18NW R52WT14SSEC19SW R52WT13SSEC30SW R52WT14SSEC18SW R52WT14SSEC19,308631 R52WT14SSEC19,308631 R52WT14SSEC19,308631 R52WT14SSEC19,308631 • • 2 R58WT17SSEC2SW 22 R52WT13SSEC30SW R55WT14SSEC12NE 3 R52WT14SSEC7NW 2 1 R52WT14SSEC18SW 2 R52WT14SSEC31SW 3 2 Belly color arrangement •• •• 5 3 7 15 3 15 1 10 3 R52WT14SSEC19.30&31 15 25 3 20 1 25 1 R52WT14SSEC19,308631 20 12 2 R52WT13SSEC30SW 20 3 15 20 1 10 15 20 20 1 20 3 % belly colored 1 1 1 • I 4 15 1 4 1 20 1 R52WT14SSEC18NW 2 1 30 3 2 1 2 1 20 1 1 7 3 R53WT13SSEC6SW 2 30 1 2 15 2 color 1 1 30 1 1 3 1 3 1 15 1SSEC19,30&31 R52WT14 2 1 1 1 1 1 1 1 15 1 1 1 30 2 1 2 Blotch color Belly ••••1 1 1 ••• •••• •• 2 2 2 4 I 1 1 15 2 1 2 1 1 2 10 3 1 1 1 1 4 3 4 2 2 1 4 2 color 1 2 0 0 0 0 2 2 0 0 0 0 0 2 Lyre G round 11 1 3 1 21 0 2 1 31 0 31 0 1 1 1 41 21 21 B 0 1 41 2121 0 6 B B 0 1 1 2 51 1 31 0 31 2 3 21 0 1 1 21 31 1 1 1 2 4C 1 4C 5C see. MISSING 0 MISSING 1 1 1 0.13 0.123 0.1310.076 11 1 0.126 0.083 0.09 0.121 0.122 0.081 0.124 0.116 0.113 0.142 0.105 2C 1 1 I 0.126 31 1 0.084 0.097 0.094 0.134 0.123 3 0,115 0.122 51 2 0.091 0.114 TL/SVL Rattle • • • • • • • • • • • 55 • 5 0.11 30 28 0.094 21 29 73 0.11 32 47 16 0.112 23 0.084 4C 1 6 34 44 27 39 0.09728 41 44 26 0.091 5C 1 Wt. A-1357 A-1354 A-1356 A-1352 A-1355 A-1350A-1351 23 0.095 A-1353 A-1348 A-1349 A-1347 A-1345 A-1346 A-1341 40 0.121 A-1343 A-1344 A-1323 A-1336 A-1330 A-1342 A-1328 A-1315 A-1316 6 A-1322 33 A-1313 A-1309 A-1311 38 0.096 5C A-1314 25 0.116 4C 0 1 1 A-1312 A-1307 30 A-1308 A-1306 A-1305 A-1310 N um ber A-1303 A-1304
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 136 Location R54WT20SSEC6SE R52WT14SSEC6SW R52WT14SSEC6SW R54WT21SSEC6NW R54WT18SSEC30NE R56WT15SSEC30NW R54WT20SSEC19SW R52WT14SSEC18SW R52WT14SSEC18SW R56WT15SSEC26SW R54WT14SSEC20NW R54WT15SSEC14SW R52WT14SSEC19.30&31 R52WT14SSEC19.30&31 R52WT14SSEC19.30&31 R52WT14SSEC19.30&31 R52WT14SSEC19.30&31 R52WT14SSEC19.30&31 R52WT14SSEC19.30&31 R52WT14SSEC19.30&31 R52WT14SSEC19,30&31 R52WT14SSEC19.30&31 R52WT14SSEC19,30&31 R52WT14SSEC19.30&31 R52WT14SSEC19.30&31 3 R54WT19SSEC5NW 1 • 1 3 R54WT17SSEC31SE 2 • 2 2 1 1 3 2 R52WT14SSEC19.30&31 2 2 2 3 2 2 Belly color arrangement 15 3 10 15 2 15 1 R52WT14SSEC18SW 1515 3 25 3 R54WT17SSEC19NE 25 20 15 1 40 10 3 R52WT14SSEC19.30&31 15 15 40 35 45 % belly colored 1 1 5 ••• • 1 10 •• 1 1 30 3 1 5 2 ••• • 3 15 4 4 4 20 2 R52WT14SSEC31SW 1 10 1 35 1 R52WT14SSEC19,30&31 1 20 3 1 20 1 R52WT14SSEC19,30&31 4 1 2 52 0 0 R52WT14SSEC19,30&31 2 2 Belly color 1 4 4 2 I 15 2 4 • • • 4 2 3 1 2 1 25 1 3 1 2 3 3 Blotch color 1 1 •• 3 • • 1 • 2 2 2 2 1 1 1 1 1 2 2 4 color G round • ••• •• • 0 1 1 ••••• 0 1 1 • 0 0 5 3 00 1 1 3 0 1 5 0 1 0 1 3 1 1 20 3 R52WT14SSEC19.30&31 1 2 0 6 3 1 0 2 0 0 6 0 1 1 1 0 5 1 0 Lyre 41 21 21 3C 0 6 1C 0 21 5C 11 0 1 31 0 6 1 4C 3C 0 3C 0 I I 1 40 MISS 0 see. R attle MISSING • • • • 0.12 0.113 11 0 0.096 0.123 0.104 3C 0.122 0.125 5C 0.084 21 0.119 41 0.107 0,135 0.091 0.097 0.091 5C 0.086 11 2 0.113 21 0.086 0.137 41 0.109 •• • • • • • • • • • • •• • • 44 29 0.124 28 28 0.083 21 29 0.126 40 4240 0.093 3C 66 0.133 51 36 36 31 43 0,086 11 0 24 23 A-2878 A-2833 A-2717A-2835 19 0.084 11 0 1 A-2726 A-2682 A-2510 A-2512 A-2467 A-1539 A-2328 A-1533 A-2301 A-1534 7 0.127 A-1387 A-1496 A-1380 A-1386 A-1379 A-1378 A-1373 A-1372 A-1369 A-1370A-1371 33 A-1367 A-1368 46 0.128 31 A-1366 37 0.085 4C Number Wt. TL/SVL A-1364 A-1365 A-1363 A-1359 A-1361 A-1362 26 0.118 MISSING A-1358 54 A-1360
