Morphological variation in the Fringed myotis, Myotis thysanodes Miller (Vespertilionidae)
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Authors Wright, David Terry, 1937-
Publisher The University of Arizona.
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Link to Item http://hdl.handle.net/10150/318553 MORPHOLOGICAL VARIATION IN THE FRINGED MYOTIS,
MYOTIS THYSANODES MILLER, (VESPERTILIONIDAE)
by
David Terry Wright
A Thesis Submitted to the Faculty of the
DEPARTMENT OF ZOOLOGY
In Partial Fulfillment of the Requirements For the Degree of '
MASTER OF SCIENCE
In the Graduate College
THE.UNIVERSITY OF ARIZONA
1 9 6 6 STATEMENT BY AUTHOR
This thesis has been submitted in partial fulfillment of requirements for an advanced degree at The University of Arizona and is deposited in the University Library to be made available to borrowers under rules of the Library.
Brief quotations from this thesis are allowable without special permission, provided that accurate acknowledgment of source is made. Requests for permission for extended quotation from or reproduction of this manuscript in whole or in part may be granted by the head of the major department or the Dean of the Graduate College when in his judgment the proposed use of the material is in the interests of scholarship. In all other instances, however, permission must be obtained from the author.
SIGNED:
APPROVAL BY THESIS DIRECTOR
This thesis has been approved on the date shown below:
E. LENDELL COCKRUM Date Professor of Zoology ACKNOWLEDGEMENTS
For advice and assistance throughout this study., I wish to
thank my major professor. Dr* Eo Lendell Cockrum0 For assistance
in preparing the manuscript, I express my appreciation to Drs 0 Howard
Ko Gloyd and William Jo McCauleyQ For the loan of specimens or the opportunity to examine specimens, in their care, I. especially thank the
following: California Academy of Sciences, D 0 E 0 McClintock; Cleveland
Museum of Natural History, Po A& Gerstner; University of Kansas Museum of Natural History,. Ec Ho Hall and JQ K e Jones, Jf@ ; Los Angeles
County Museum, M 0 Gage; Michigan State University Museum, R 0 H 0
Baker; University of Michigan, Department of Zoology, Fo Ho Test; c Department of Biology, University of New Mexico, Jo So Findley and
Co Lo Jones; Department of Zoology, University of Utah, S* D 0 Durrant;
Department of Zoology, Washington State University, G„ E„ Hudson,
iii TABLE OF CONTENTS
Page
INTRODUCTION oeoeooeoocoooooooooooooo 1
MATERIAL AND METHODS © « © © • . © . • © © © © © © © © • . © 3
ECOLOGICAL DISTRIBUTION © © © © © © © © © © © © © © © © © © 4 Seasonal vain, at ions ©©©o©©©©©©©©©©©©©©© 4
GEOGRAPHIC VARIATION © © © © © © © © © © © © © © © © © © © © 10 Accounts of Subspecies © © © © © © © © © © © © © © © © © © 11 Myotis thysanodes thysanodes © © © © © © © © © © © © © © 11 Range © & ©-© © © © © © © © © © © © © © © ©© © © © © 12 Diagnosis ©©©©©©©©©©©©©©©©©©©©o© 12 Comp air is ons © © © © © © © © © © © © © © © © © © © © © 12 Remarks © © _ © © © © © © © © , © © © © © © © © © © © © © 12 Specimens examined ©©©©©©o©©©©©©©©©©© 13
Miyotis thysanodes arizonae © © © © © © © © © © © © © © © 13 Type oooooooooooooooeooooooooo 13 Range © © © © © © © © © © © © © © © © © © © © © © © © 13 Diagnosis ©©©©©©©©©©©©©©©©©©©©o© 14 Comparisons ©©©©©©©©©©o© ©©©©©©©©© 14 Remarks ©©©©©©©©©©©©©©©©©©©©©o© 14 Specimens-examined © © © © © © © © © © © © © © © © © © 15
My otis thysanodes mexicana ©©©©©©©©©©©©©©© 15
Type © o © © © o o © © © ©60 © © © © © © ©'© © © © © 15 Range ©o©©©©©©©©©©©©©©©©©©©©©© 15 Diagnosis ©©©©©©©o©©©©© ©©©©©©©©© 15 Comparisons © © © ©©©©©©©©©©o©©© ©o©© 16 Remarks © © © © © © © © © © © © © © © © © © © © © © © 16 Specimens examined © © ©©©©©©©©©©©©©©©© 16
Myotis thysanodes jewelensis » © © « © © © © © © © © © © 17
Typ Qooooo 0 0000 0 000000*0000000 17 Range © © © © © © © © © © © © © © © © © © © ® © © © © 17 Diagnosis © © © © © © © © © © © © © © © © © © © © © © 17 Comparis ons ©o©©©©©©©©©©©©©©©©©©© 17 Remarks ©©©©©©©© ©©o©©©©©©©©©©©© 18 Specimens examined © ©©©©©©© ©©©©©©©©©© 18
iv V
Page
Myotis thysanod.es washingtonensis „ o..o«o,*o. 18
Type o'© o © '. o • o o o o o o e o o o o o © , o o o o o o 18
Range ©ooooooooooooooooooooooo 18
DiagnOSIS oooeeeoooeoooooooooooo 18
COHip aH S ons ooooooe ooooooooooooo© 18 Remarks © © © ® © © © © © © © © © © © ©.© © © © © © © 19 Specimens esc amine d © © © © © © ©.© © © © © © © © © © 19
Myotis thysanodes minimus © © © © © © © © © © © © © © © 19
Typ e © o © © © o © © © © © © © © © © o-o o- o © © © © 19 Range © © © © © © © © © © © © © © © © © © © © © © © © 19
Diagnosis ©©©©©©©©©©©©©©©©©©©©©o 19 Comparisons © © © © © © © © © © © © © © © © © © © © © 20 Remarks © © © « © © © © © © © © © © © © © © © © © © © 20 Specimens examined ©.©©©© © © © © © © © © © © © © 20 ' ' ' ' . ' . ,^\ DISCUSSION © © © © © © © © © © © © © © © © © © © © © © © . © ■ (29-y
LITERATURE CITED © © © © © © © © © © © © © © ©,© © © © © © 30 LIST OF TABLES
Number Page
lo - Banding and subsequent in place recovery dates of individuals of Myotis thysanodes, 0 » 0 o » o « » » 8
2o Statistical data for measurements presented in
F i g s p 2 ^ 8 ^ 4 ^ and 5 <$ e e o o © © © © © © © © © © © © © 2 6
vi LIST OF FIGURES
Number Page
lo Distribution of the subspecies of Myotis thysanodeSo Subspecies are represented by the following
letters: A = M. t* thvsanodes; B - Mo ho arizonae;
C '= Mo to mexicana; D = M* t_o minimus; E - M 0 t 0