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Location R56WT16SSEC4SE R53WT13SSEC1SE R52WT14SSEC6SW R53WT14SSEC2SW R53WT13SSEC4SW R53WT13SSEC6SW R54WT18SSEC19SE R53WT14SSEC5SW R53WT14SSEC5SW R55WT21SSEC3NW R55WT21SSEC3NW R52WT14SSEC30NW R52WT14SSEC7SW R52WT14SSEC18SW R52WT13SSEC31NW R52WT14SSEC18SW R52WT13SSEC19NW R52WT14SSEC6SW R52WT14SSEC19NW R56WT15SSEC26SW R52WT14SSEC18SW R54WT17SSEC31SE R54WT16SSEC32SW R54WT19SSEC32SW R54WT13SSEC32SW R54WT11SSEC29SW R54WT18SSEC29NW • 2 o 2 2 2 R52WT14SSEC7SW 2 R52WT14SSEC19SW 2 R53WT14SSEC2SW 2 R52WT14SSEC7NW 2 2 2 R54WT14SSEC4SE • 2 • 3 R56WT15SSEC8SW 2 2 R49WT14SSEC16NW Belly color arranRement • 30 10 15 15 30 25 1 15 20 15 2 20 2 R54WT18SSEC32NW 20 2 R55WT21SSEC2NW 30 35 3 20 3 % belly colored 1 11 20 1 25 10 3 1 20 1 25 1 10 •• 1 25 1••• 10 2 ••• I 1 20 2 4 4 1 15 1 3 15 I 1 40 1 2 •• 4 4 2 ••• • • 1 50 3 4 1 40 2 3 20 2 4 4 4 Belly color 1 1 • 1 1 • 1 2 1 15 2 3 3 1 • o • 4 3 2 3 3 4 3 3 Blotch color 1 1 3 1 1 1 1 1 3 2 1 1 4 1 4 1 2 4 2 •• 6 1 5 5 6 2 5 3 color G round •• • •••• • 0 1 0 • • • • • 0 0 1 1 0 1 • • 0 ••• 0 1 0 5 Lyre B 0 1 B 0 B 0 11 0 1 21 41 61 41 31 4C 4C 41 31 4C 6C seR. R attle ••• ••• 0.09 0.103 B 0 1 0.091 0.124 0.128 B 0 1 1 0.129 0.131 31 0.093 6C 0.148 0.114 31 0.086 0.129 0.115 0.114 0.123 0.127 41 0.086 0.137 0.122 0.128 0.135 31 0 8 0.119 B 0 1 •• 7 • 9 0.117 • • • • • • • • • ••• •••• •• • 60 60 40 67 40 0.128 MISS 73 0.131 46 60 Wt. TL/SVL A-3184 A-3182 6 A-3173A-3183 8 8 A-3181 A-3172 A-3170 30 A-3171 29 0.139 A-3155 A-3159 A-3149 A-3139 46 0.093 6C 0 1 A-3150 A-3138 A-3142 A-3140 A-3097 A-3122 16 0.118 A-3096 A-3095 35 0.136 4C A-3094 A-3090 A-3093 31 A-3028A-3033 30 0.13 4C A-3046 A-2991 A-3031 A-3001 A-2988 A-2969 N um ber A-2944 A-2955 A-2956 A-2968 A-2948
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 138 N/A N/A Location R52WT14SSEC3SE R54WT19SSEC7SE R46WT19SSEC2NW R54WT20SSEC6SW R54WT13SSEC31NE R56WT16SSEC5SW R55WT21SSEC2NW R46WT27SSEC31SE R52WT14SSEC19SW R52WT14SSEC18SW R52WT14SSEC19SW R52WT14SSEC19NW R52WT14SSEC18SW R52WT14SSEC19NW R52WT14SSEC19NW R53WT14SSEC12SE R52WT14SSEC30NW R53WT14SSEC24NE R56WT13SSEC17SW R52WT14SSEC18SW R52WT14SSEC19SW R52WT14SSEC19SW R52WT14SSEC18NW R52WT14SSEC31SW 1 R52WT14SSEC19NW 1 3 • • 2 2 R52WT14SSEC30NW 2 3 R52WT14SSEC30NW • • • 2 R52WT14SSEC30NW 2 3 R56WT19SSEC28NW 2 3 R54WT14SSEC31SE 2 Belly color arrangement 5 2 R49WT26SSEC23NW 15 10 20 25 40 25 20 2 15 25 40 1 20 2 20 2 % belly colored 1 30 1 20 2 R52WT14SSEC30NW 3 4 4 3 25 2 R52WT14SSEC18SW •• 2 2 1 20 2 2 •• 1 20 1 1 25 2 ••• 1 30 2 R52WT14SSEC30SW 2 color ••• 2 1 3 1 10 2 • 3 1 20 1 2 2 4 1 1 2 3 3 2 15 2 2 2 Blotch color Belly • 6 3 1 •••• 1 1 1 5 1 1 25 2 2 1 •• 2 1 3 1 15 1 •• •••••6 3 1 15 1 6 3 1 20 6 4 4 color G round • 0 6 1 2 3 0 1 1 • •••••• 0 1 2 0 0 1 1 0 • ••••• • 0 • •• 2 0 0 0 5 1 Lyre 41 31 51 1 5 3 3 31 0 2 3 1 31 B 0 1 B 0 1 1 1 15 2 B 0 5C 4C 0 1 1 21 2 6C 0 31 seg. R attle •• ••• • 0.1 0.133 0.099 0.127 0.123 0.091 4C 0.1250.128 4C 0 3 I 0.088 31 0.094 0.088 31 0 0.075 51 0.132 0.124 41 0.125 0.092 21 0.122 0.121 0.098 0.124 41 0.108 0.132 0.087 0.079 •• • • • • • • • • • • • 8 0.1 B 0 48 5 0,106 B 0 1 7 51 0.123 51 27 0.094 33 24 6 47 40 29 10 77 34 32 0.093 31 Wt. TL/SV L C-057 C-051C-052 28 38 C-050 20 C-021 C-048 C-043C-045C-046 29 23 0.093 C-016 C-018 C-020 B-819 B-762 B-761B-774 C-015 37 B-547 B-559 B-702 B-415 B-266 B-300 A-3212 A-3210 A-3205 A-3211 N um ber A-3197 A-3203 A-3204 A-3195A-3196 6 0.083 B 0 A-3202 38 A-3187 A-3192 A-3194
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 139 SE Location R56WT16SSEC3NW R48WT14SSEC20NE R48WT14SSEC29SE R46WT14SSEC21 R47WT14SSEC33NE R53WT14SSEC6SW R52WT14SSEC6SW R48WT13SSEC28NW R51WT14SSEC11NW R48WT13SSEC16SW R52WT14SSEC19NW R52WT14SSEC7NW R52WT14SSEC18NW R52WT14SSEC19NW R52WT14SSEC18SW R52WT14SSEC18NW R52WT14SSEC30NW R53WT20SSEC16NB R52WT14SSEC19NW R52WT14SSEC18SW R52WT14SSEC19NW R52WT14SSEC18NW R54WT14SSEC17NW R52WT14SSEC18SW R52WT14SSEC19NW R52WT14SSEC19SW R52WT14SSEC19SW R52WT14SSEC19NW 1 • 2 3 R48WT13SSEC28NW 2 1 2 2 2 2 2 2 2 2 2 Belly color arrangement • 15 • 10 2 25 20 3 10 2525 2 3 R52WT14SSEC30NW 30 20 1 % belly colored 1 30 111 15 25 2 1 20 3 R48WT13SSEC33SW 1 20 1 1 25 3 R52WT14SSEC18SW 11 15 20 1 4 4 2 1 15 1 1 11 30 10 1 1 35 3 1 2 2 10 1 20 1 R52WT14SSEC7NW 2 3 20 4 35 1 R52WT14SSEC2SW color •••• •••• 2 1 3 4 2 2 2 25 2 4 1 20 3 4 11 13 35 1 2 R52WT14SSEC7SW 2 1 15 2 R52WT14SSEC7SW 2 3 •• 3 3 3 2 3 1 15 Blotch color Belly 1 • • 1 1 1 1 3 1 1 1 2 2 2 1 1 1 2 2 6 • 1 5 2 2 1 35 2 2 3 2 color G round • • 1 0 1 0 1 3 2 0 0 1 0 0 3 0 0 1 2 1 20 1 0 • 00 1 5 1 1 • 0 0 3 0 0 6 3 0 1 1 0 0 1 I 0 Lyre 11 31 21 31 0 31 41 51 0 2 51 0 4 41 31 0 31 31 4C 4C 5C 0 seg. _ R attle 0.13 0.13 6C 0.126 4C 0.114 0.089 4C 0.134 0.093 51 0.089 0.094 41 0.128 4C 0 1 0.085 5C 0.119 0.124 41 0.126 0.126 0.083 4C 0.127 TL/SVL ••• •• •• • •••• ••• 47 0.115 51 • • 67 38 0.12 5C 2 24 30 29 42 34 0.097 27 0.085 4C 37 36 27 0.083 50 28 0.127 4528 0.116 0.092 MISS 0 30 0.096 103 C-176 C-184 C-151 30 C-158 C-162 C-177 C-142 C-157 C-148 26 0.094 C-129 C-128 C-141 C-125 C-126 C-122 C-123 C-120 C -121 29 C-105C-108 32 47 0.089 C-102 41 0.086 C-IOI C-104 17 0.089 C-099 C-lOO C-092 C-093 C-085 C-086 C-087 C-091 C-082 35 N um ber Wt. C-083 29 0.122 4C C-084 C-058 C-072
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 140 Location R54WT14SSEC3SE R54WT20SSEC6NE R54WT14SSEC5SW R54WT14SSEC1 SE R54WT14SSEC1 R53WT14SSEC2SE R55WT14SSEC7NW R52WT14SSEC5SE R54WT18SSEC31NE R54WT20SSEC7SW R54WT20SSEC6SW R53WT14SSEC26NE R53WT14SSEC24NE R54WT19SSEC8SW R55WT21SSEC1NW R54WT18SSCE20NW R54WT17SSEC29SW R54WT18SSEC29NW R54WT14SSEC17NW R52WT14SSEC24NE R53WT14SSEC18SW R54WT16SSEC17NW R54WT17SSEC29SW RS4WT14SSEC18SW R52WT14SSEC19SW R52WT14SSEC19SW R52WT14SSEC19NW R54WT20SSEC33NW • I 1 2 R54WT15SSEC7NW 3 3 R54WT14SSEC5SW 3 2 R54WT17SSEC29SW • 3 2 R54WT19SSEC8SW 2 Belly color arrangement • •• •• 5 3SE R52WT15SSEC1 •• •• 10 3 • 10 10 10 1 1510 1 R55WT14SSEC7NW 10 1 20 1 R58WT20SSEC27NW 15 2 35 3 20 25 20 3 30 20 2 35 2 % belly colored • 1 1 1 • • 1 2 5 3 2 25 3 • 1 4 1 4 4 10 3 1 4 25 2 • 1 • 4 35 2 R52WT15SSEC6NW 2 10 Belly color 1 1 1 1 4 3 3 •• 4 • 1 2 5 3 3 34 1 10 1 2 Blotch color 11 1 I •• 1 1 1 10 1 1 1 1 1 11 I 1 2 5 1 1 1 1 •• 6 1 3 2 •• • 2 2 2 1 2 3 6 3 2 2 65 3 2 15 6 3 color G round 1 1 • • 1 • • • • • • • 20 3 1 • 0 2 1 1 1 • • • 0 0 0 0 2 2 1 2 30 2 0 1 3 Lyre 1 3 3 4 2 4 4 21 0 61 4C ses. R attle ••••• • ••••••• • ••• 0.12 0.12 0.0810.113 3 0 0.1230.119 0 0 0.123 0.086 0.09 0.092 1 2 0.095 0 1 1 1 0.093 0.122 0.124 0.123 0.115 0.095 0.112 0.132 0.112 0.0910.087 41 0.117 3C 0.128 0.094 4C • • • • • • • • • ft • • • • • • •• • 8 0.1 B 0 • • • • • 15 25 28 0.086 43 0.108 3 0 47 35 0.124 4C 24 SM SM 716 SM 784 SM 695 SM 702 SM SM 687 SM SM 690 SM SM 679 SM 681 SM SM 676 SM 678 SM SM 675 C-363 C-367 SM 653 48 C-360 C-344 C-352 C-345 C-338 C-342 C-343 C-304 C-339 C-337 C-275 C-293C-297 32 C-294 23 C-207 C-209 C-220 C-221 C-230 C-233 Number Wt. TL/SVL C-216 30 C-189 53 0.118