iewelensis; F = M. to washingtonensis.; G = Mo t* aztecuso O ’ Ss represent localities of specimens
examinedo © © © © © © © © © © © © © © © © © © © © © © © 21
2 0 Modified Dice-Leraas graphs of forearm lengths of six subspecies of Myotis thysanodes© Rectangles include the 95% confidence intervals© For explanation of letters 3 see Fig© 1 © © © © © © © © © © © © ©»© © © © 22
3© Modified Dice-Leraas graphs of metacarpal III lengths of six subspecies of Myotis thysanodes© Rectangles include the 95% confidence intervals© For explana tion of letters, see Fig© 1*© © © © © © © © © © © © © © 23
4© Modified Dice-Leraas graphs of tibia lengths of six subspecies of Myotis thysanodes© Rectangles in clude the 95% confidence intervals© For explanation of letters, see Fig© 1© © © © © © © © © © © © © © © © © 24
5© Modified Dice-Leraas graphs of lengths of maxillary toothrows, breadth across upper molars, and skull lengths in six subspecies of Myotis thysanodes © Rec tangles include the 95% confidence intervals© For explanation of letters, see Fig© 1© © © © © © © © © © © 25
vii ABSTRACT
Banding data indicate that in Myoti's thysanodes there is a
local separation of sexes during spring and summer3 and that this species is non-migratoryo This behavior results in a geographic isolation of populationSo An examination of 244 museum specimens taken from a large part of the range indicates that morphological variation occurs at a level sufficient to justify recognition of six
subspecieso These are M 0 to thysanodes^ arizonae, mexicana, jewelensis ^ washingtonensis ^ and minimuso The latter five are described here as new subspecieso
viii INTRODUCTION
The known range of the Fringed myotis, Myotis thysanodes
Miller.,' extends from, southern British Columbia, Canada, southward through most of the western,United States, and in the mountains of
Mexico to the state of Oaxacae Within this range, two subspecies are
currently recognized: Me t 0 aztecus and M. .jto thysanodes, Both were described by Miller and Allen (1928) <> M. jto aztecus is restricted to a small portion of this range, being known only from two localities in
Oaxaca (Hall and Kelson, 1959)» The huge extent of the geographic range of the nominant subspecies, M« to thysanodes, is surprising, especially in view of the fact that the several other species of
Myotis that occupy similar ranges (including Mo velifer, yumanensis, evotis, and californicus) are all separable into several geographic raceso
The primary aim of this study was to determine whether the apparent genetic homogeneity of the Fringed myotis implied by the cur rent taxonomic catagories is real or whether geographic variation does occur and simply has not been recognized and adequately described, A review of the literature revealed that not many specimens of the Fringed myotis have been taken. For example, when Miller and Allen (1928) pub lished their revision of the American bats of the genus Myotis, they had only 199 specimens of Myotis thysanodes available for study. In
)
i 2 contrast, they had 477 specimens of Mo velifer, 699 specimens of Mo yumanensis, and 576 specimens of M c californicuso
The present study involves an investigation of the morphological features of 244 specimens of the Fringed myotis, none of which had been examined by Miller and Allen (1928)» Further, the results of various banding studies involving bats of this species were also available; these have revealed several pertinent behavioral and ecological traits of the species that help to evaluate the morphological data obtained from the preserved specimens0 3
. MATERIALS AND METHODS
Museum study skins and skulls of 244 specimens of Myotis thysanodes thysanodes Miller and Allen were, examined0 Three body and thirteen skull measurements were takeno Body measurements included forearm length? tibia length, and length of the third metacarpalo
Skull measurements were greatest length, condylob as i1ar length, medial palatal length, length of maxillary toothrow, zygomatic breadth, mastoid breadth, cranial breadth, least interorbital constriction, greatest width across upper molars, greatest width across maxillary canines, length of mandible, length of mandibular toothrow, and depth of cranium0
Measurements taken by others were not used for statistical analysis0
All measurements were made with a dial caliper according to the methods described by Cockrum (1962) and are reported in millimeters»
Since sexual dimorphism at the 95 per cent level was not ob served in any of these measurements, both sexes were grouped in one sample for the purpose of this study* In some cases, small samples from nearby localities were grouped* 4
ECOLOGICAL DISTRIBUTION
That the habitat of Myotis thysanodes is the oak and pine forests of the Upper Sonoran and Transition Life Zones has been re ported many times (Swarth, 1929; Hooper9 1941; Ingles9 1948;
Hoffmeister, 1956; Findley and Jones9 19619 and many others)„ Data obtained through the bat banding program carried out by E„ L* Cockfum and others at The University of Arizona (personal communication with
Eo Lo Cpckrum) indicate behavioral patterns within the oak-pine habi tat that are important in a taxonomic evaluation of this speciese
Seasonal variations0 Data primarily from colonies,in Mohave