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 141 Location R55WT21SSEC31 R56WT14SSEC5SE R54WT14SSEC7NE R48WT17SSEC4SE R55WT14SSEC1SW R55WT14SSEC1SW R55WT14SSEC1SW R57WT26SSEC3NW R54WT14SSEC5SW R54WT18SSEC8SW R58WT16SSEC21SE R54WT18SSEC10NE R55WT15SSEC14SW R61WT32SSEC19NW R55WT20SSEC35SW • 2 2 3 3 2 2 2 Belly color arrangement 15 1 10 10 1 10 20 1015 3 20 25 50 3 20 3 R55WT20SSEC35SW 35 45 50 2 % belly colored • • • 1 10 1 1 12 1 Belly color •••• •• •••• •• •• 2 2 Blotch color ••• • • •• • • • • •• • ••• •• ••• 4 3 color G round • 0 0 0 0 0 0 3 1 Lyre 3 0 2 seg. 0.1 0.09 21 0.110.12 0 0.158 0 0.136 1 0.127 0.124 0.099 • 0.098 0 3 • 0.098 • 0.104 • • 0.122 0 UCM-57337 UCM-56216 UCM-56464 UCM-56463 UCM-52174 UCM-52027 UCM-42373 UCM-52026 0.11 0 UCM-19755 UCM-25625 UCM-42250 • 0.126 0 UCM-25642 0.13 0 UCM-19754 UCM-19973 SM SM 791 SM 793 Number Wt. TL/SVL Rattle
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 142
Appendix B
Identifications and morphometric data of Sistrurus catenatus edwardsi (Arizona and New Mexico)
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 143 • 140 148 144 138 149 149 145 144 142 145 143 146 152 140 148 V entral 8 12 1112 11 143 111010 149 146 12 1012 146 11 1010 146 140 10 10 11 12 11 145 10 13 140 10 145 11 143 Mid tail • • 17 12 17 17 17 19 1719 9 14 145 143 19 19 17 18 1917 12 140 17 17 17 19 19 12 17 19 11 Specimens are from •••• 23 23 18 2323 19 23 23 23 23 19 23 2 3 24 25 22 23 23 23 23 23 18 23 Number dorsal scale rows • • • 23 23 23 23 25 23 22 23 16 23 25 19 12 142 23 23 23 18 23 25 23 23 23 23 23 from jaw anus 1 1 head length Midbody Ant Sistrurus catenatus edwardsi. 1732 1957 2105 2017 2032 1922 23 23 21002107 23 23 25 18 2130 22 2329 1940 2325 23 2130 1952 2015 25 2055 2010 2015 2022 2054 2000 22 Cochise Cochise Cochise Cochise Cochise Cochise Cochise Cochise Cochise Cochise Cochise Cochise 2000 22 Cochise Cochise Cochise Cochise 2033 25 Cochise Cochise 2155 23 Cochise C ounty T im e D ate 8 /9 /9 3 5 /1 8 /9 4 5 /3 1 /9 4 7/7/95 Cochise 5 /1 7 /9 4 6 /2 8 /9 4 7/15/93 Cochise 7/3/95 Cochise 9 /2 4 /9 3 8 /1 3 /9 3 4 /3 0 /9 4 8/26/95 Cochise 8/14/93 Cochise 1935 7 /3 1 /9 5 7 /2 8 /9 5 7 /2 7 /9 5 7 /2 2 /9 5 7/22/95 Cochise 2100 23 23 7 /2 1 /9 5 7/17/95 Cochise 2220 23 23 1 1 1 1 1 1 2 1 1 1 1 7 /2 2 /9 3 2 1 2 1 2 2 1 1 9/5/93 Cochise 2000 23 2 I 8 /1 2 /9 3 2 1 1 1 1 2 1 2 1 8/13/95 Cochise 2108 1 1 1 2 1 1 1 1 2 1 2 2 2 1 ASU-30160 ASU-30161 2 1 ASU-30158 ASU-30159 1 1 ASU-30154ASU-30156 1 ASU-30157 1 1 1 5/20/93 Cochise 2230 21 23 ASU-30151 ASU-30152 ASU-30153 ASU-30155 ASU-30149 ASU-30150 95-74 1 2 8/20/95 ASU-30148 95-77 95-41 2 1 95-6095-62 1 1 8/12/95 Cochise 2035 95-45 1 1 8/3/95 95-35 95-36 1 1 7/28/95 95-34 95-30 95-33 1 1 7/24/95 95-26 95-27 95-05 95-20 1 1 Number Sex Age 95-02 2 1 7/3/95 Cochise 95-03 Arizona and Mexico. New Table 14. Identifications and morphometric data of
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 144 143 152 147 146 143 143 146 145 151 143 143 150 148 144 146 153 143 137 143 145 146 140 146 138 150 V entral 11 11 144 10 11 13 1011 151 11 10 11 10 11 139 10 11 10 11 145 12 11 Mid tail • 17 17 18 19 19 17 19 18 11 19 19 19 19 20 11 18 18 11 17 23 20 12 23 18 11 142 21 23 20 23 23 18 11 142 21 23 19 11 21 23 18 12 24 21 23 21 17 23 23 18 23 18 11 142 22 18 11 23 18 11 Number dorsal scale rows 23 21 21 21 23 24 24 23 23 23 23 23 23 23 21 21 25 21 23 23 18 11 23 25 23 23 2123 23 23 18 10 147 23 25 23 18 11 144 25 23 18 11 23 24 from iaw anus 1 1 head length Midbody Ant 1950 23 23 18 11 145 2050 2014 Socorro Socorro ChavesSocorro Chaves 25 25 23 18 11 Socorro Chaves 23 Chaves Chaves Socorro 23 23 Valencia 23 Valencia Valencia Cochise 2200 Cochise Valencia Cochise 2250 Cochise 2145 23 23 Cochise 2200 Valencia Valencia Valencia Cochise Cochise 2030 Cochise 2020 Cochise Roosecelt Bernalillo 22 23 • • • • • • • • • • • • 7/1/89 Valencia 7 /1 /8 9 Valencia 21 21 7 /9 /9 4 5 /1 8 /6 6 4 /2 2 /6 0 8 /2 3 /7 5 10/24/91 Socorro 8 /2 3 /7 5 10/14/91 10/14/91 7 /3 0 /9 4 8 /1 3 /9 4 7 /3 0 /9 4 7 /1 6 /9 4 7 /1 8 /9 4 1 1 1 1 1 1 1 1 1 2 1 1 1 1 1 1 1 1 1 1 1 1 1 2 1 1 1 2 2 1 1 1 1 2 2 9/1/78 Valencia 1 1 1 2 1 1 1 1 1 1 1 1 1 1 1 1 2 2 5/30/64 Valencia 1 1 1 2 1 8/12/94 Cochise 2150 24 23 2 1 7 /1 1 /9 4 2 1 7 /2 3 /9 4 2 1 7 /1 0 /9 4 UNM-56032 UNM-55142 2 1 UNM-55162 1 1 UNM-55163 UNM-54904 1 1 10/4/92 Bernalillo UNM-53913 UNM-54112UNM-54414 1 1 UNM-52891 UNM-52893 UNM-52894 UNM-53027 1 1 UNM-51942UNM-52129 1 1 UNM-52737 UNM-34658 UNM-4752 UNM-51941 1 2 UNM-32381 UNM-32059 UNM-30928 2 1 UNM-25362UNM-30927 1 1 5/20/65 UNM-198U UNM-17805 ASU-30171 ASU-30169 ASU-30168 1 1 ASU-30170 ASU-30165 ASU-30167 Number Sex Age Date County Time ASU-30162 ASU-30163 ASU-30164 ASU-30166
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 145 146 148 151 149 V entral 11 10 10 156 11 Mid tail 19 18 19 11 21 12 143 23 19 23 23 25 Number dorsal scale rows 23 23 23 19 24 26 from jaw anus 1 1 head length Midbody Ant Lea Lea Chaves Chaves Chaves 23 23 • • • • • Date County Time 6/18/94 Chaves 25 1 1 1 1 1 1 2 1 2 1 S ex Age UNM-59511 UNM-59510 UNM-60589 N um ber UNM-56872 2 1 UNM-56580UNM-56660 1 1
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 146 0 325 392 390 339 402 383 430 396 426 395 382 450 417 406 343 408 370 391 357 339 393 351 329 465 Total 1. • 3536 405 38 43 50 402 49 41 40 385 41 42 38 430 33 41 53 23 285 3347 350 39 39 47 407 39 54 46 30 44 28 317 40 366 TL 289 351 381 385 465 341 352 331 51 382 362 392 397 406 43 449 369 37 370 369 317 309 34 352 360 347 289 411 7 5 312 27 6 359 6 89 345 6 8 355 7 6 6 7 6 348 34 7 8 7 7 299 8 326 6 Tail rine SVL 3835 6 370 34 37 37 7 38 8 352 34 7 34 37 7 36 37 38 39 37 34 34 35 10 38 35 8 38 6 33 8 318 39 34 36 41 7 307 0 0 • 8 8 ••• 8 8 7 8 8 36 6 32031 351 9 8 8 8 35 8 7 8 8 8 • 87 40 5 262 7 37 7 7 8 39 8 9 8 36 6 312 27 8 8 8 38 8 8 0 8 8 • 8 8 8 8 7 8 8 8 7 8 8 • 7 8 7 7 37 7 8 9 8 35 7 7 8 • • • 12 # 12 13 9 13 12 1212 8 12 12 12 13 11 12 12 12 11 8 11 12 L L i-labial R ocular ocular L Blotch 0 • 0 • • 1213 13 9 10 12 13 11 11 12 12 11 11 11 13 8 12 11 11 11 8 8 40 8 32842 13 12 8 11 12 12 12 • • • 13 13 13 11 11 12 11 12 12 12 8 12 11 12 12 13 8 8 11 12 12 12 11 8 8 38 • • •• • • 12 12 • 11 11 12 12 12 12 11 13 12 13 11 12 11 12 11 11 11 11 10 12 1212 12 12 12 12 12 12 12 11 11 12 11 12 12 •• 30 26 11 29 12 12 29 12 26 29 11 11 12 12 9 23 26 23 32 30 27 25 11 11 25 11 10 11 11 8 27 24 26 24 30 11 12 32 26 11 11 12 30 28 24 32 12 28 25 Caudal R s-labial L s-labial R i-labial ASU-30167 ASU-30166 ASU-30164 ASU-30165 ASU-30161 ASU-30162 ASU-30163 ASU-30160 ASU-30157 29 ASU-30158 ASU-30159 33 ASU-30156 ASU-30151 ASU-30152 ASU-30153 ASU-30154 ASU-30155 ASU-30149ASU-30150 34 ASU-30148 95-7495-77 24 95-45 95-62 95-3695-41 30 95-60 30 11 12 11 12 95-33 95-34 95-35 26 N um ber 95-27 95-30 23 11 11 11 95-03 95-26 95-20 95-02 95-05 28 11 11