County9 Arizona, show that these bats separate into maternity colonies and male colonies during the spring and summer, although a few male individuals are usually present in the maternity colonies* Male colonies are found at higher elevations .than the female roosts and are more numerous but contain fewer individuals* Normally both males and females show a high preference for a specific cave as a summer roost, but males taken from maternity colonies show less preference for the cave from which they were taken than do individuals taken from all-male colonies* Both males and females also seem to prefer particular watering places* Banding data showing cave and watering preference are presented in Table 1* Hackberry Consolidated Mine represents a maternity colony, as shown by the high percentage of females to males and the presence of newborn young on 3 July I960*
Other maternity colonies not yet located are probably present in this vicinity as mist net records show high ratios of females to males A at watering sites at Democrat and Flag mines (Hualpai Mountains),
Stockton Hills mine (Cerbats Mountains), and in the Union Pass area
(Black Mountains)o The Madera Canyon colony represents a summer day roost for maleso
Banding records also demonstrate that there is some movement from one day roost to another in the summer months, but that this move ment is not over a great distance and is within the same general eco logical situation* Table .1 presents records of summer movements of individuals of this species*
Homing experiments, however, have shown that with this species there is a strong tendency to return to a particular roost, not only from one year to the next, as noted in Table 1, but also during the same summero For example, in Cochise County, Arizona, two females and one male were taken from Buckelew Cave, 5 miles north of Portal, and released on 3 September 1958 at the Southwestern Research Station, 2 miles west of Portal* They were recovered at Buckelew Cave the follow ing day* Also, a female from the Riggs Ranch, 12 miles southeast of
Dos Cabezas, was released at the Southwestern Research Station on 1
June 1958 and recovered at the Riggs Ranch on 6 September 1958, a dis tance of approximately 30 airline miles to the northwest, over the
Chiricahua Mountains * It seems likely therefore, that although more than one day roost in the same general vicinity can be, and are, utili sed by individuals when necessary, one particular day roost is preferred* 6
In late summer and early fall, dormant individuals of both sexes have been found in cool damp mine tunnels in Mohave County» These in
clude the following: One female was taken on 1 September 1961 in the
OK Mine, 68 miles north of Kingman in a desert area at 4000 feet ele- vation0 Air temperature in the tunnel was 16*7 degrees Centigrade0
On 17 September 1961, a single dormant male was taken in Sulphur tunnel
(air temperature 2l07 degrees Centigrade), 4 miles northwest of Oatman, and one male was taken in a wet tunnel 5 miles northwest of Oatman*
On 25 September 1961, three females were taken from the wet Jim Kane
Mine in the Cerbats Mountains northwest of Kingman*
Some active individuals have also been found in early fall in
Mohave County, but these have been in drier and warmer situations*
On 1 October 1961, a single male was taken in the mine tunnel on Lower
Burro Creek where Myotis velifer and Macrotus californicus are usually found* A single male was taken on 22 October 1960 in the attic of an abandoned house at Cave Springs, Bing Sandy River* Ten Plecotus townsendi and one Myotis californicus were also present* These two M* thysanodes were possibly young of the year or adults that had not yet accumulated enough body fat to undergo^hibernation, and were seeking a warmer environment in an attempt to prolong their feeding period*
Few Fringed myotis have been found in this general area during the winter* Two males were found on 21 January 1962 in Flag Mine, ele vation 7000 feet, in the Hualpai Mountains* Two females were found on
25 March 1961 in Hackberry Consolidated Mine* All of these animals 7 were torpid at the time of capture«, Thirty-six males and one female banded during the summer in the mine tunnel at Madera Canyon* Pima
County3. Arizona, were found torpid in that same tunnel during the winter
(see Table 1), 8
Table 10 Banding.and subsequent in place recovery dates for individuals of Myotis thysanodeso
Hackberry Consolidated Mine, Peacock Mountains, 28,o5 miles northeast Kingman, Mohave County, Arizona
Individuals Individuals Banded Recovered Male Female Date Male Female Date r-4 CM 32 00 3 July 1960 0 32 26 July 1960
0 172 14 August 1961
0 83 3 August 1963
26 154 26 July 1960 0 55 14 August 1961
0 344 3 August 1963
10 . 50 14 August 1961 0 17 3 August 1963
Stockton Hills Mine, Cerbats i Mountains 9 4000 feet, Mohave County, Arizona
4 12 6 July 1962 0 1 7 July 1962
0 1 1 July 1963
0 1 17 July 1963
9 21 8 July 1962 0 1 18 July 1962
1 0 1 July 1963
0 1 17 July 1963 9
Table 1 (Continued)
Mine tunnel, mouth of Madera Canyon, Pima County, Arizona
Individuals Individuals Banded Recovered Male Female Date______Male Female______Date 12 0 30 May 1959 8 0 3 August 1959
3 0 11 September 1959
5 0 11 October 1959
2 0 1 August 1961
2 0 10 August 1964
62 - 2 • 3 August 1959 11 0 1 September 1959
23 0 11 October 1959
8 0 26 October 1959
3 0 10 June 1960
1 0 6 June 1961
5 2 1 August 1961
3 0 16 August 1964
13 2 25 September 1960 0 4 1 August 1961
2 0 10 August 1964
0 1 4 October 1964
6 0 9 July 1963 3 0 10 August 1964
^Released at Kingman, Mohave County, Arizona, o 10 of which had also been recovered 26 July 1960. 3 5 of which had also been recovered 26 July 1960, and 5 of which had also been recovered 14 August 1961. 4 26 of which had"also been recovered 14 August 1961. 10
GEOGRAPHIC VARIATION
The distribution of Myotis thysanodes thysanodes Miller and
Allen is currently described as extending from Vernon, British Columbia,
Canada (Maklin,1938), through most of the astern United States, to
Michoacan, Mexico (Hall and Villa, 1949)„ Additional marginal records listed in Hall and Kelson (1959) are as follows:
Washington: Anatone (Jones and Webb, 1953), Blue Mountains
(Dalquest, 1938); South Dakota; Jewel Gave (Bole, 1935); New Mexico:
Espanola, Carlsbad (Vo Bailey, 1931); Texas: SE slope Mariscal Mountain
(Borell and Bryant, 1942); San Louis Potosi: Hda0 La Parada, Hda0
Capulin (Dalquest, 1953); Jalisco: Los Masos. La Laguna (Miller and
Allen, 1928); Sonora: near El Tigre (Burt, 1938); California: various localities along the Pacific coast; Oregon: Tillamook (Walker, 1942)0
Many of these authors have noted a wide degree of variation between samples of populations within the range of this subspecies, but have not compared material covering wide portions of the range0 The present study, involving an investigation of specimens from a large por tion of the range (Figure 1), indicates that- morphological features are not uniform, but rather there is considerable variation between even adjacent population samples0 This variation probably results from the behavioral patterns of these bats in that they occur in a limited eco logical range that is rarely continuous geographically0 Rather"it is a series of isolated ecological situations which are suitable for habita tion by the Fringed myotiso As a result of this separation, there is little gene flow between adjacent populations0 11
Patterns of morphological variation do occur3 and these dif
ferences are associated'with geographic areas0 . The magnitude of these
differences is such that they are best expressed as geographic races0
The following accounts define these groups in terms of morphology and
geography*
Accounts of Subspecies*
Abbreviations used to denote sources of specimens examined are
as follows: CAS, California Academy of Sciences; CMNH3 Cleveland
Museum of Natural History; KU9 University of Kansas Museum of Natural
History; LACM5 Los Angeles County Museum; MSU, Michigan State University;
UA? Department of Zoology, The University of Arizona; UM, University of
Michigan; UNM, Department of Biology, University of New Mexico; UU,
Department of Zoology, University of Utah; WSU, Department of Zoology,
Washington State University*
Figure 1 shows localities represented by these specimens*
Myotis thysanodes thysanodes Miller and Allen
Vespertilio subulatus H® Allen, Smithsonian Misc* Coll*, 165: 51, June
1864*
Vespertilio albescens evotis H* Allen, Bull* U* S *, Nat * Mus *, 43: 90, 14
March 1894*
Vespertilio albescens velifer H* Allen, Bull* U* S* Nat* Mus*, 43: 93,
14 March 1894*
Myotis thysanodes Miller, North Amer* Fauna, 13: 80, 16 October 1897,
type from Old Fort Tejon, Kern County, California*
Myotis thysanodes thysanodes Miller and Allen, Bull* U* S* Nat* Mus*,
144: 126, 18 April,. 1928.® 12
Range
Coastal mountain ranges of Oregon and California south to Kern
County, California, and then east to Mohave County, Arizona, including
Clark County, .Nevadao
Diagnosis
General appearance much as in M 0, evotis (Miller, 1897), but hairs
on dorsal surface of uropatagium in groups of 2 or 3 rather than soli
tary « Upper parts yellowish brown to darker olivaceous tones; under-
parts lighto Skull resembling that of M 0 evotis but larger, more robust,
broader; saggital crest well.developed when compared to M 0 evotis;
length of upper toothrow exceeded by greatest breadth across upper
second molars 0
Comparisons
For comparisons with Mo t.* mexicana, arizonae, and washingtoriensis,
see accounts of those subspecieso
Remarks
From observations made in this investigation, it is concluded
that specimens of M e tic thysanodes taken from near the type locality are
in an area of integradation with Mo .jto arizonae and that this area ex
tends through southern Nevada to include those specimens described by
Burt (1934) and by Deacon, ej: al (1964) and into Mohave County, Arizona*
Near topotypes from Kern County and specimens from Mohave County are
characterized by a high degree of variability in the shape, relative
position, and number of upper premolars 2 and 3 0 . The Mohave County specimens are more closely aligned with those from southern and northern 13
California than with those from populations to the east and therefore
are assigned to this race 0 There is a high degree of uniformity among specimens from northern California
Specimens examined
Total9 33, from the following localities: CALIFORNIA: , Trinity
County: 2 01 miles. ESE Wildwoodg I 9 CAS 6 Napa, County: Irwin Hall,
Pacific Union College3 1750 feet, 6, CASo San Mateo County: Barn
on Folger Estate, Bear Gulch Road 9 1 mile SSW Woodside 9.4 3 CAS 0
Monterey County: Carmel9 1-, CASo Fresno County: Mercy Mines 9 near
Mercy Hot Springs, 1, CASo Kern County: Carneros Rocks, 1500 feet, 14,
CASo ARIZONA: Mohave County: Twin Windmills, 4*5 miles SSE Kingman,
1, UA; 1 mile SW Union Pass, 1, UA; Flag Mine, Hualpai Mts0, 1, UA;
Stockton Hill Mine, N of Kingman, 1, UA; Tunnel, 26 miles NE Kingman on E slope of Peacock Mts0, 2, UA* . . .