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 147 460 333 413 445 362 340 344 304 467 448 316 433 235 383 205 223 394 330 382 366 404 215 391 38 49 27 42 33 5055 412 27 18 31 46 23 3231 382 349 45 31 360 48 376 53 429 375 396 370 50355 43 420 398 317 412 395271 53 328 40 368 357 32 389 187 285 279 32 311 387 322 36 358 197 18 338 45 212 23 200 347 47 289 41 329 343 327 39 SVL TL Total 1. 8 285 35 320 7 6 418 42 5 7 7 304 29 8 320 6 313 5 7 89 362 6 5 7 6 6 8 5 5 7 6 318 6 350 6 5 6 368 36 6 9 9 30 33 31 38 38 9 34 35 34 34 39 31 36 34 7 32 34 37 7 32 33 39 34 33 31 7 337 34 38 38 38 Blotch Tail rinc 7 36 7 40 8 35 7 7 36 8 8 36 7 7 7 8 8 8 8 30 8 8 78 34 8 7 8 8 8 8 •• 8 8 8 8 8 8 8 8 8 35 7 8 8 8 7 7 36 9 7 7 8 8 8 8 8 8 7 7 8 8 8 8 7 9 12 12 11 8 8 13 8 8 12 12 12 12 12 11 12 12 12 12 12 12 11 7 12 12 12 12 8 13 12 12 11 8 12 11 12 13 8 12 8 0 13 12 13 13 • 11 12 12 12 12 13 11 12 12 13 12 13 13 12 12 8 12 13 8 8 13 R i-labial L i-labial R ocular L ocular • 12 12 10 12 12 11 12 12 12 12 12 12 12 11 11 11 12 11 12 11 11 11 11 12 11 11 12 11 12 11 12 11 11 11 12 12 10 11 11 11 11 11 12 11 12 12 11 10 11 11 10 11 12 11 10 11 11 11 11 11 12 11 12 32 32 25 25 32 12 12 12 31 25 24 32 31 31 11 30 25 31 11 31 27 30 27 25 28 10 11 12 11 8 8 32 11 33 11 11 32 25 11 12 13 24 UNM-60589 26 UNM-59511 UNM-59510 UNM-56872 UNM-56660 UNM-56580 31 UNM-56032 UNM-55162 UNM-55163 UNM-54904 UNM-54112 32 UNM-55142 UNM-54414 UNM-53913 29 11 UNM-53027 UNM-52894 UNM-52129 UNM-52891 UNM-52893 UNM-52737 UNM-51941 UNM-51942 28 U N M -30928 UNM-32381 UNM-4752 30 11 UNM-34658 26 11 11 13 UNM-32059 UNM-30927 UNM-17805 UNM-25362 UNM-19811 Number Caudal R s-labial L s-labial ASU-30171 23 ASU-30169 ASU-30170 31 ASU-30168 33 12 12
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. OOCWUO- OU« • IOUUU« UIO>-W (OIO-C0W • • 5 15 15 5 10 10 5 30 5 20 10 10 5 10 10 15 10 15 20 25 11 5 15 11 10 2 1 20 4 i 20 1 15 1 20 1 15 2 2 1 2 10 4 4 1 1 25 • 2 3 4 3 2 2 3 1 10 2 2 3 1 1 3 3 42 4 2 23 2 1 15 10 1 4 4 3 1 20 3 1 4 4 2 2 2 111 1 4 2 1 I I 1 • 6 1 ••• 2 6 3 2 4 1 5 2 11 2 4 6 2 2 1 4 4 6 2 2 1 2 5 3 1 20 1 6 11 4 2 11 11 11 11 11 41 1 1 1 11 31 31 21 51 11 1 4C 61 4C 11 11 4C 5C 31 3C 1 3C 4C 3C 4C 4C 3C 4C 1 • • 45 40 5C 36.4 31.4 29.9 22.7 87.4 26.2 14.4 40.1 4C 27.2 26.8 17.4 37.7 38.3 23.4 28.2 0 • 0 0 0 0 37.6 0 69.2 0 39.9 41 0 58.5 2 0 25.3 4C 1 0 0 39 0 40.2 4C 0 0 0 23.90 33.2 0.095 0 0.117 0.120 0 0.123 0 35.6 3C 0.087 0.1080.097 0 0 34.1 0.106 0.154 0.116 0 0.142 0.091 0 29.2 0.097 0.134 0.106 0.1100.127 0 0.111 0.131 0.128 0 37.6 4C 6 0.087 0.133 0.100 0.097 0.131 • ASU-30167 0.125 2 22.5 ASU-30166 ASU-30165 ASU-30164 ASU-30163 ASU-30161 ASU-30162 ASU-30156 ASU-30160 ASU-30159 ASU-30154 0.115 0 ASU-30157ASU-30158 0.129 0 ASU-30155 ASU-30152 ASU-30153 ASU-30150 ASU-30151 ASU-30149 95-74 0.088 0 ASU-30148 0.098 0 36.2 95-60 95-62 0.106 0 40.8 41 95-41 0.104 95-77 0.100 0 95-35 95-45 95-3395-34 0.123 0 30.3 95-36 95-26 95-30 Number SVL/TL Lyre Wt. Rattle seg, Ground color Blotch color Belly color %belly colored Belly color arrangement 95-27 95-02 95-0395-05 0.123 0 33.1 95-20 0.143 0