Myo'tis thysanodes arizonae new subspecies
Z z m -
Adult female, skin and skull No 0 7320, The. University of
Arizona Department of Zoology; Heiser Springs, ca 0 5500 feet, Wupatki
Nato Monument, Coconino County, Arizona; 29 June 1960; collected by
Eo L 0 Cockrum, original number 2166*
Range
Northern and western Utah, northern Arizona east of Mohave
County and south to Mogollon Rim, northwestern New Mexico and south western ColoradOo 14
Diagnosis
Size large (see Table 2)* Color above darker than that of near
topotypes of Mo to thysanodes; parietals pronounced9 causing definite depression on superior surface of braincase when viewed from the side; saggital crest not well developed*
Comparisons ■ ?
Differs from Mo to thysanodes in the following features: color darker; size larger; rostrum broader and.proportionally shorter; zygo matic breadth proportionally narrower; from M* t* mexicana: color darker dorsally; external, and skull characters proportionally the same, but largero
Remarks '
The range of arizonae is here described to include specimens from northern Utah (Krutzsch 'and Vaughn, 1955) although these specimens were not available to me for examination* On a geographical basis, it seems to be more probable that bats from northern Utah would be more likely to exchange genes with those from within the subspecies arizonae than with those further north*
Specimens from Valencia County, New Mexico, are considered to be intergrades with M* t* mexicana and, for geographical reasons, are here assigned to arizonae*
Due to the apparent absence of intergrades with M* _t* mexicana in Arizona, it is suggested that the Mogollon Rim may act as an effective barrier against gene flow in this species* 15
Specimens examined
Total, 81j from the following localities: UTAH; Washington
County: Pine Valley, .36 miles N St. George, 6500 feet., 6 , UU;
Snow’s Canyon, NW of St. George/ 4, UU. ARIZONA; Coconino County; 5 miles W Flagstaff, 1, KU; Heiser Spring, Waputki Nat. Monument, 9, UA.
Navajo County; W side Holbrook, 3, UA. NEW MEXICO; Valencia County;
20 miles S Grants, 2, UNM; Spring, Niateo Canyon, Mt. Taylor Range, 1,
UNM; Mirabal Spring, Mt. Taylor, 1, UNM; La Mosca Tank, NE Grants, 1,
UNM; El Rito Tank, Mt. Taylor Range, 1, UNM; Bernalillo County; Isleta
Gave, 8 miles W of Isleta, 33, UNM; Escabosa, Mawzano Mts., 12, UNM.
Myotis thysanodes mexicana new subspecies
Type '
Adult female, skin and skull No. 11390, University of Arizona,
Department of Zoology; Pyatt Cave, W Boundary Ft. Huachuca Military
Reservation, Cochise County, Arizona; 5 June 1964; collected by J. L.
Osborne, original number 97.
Range.
Southeastern Arizona south of the Mogollon Rim, New Mexico south
from Bernalillo County, west Texas to Brewster County, and Mexico south
to Michoacan.