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 149 1 3 1 3 3 • • 3 2 3 2 2 3 1 3 3 3 5 5 5 1 5 • •• 52 1 •••• 10 2 1515 2 10 1 15 10 15 35 3 20 2 1530 2 10 15 2 1 1 1 1 10 1 1 1 1 10 2 I 10 1 I 5 • 4 25 3 1 3 4 2 15 3 3 • 32 1 1 • 3 1 4 1 4 • •• 32 1 10 3 3 1 3 32 1 1 5 1 3 1 10 2 4 4 25 2 3 1 1 4 1 1 4 6 2 1 5 6 2 1 • • • • 3 ••• 6 2 2 1 5 3 4 2 6 Ground color Blotch color Belly color %belly colored Belly color arrangement 51 2 2 1 51 21 3141 1 4 1 51 6 3 81 11 21 6 51 6 21 41 21 1 4 61 6 31 6 11 1 51 41 4 11 6 31 4C 31 31 5C 3C 3 6C 6C BUT 2 BUT BUT 1 BUT MISS MISS Rattle seg. • • • • • • • 31.2 21 1 29.1 40.4 • • •• •• •••• •• •• •• •• •• •• •••• •• •••• • •• • •• • • •• •• •• •• ••• •• •• 0 2 0 043.6 11 1 4 4 20 Lyre Wt. 0.141 0.101 0.131 0.124 0.085 0.121 0.086 0.133 0.135 0.122 0.138 0.134 0.090 0.122 0.109 0.119 0.115 0.112 0.091 0.142 0.135 0.097 0.098 0.091 0.134 0.119 SVL/TL UNM-59511 0.123 UNM-56580 UNM-56872 0.095 UNM-60589 0.100 UNM-59510 UNM-55162 UNM-55163 UNM-56032 UNM-56660 UNM-54904 UNM-54112 UNM-54414 UNM-55142 UNM-53027 UNM-53913 UNM-52891 UNM-52893 UNM-52894 UNM-52737 UNM-51942 UNM-51941 0.108UNM-52129 UNM-32059 UNM-34658 0.096 UNM-19811 UNM-25362 UNM-32381 0.115 UNM-30927 UNM-4752 0.133 UNM-30928 N um ber UNM-17805 ASU-30170 ASU-30168 0.140 ASU-30171 ASU-30169 0.094
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 150
Appendix C
Identifications and morphometric data of Sistrurus catenatus tergeminus (Kansas)
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. • • 31 31 29 29 25 26 27 24 28 29 29 25 28 30 26 31 30 C audal • •• 145155 28 26 147 147 145 149 149 24 148 28 151 149 22 148 31 149 145 143 143 144 V entral Specimens are from • • 11 11 158 « 14 13 10 11 13 147 11 140 31 13 Mid tail • 19 10 19 12 149 19 • 19 1819 19 9 12 19 12 149 19 13 148 19 13 149 28 19 12 20 10 146 27 21 20 15 20 12 20 19 19 19 11 152 19 18 a n u s 25 25 25 20 25 2525 18 10 146 24 17 27 25 25 27 25 25 25 Midbody A nt Number dorsal scale rows • • 25 25 25 25 25 25 23 25 25 24 24 25 25 Sistrurus catenatus tergeminus. 25 25 2525 25 20 11 25 25 20 10 155 27 25 25 20 25 25 24 from iaw — Reno 25 25 Trego 25 25 Pratt 25 Kiowa Barton 25 25 20 11 148 Barton Barton 25 25 Barton Barton Harvey 25 Barton Barton Russell Stafford • Date County 1 head length 4 /5 /8 6 9 /2 /9 2 7 /5 /6 5 Rice 4 /1 9 /5 7 8/10/93 Hamilton 5/14/86 Barton 25 25 6 /1 7 /9 0 5/16/54 Barton 5 /1 6 /5 4 7/15/25 Stafford 25 25 18 11 152 24 5 /1 2 /7 3 5/31/69 Barber 7/29/96 Barton 10/29/78 Barber • 2 8/21/96 Barton 25 1 3 /2 9 /8 6 • 1 1 1 9 /5 /6 2 1 1 2 5/3/86 Barton 25 25 18 11 1 1 1 Age 1 2 8/21/96 Barton 25 1 2 8 /2 1 /9 6 1 2 8/21/96 Barton 1 1 2 • 1 2 4/15/90 Trego 1 1 5 /1 /9 2 Riley 2 2 1 2 5 /1 0 /8 6 1 1 4/25/86 Barton 25 25 • • 2 2 5/5/86 Barton 23 I 1 1 1 2 2 2 1 S ex N-6 N-4 N-5 N-3 1 2 8/21/96 N-2 1 2 8/21/96 N -l KU-50314 KU-204875 2 KU-221506 KU-220808 2 2 KU-220807 KU-204878 1 1 5/14/86 KU-206333 2 KU-204879 KU-216164 1 KU-216206 KU-204877 KU-204876 KU-204873 KU-204874 2 KU-191968 1 1 6/2/72 KU-189153 KU-189157 KU-191967 KU-189149 KU-179749 KU-1606KU-1705 2 KU-154054 KU-158010 N um ber CHEY. CHEY. BOT. 1 1 Kansas. Table 15. Identifications and morphometric data of