Diagnosis
Size large (see figures 2 and 3, table 2); color varying from ,
as light as specimens from near the type locality of M. t. thysanodes
to darker in the northern part of the range. 16
Comparisons
rCompared^to Me _t0 arizdnae, generally lighter in color; external
and skull characters proportionally the same except braincase slightly more inflated; size generally smaller®
Remarks
Few specimens from Mexico were available to me for study but
on the basis of Mexican material that was at hand,. I., feel it best to
include all of Mexico within the range of mexicana except that portion of southern Mexico described by Miller and Allen (1928) as inhabited by Mo to aztecuso A wide area of intergradation- with arizonae exists
in New Mexico 0 See remarks under M 0 t * arizonae*
Specimens examined
Total, 120, from the following localities: ARIZONA: Gila
County: Wilbanks Ranch, Sierra Ancha, 1, UA® Maricopa County: 20 miles SW Pumpkin Center, 1, UAo Madera Canyon (Santa Cruz and Pima
Counties) : 32 (26, UA, 6 , GAS)o Cochise County: Pyatt Cave, W Boundary
Ft 0 Huachuca Military Reservation, 4, UA; 12 miles S Dos Cabrzas, 5, UA; r
Blue Mt 0 Cave, 16 miles S San Simon, 2, UA; Barfoot Park, 8200 feet,
Chiracahua Mts,, 1, UA: South Fork of Cave Creek, Chiracahua Mtse, 3,
UA; Virtue Mine, 3/4 mile E of Portal, ca® 4800 feet, 1, UA; 1 mile
N Paradise, 1, UA; Reef Mine^ Huachuca Mts*, 2, KU® NEW MEXICO:
Catron County: Taylor Creek Range, 2 miles NE Wall Lake, Black Range,
12, UNMo Socorro County: Bear Trap Canyon, 19 miles W, 20 miles S,
Magdalena, San Mateo Mts®, 13, UNM® Lincoln County: 1 miles W
Arabela, 14, UNM® Otero County: Alamo Mt®, R13E, T26S, 9, UNM® 17
Hidalgo County; U-Bar Cave, Alamo Hueco Mts,, 4, UA; Inside House, OK
Bar, Double Adobe Canyon, 2, UNM; T29S, R19W, S32, 3, UNM; NW edge
Alamo Hueco Mts«, 1, HA. SONORA; 9 miles NE Imuris, 2, KU. . CHIHUAHHA;
25 miles NE Guadalupe yCalvo, Consolacion, 5100 feet, 1, LACM.
DURANGO; 4 miles SW La Pila, 3, MSU.
Myotis thysanodes jewelensis new subspecies
Type
Adult.male,, skin and damaged skull No. 106026, University of
Michigan, Museum of Zoology; Jewel Cave, Custer County, South Dakota;
10 August 1929; collected.by G., W. Phillips, original number 115.
Range
Known only, from two localities in southwestern South Dakota.
Diagnosis
Size medium, about that of M«. t. washingtonensis; about the same color dorsally as arizonae but darker ventrally; lighter in all re spects than'washingtonensis.
Comparisons.
Compared with M. t. arizonae, palate longer and narrower pos teriorly; braincase less sharply inclined anteriorly, no definite de pression of rostrum when viewed from, the side; braincase narrower, more gradually tapering anteriorly, when viewed from above; saggital crest less pronounced; compared with washingtonensis, skull longer, rostrum more robust; palate longer and.narrower; braincase narrower and tapering more gradually anteriorly when viewed from above. Remarks
Although this subspecies is known only from one locality in southwestern South Dakota, it: may be expected to occur westward into
Wyoming and perhaps be continuous with washingtonensis, provided it is able to cross the Rocky Mountains in Wyoming, Another possibility is an interrelationship with arizonae through southern Wyoming and northern Colorado, although this is the less likely situation since this race is morphologically more similar to washingtonensis.
Specimens examined
Total 3, from the following localities: SOUTH. DAKOTA; Custer
County; Jewel Cave, 2, (CMNH 1, DM 1); Custer State Park, 1, UM;.
Myotis thysanodes washingtonensis new subspecies
Type
Adult male, skin and skull No. 61-296, Washington State University
Residence Hall, WSU, Whitman County, Washington; 11 October 1961; collected by J. Wiggs and S. Nepell, original number not present on label.
Range
Southern British Columbia, Canada, south through the Blue
Mountains of eastern Washington to southwestern Idaho.
Diagnosis
Size medium; color dark, equaling that of M. t. mexicana.
Comparisons
When compared to jewelensis, palate broader and with shallower palatine fossa; maxillary toothrows less convergent anteriorally.
Compared to thysanodes, overall size smaller; palate relatively broader and shorter; braincase less abruptly elevated from rostral level;
saggital crest poorly developed.
Remarks
Mo to washingtonensis, although relatively close geographi
cally to Mo to thysanodes, is probably isolated from this race by the
central valley of Washington, Also3 lower elevations that exist in
southern Idaho and northern Utah isolate it from arizonae.