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Number dorsal scale rows Number Sex Age Date County 1 head length Midbody Ant Mid tail Ventral C audal fromjaw a n u s N-7 1 2 8/21/96 Barton 25 25 19 1 1 148 31 Jl • CJfl O' ' O 0 O' 00 01 00 • — m • m 'O 00 m cs c . . o 1 152 153 250 231 594 567 238 239 214 231 332 231 719 586 227 307 472 343 467 262 Total 1. •• 18 266 48 445 20 27 234 21 236 23 27 26 246 26 25 245 25 240 35 42 27 23 218 62 555 5850 21 563 78 21 26 250 30 48 561 57 512 TL • ••• 194 20 195 397 223 205 204 207 217211 21 20 238 231 216 220 532 62 218 215 297 493 248 535 51 505 210 641 206 513 224 232 417 455 • • • 5 220 7 9 8 7 7 7 • 6 7 7 7 7 314 29 7 7 8 7 9 414 58 10 • • 37 32 39 40 8 43 44 40 36 8 39 6 39 40 39 41 7 4238 9 6 525 32 33 46 8 38 37 37 39 34 39 9 37 45 • • • • 77 4 1 35 6 7 • 8 7 39 6 8 7 8 8 8 7 39 6 279 28 8 7 8 8 8 8 L ocularL Blotch Tail rinR SVL •• • 8 7 35 5 215 7 8 8 8 8 8 7 8 7 9 7 7 7 6 7 7 8 8 36 7 8 7 8 7 • • •• 12 12 13 13 12 11 13 12 12 13 13 13 8 8 12 13 11 12 7 7 13 8 8 •• • •••• ••• • 13 11 12 11 11 13 13 8 8 12 12 13 13 13 14 12 12 12 • • 12 12 12 12 1312 12 11 12 12 8 8 8 11 12 12 12 12 11 12 12 11 12 12 13 12 8 9 41 8 13 12 13 11 L s-labial R i-labial L i-labial R ocular •• •• •• • • •• 11 13 11 11 11 12 13 12 11 12 12 13 13 13 13 8 8 12 12 12 12 1011 11 11 10 12 10 13 12 12 12 11 13 12 12 12 13 13 R s-labial N-10 N-8 12 N-9 N-6 N-7 N-4 N-2 N-3 11 N-5 11 12 N-l KU-204875 KU-220808 KU-221506 KU-50314 KU-216164KU-216206 11 11 12 11 13 12 KU-220807 KU-206333 KU-204878KU-204879 12 KU-204877 KU-204876 KU-191967 KU-204873KU-204874 12 KU-189153 KU-189157 KU-191968 KU-1705KU-179749 11 11 13 KU-189149 KU-158010KU-1606 11 12 12 13 13 8 KU-154054 Num ber CHEY. BOT. CHEY. Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 154 • 1 • • 1 1 1 • • 3 • 1 1 • • • • 3 2 2 • 3 3 2 • 3 2 3 3 3 Belly color arrangement • • • • 15 3535 3 50 15 40 4040 1 3 50 20 40 50 50 5050 1 70 50 40 •• 3 40 3 • 3 40 4 3 3 70 3 40 • •• 3 50 3 3 2 3 3 3 50 3 3 40 1 •• 5 3 1 • 52 3 ••• 4 6 2 • 4 • 6 3 4 3 6 3 6 6 4 3 40 4 5 B BB 5 2 3 3 40 45 BB 2 11 6 3 B B 6 B 11 31 B 5 3 51 31 4 31 3C 2C 2C 8 7.6 7.9 8.4 7.7 • 1 8.5 B 5 3 1 B 6 2 60 0 0 8.3 B 2 0 8.2 0 0 51 4 0 11 4 0 • 0 1 0 51 0 0 0 31 4 0 0 11 4 2 11 0 Lyre Wt. Rattle see. Ground color Blotch color Belly color %belly colored • • 0.130 0 0.097 0.106 0.121 0.114 0.121 0.1260.103 0 0 B 0.080 0 0.118 0 0.118 0 0.100 1 B 0.073 0.092 0.100 0,120 0 4C 0.102 0.116 0,094 0.1250.129 0 SVL/TL N-9 N-10 0.132 N-5 N-6 N-7N-8 0.095 0.098 0 0 6.8 B N-4 N-3 0.118 0 8.1 B N-2 KU-221506KU-50314 KU-204875 0.092 N-l 0.127 KU-220807 KU-220808 KU-216164 KU-216206 0.116 KU-204879KU-206333 0.117 KU-204878 KU-204877 KU-204876 KU-191967 KU-191968KU-204873 KU-204874 0.115 0 KU-179749 KU-189153 0.095 KU-1705 KU-189149 0.122 KU-189157 KU-1606 Num ber KU-154054 KIM58010 0.140 0 11 CHEY. BOT. CHEY. Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. VITA Justin Peter Hobert Master's Degree Candidate 1950 West County Road 16 Department of Biological Sciences Loveland, Colorado 80537 University of Northern Colorado Greeley, Colorado 80639 EDUCATION: YEAR DEGREE INSTITUTION AREA OF STUDY 1997 M.A. Biol. Sciences University of Northern Colorado Biology 1993 Bachelor of Arts Southern Illinois University Zoology 1988 High School Dipl. Thompson Valley High School CollegePrep EXPERIENCE: YEAR INSTITUTION POSITIONS 6/97- Colorado Natural Heritage Program Field Zoologist Colorado State University Fort Collins, Colorado 8/94-5/97 University of Northern Colorado Teaching assistant Greeley, Colorado Graduate assistant Field Biologist 8/91-5/93 Striegei Animal Hospital Surgical technician Carbondale, Illinois Animal caretaker 8/89-9/90 Institute for Behavioral Genetics Animal lab tech Boulder, Colorado Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.