Since specimens from British Columbia were not available to
me this region is necessarily included in the range of this subspecies
on the basis of geography only, • ■
Specimens examined
Total, 3, from the following localities: WASHINGTON: . Whitman
County: Residence Hall WSU? 1, WSU, Columbia County: Tucannon Guard
Station, 1, WSU, IDAHO: Boise County; Karney Lake, 1,KU,
Mvotis thysanodes minimus new subspecies
: Type
Adult male, skin and skull No, 34863, University of Kansas,
Museum of Natural History; La Puerta Valley, San Diego County, California
collected by Phillip H, Krutzsch, original number 436,
Range ,
Known only from San Diego County, California,
Diagnosis
Size small; color light; tibia relatively longest of any sub
species of M, thysanodes, 20
Comparisons
Compared to mexicana^ skull size smaller but rostrum relatively
longer3 palate relatively broader and longer; tibia longerQ , Compared
to thysanodes, color lighter; size generally smaller except for tibia;
bullae appear smaller; palate narrower and with deeper fossa; lateral
borders of palatal fossa more nearly parallel and continuing farther
anteriorly; posterior borders of palatal fossa more nearly perpen
dicular to anterior-posterior axis; median post-palatal projection
broader9 especially at baseg and not projecting as far posteriorly«
Remarks
The light color of the available specimens is probably due to
their age 3 approximately 15 years 0 However? the differences in skull
characters between this group and specimens of thysanodes ^ both near
topotypes and from northern California) are of sufficient magnitude to
warrant describing it as a separate race 0 If intergradation with
thysanodes exists? it is probably along the California coast through
the peninsular and transverse mountain ranges in San Diego 9 Orange5
Los Angeles, and Riverside Counties0 M*. t* minimus may also be ex
pected to occur in Baja Californiao
Specimens examined
Total, 3, from the following localities: CALIFORNIA: San
Diego County: 1 mile N of Julian, 1 9 KU; La Puerta Valley, 2, KUo Figure 1 0 Distribution of the subspecies of Myotis thysanodes*
Subspecies are represented by the following letters:, A = M* t 0 thysanodes
B = Mo A 0 arizonae; C = t 0 . mexicana; D = M 0 t 0 minimus; E = M e t 0
jewelensis; F = Me Jto washingtonensis; G = Me tc aztecus* 0 * s represent localities of specimens examined» 21
100
50 50
m m
30 30
scale of miles 10 600
100 Figure 2„ Modified Dice-Leraas graphs of forearm lengths of six subspecies of Myotis thysanodeso Rectangles include the 95% confidence interals* For explanation of letters, see Figo lo LENGTH (mm) 40- 42- 44— 38 46-i - 32 A 72 BCD 115 FOREARM h Figure 3. Modified Dice-Leraas graphs of metacarpal III lengths of six subspecies of Myotis thysanodes. Rectangles include, the 95%' confidence intervalso For explanation of letters, see Fig* 1. LENGTH (mm) - 8 3 - 0 4 36 — 44-i 42- 34 - B D C B A 32 - 3 73 EAAPL III METACARPAL 115 h Figure 4. Modified Diee-Leraas graphs of tibia lengths of six subspecies of Myotis thysanodes. Rectangles include the 95% confidence intervalso For explanation of letters, see Fig* 1. LENGTH (m m) 20n 16- 14- 18- 70 109 Tl B I A 24 Figure 5„ Modified Dice-Leraas graphs of lengths of maxillary
toothrows9 breadth across upper molars, and skull lengths in six
subspecies of Myotis thysanodes. Rectangles include the 9 5 % confidence internalse For explanation of letters, see Fig, 1* LENGTH (mm) 6.4 6.0 7.0-1 16- 17- — 29 32 30 B D F E D C B A RAT ARS UPR M UPPER ACROSS BREADTH AILR TOOTH ROW MAXILLARY 3118 73 57 73 - 3 113 106 SKULL 26
Table 2. Statistical data for measurements
presented in Figures 2 , 3, 4, and 5.
Myotis thysanodes thysanodes (A)
(ft) range X + s- C
Length of fore arm 32 37.8-45.2 40.5+0.261 3.65
Length of meta carpal III 31 34.0-40.0 37.3+0.239 3.56
Length of tibia 31 14.0-16.8 15.5+0.124 4.50
Greatest length of skull . 29 15.3-16.6 15.9+0.207 6.94
Length of max illary toothrow 30 5.9-6.6 6.2+0.032 2.83
Breadth across upper molars 32 6 .1-6.8 6.35+0.038 3.37
Myotis thysanodes arizonae (B)
Length of fore arm 73 38.1-45.2 42.2+0.140 2.75
Length of meta carpal III 72 3.0-43.0 39.45+0.197 4.23
Length of tibia 70 14.4-18.6 16.5+0.113 5.76
Greatest length of skull 57 15.9-16.9 16.7+0.040 1.82
Length of max
illary toothrow 73 6 .1-6. 8 6.45+0.017 2.25
Breadth across uppermolars 73 6.2-7.1 6.7+0.022 2.76 27
Table 2 * (Continued)
Myotis thysanodes mexicana (C)
K range X ± ss C
Length of fore arm 115 39.0-44.8 41.640.106 2 .74
Length of meta carpal III 114 35.4-41.9 38.9+0.140 3.83
Length of tibia 109 13.6-18.8 16.25+0.085 5.45
Greatest length of skull 106 15.3-16.6 16.35+0.036 2.27
Length of max illary too.throw 113 6 .0 -6 .9 6.35+0.016 2.72
Breadth across upper molars 118 6 .2-7.1 6.6+0.017 2.75
Myotis thysanodes minimus CD)
Length of fore arm 3 38.0-38.8 38.3+ -
Length of meta J carpal III 2 . 36.2-37.2 36.7+ -
Length of tibia 3 17.0-18.3 17.65+
Greatest length of skull 3 15.7-16.0 15.9+ -
Length of max illary toothrow 3 6 .0 -6 . 2 6.07+ - .
Breadth across upper molars 3 6 .1-6.4 6 .2 + Table 2. (Continued)
Myotis thysanodes j ewe lens is .(E)
■N. range X +
Length of fore arm 3 39.7-40.3 40.0+
Length of meta carpal III 3 36.8-37.7 37.2+
Length of tibia 3 17.0-17.6 17.3+
Greatest length of skull 2 16.2-16.3 16.25+
Length of max illary toothrow 3 6 .3-6.4 6.33+
Breadth across upper molars 3 6.2-6.7 6.4+
Myotis thysanodes washingtonensis (F)
Length of fore arm 3 38.6-43.5 40.5+
Length of meta carpal III 2 36.7-40.3 38.5+
Length of tibia v 1 17.2
Greatest length of skull 2 16.0-16.1 16.05+
Length of max illary toothrow 2 6 .2-6.4 6.3+
Breadth across upper molars 2 6 .2 -6 . 6 6.4+ DISCUSSION
It has been suggested that there are several isolating mechanisms in operation within this species, and that these mechanisms have been in effect over a period of time sufficient to bring about the evolution
of separate geographic races 0 This isolation is thought to be due to factors related to geography, habitat, and behavioro
Geographic isolation is indicated in that Mo thysanodes lives at relatively higher elevationse Its distribution is essentially re stricted to mountain ranges related to the Rocky Mountains and the
Sierra Madres0 Populations, therefore, are prevented from exchanging genes with other populations throughout most of the r&nge, and are
essentially living on "ecological islands" 0
The habitat also acts as an isolating mechanism0 A rather moist environment is required by this species and is satisfied.by con
ditions in oak and pine forests0 A few active Fringed, myotis have been taken in drier habitats in the fall, but they were assumed to be exceptional in that most bats of this species are found dormant in caves during this time of year®
The evidence indicates that this bat is non-migratory (Table 1); this also acts as an isolating mechanism, and is probably a secondary
effect of habitat requirements0
These factors influencing populations of this species neces sarily bring about genetic isolation® Since it is apparent from the number of M® thysanodes that have been collected that population densities in the northern part of the range3 as well as in extreme
southern California, are relatively smaller (Figure 2, Table 2) 3 it seems likely that genetic drift would have the greatest effect in these groupso This is borne out when one considers that these groups are the smallest of the subspecies here recognized* M* to washingtonensis and Mo to iewe lensis apparently refute BergmamVs rule, which states that animals living in cooler environments tend to have a higher sur
face to volume ratio than those living in warmer climates0 The only area in which Bergmann* s rule appears to be in effect is in the mexicana- arizonae range, and it is here, in the widest area of sympatry, that
the greatest opportunity for gene exchange occurs0 LITERATURE CITED
Bailey, V» 1931«, • Mammals of New Mexico 0 N« Amer® Fauna, 53: 1-412, 22 pis®, 58 figs®, March 1®
Bole, B. P„. Jr® 1935, Myotis thysanodes in South Dakota® J® Mamm®, 16: 147-148®
Borell, E® and M® D,. Bryant, 1942® Mammals of. the Big Bend area of Texas„ Univ® of Calif® Publ® Zool®, 48: 1-62,
Burt, W® H® 1934. The mammals of southern Nevada, Trans® San Diego Soc® Nat® Hist®, 7: 375-427, 1 map, May, 1934®
,1938. Faunal relationships and geographic distribution of mammals in Sonora, Mexico. Univ® of Mich®, Mus® of Zool®, Misc® Publ® No. 39, Feb®. 14®
Dalquest, W= 1938. . Bats in the state of Washington. J. Mamm. 19: 211-213®
______.1953. Mammals of the mexican state of San Luis Potosi. Louisiana State University Studies, Biological Science Series No. 1: 1-229.
Deacon, J® E®, W. G® Bradley, and K®. M. Larsen® 1964. Ecological distribution of the mammals of Clark County, Charleston Mountains, Nevada®
Findley, S. S® and C. L® Jones® 1961. New United States record of the Mexican.big-eared bat® J®, Mamm® 42: 97®
Hoffmeister, D®. F® 1956® Mammals of the Graham (Pinaleno) Mountains, Arizona® Amer® Midi® Nat®, 55: 257-288.
Hooper, E„ T.^ 1941. Mammals of the lava fields and adjoining areas in Valencia County, New Mexico. , Misc® Publ®, Mus®. of Zool®, Univ. of Mich®, 51: lp47®
Ingles, L® G® 1958. Mammals of California, Stanford Univ® Press,.258 PP°
Jones, J® K®, Jr® and 0® L. Webb.® 1953. ■ Myotis thysanodes thysanodes is Idaho® J. Mamm®, 34: 122®
Krutzsch, P® H® and T® A® Vaughan, 1955® Additional, data on the bacula of North American bats® J® Mamm,, 36: 96-100. 32
Hall, E. R. and K, R. Kelson. 1959. The mammals of North America, vol. 1. The Ronald Press Company, New York. 546 pp.
. and B 0 Villa-R. 1949. An annotated check list of the mammals of Michoacan, Mexico. Univ. Kansas Publ., Mus. Nat. Hist., 1: 431-472.
Maslin, T. P., Jr. .1938. Fringed-tailed.bat in British Columbia. J. Mamm. 19: 373.
Miller, G. S. 1897. Revision of the North American bats of the family yespertilionidae. U. S. Dept. Agri., Div. Biol. Surv=, N. Amer. Fauna, 13: 1-140,
______. and G. M. Allen. 1938. The American bats of the genera Mvotis and Pizonvx. U. S. Nat. Mus., Bull. No. 1 4 4 , 218 pp.
Swarth, H. S. 1929. The faunal areas of southern Arizona: . a study in animal distribution. Proc. Calif. Acad. Sci. 18: 267-383.
Walker, A. 1942. The fringed bat in Oregon. The Murrelet, 23: 62.