Geographic Variation in the Bahamian Brown Racer, Alsophis Vudii A

Geographic Variation in the Bahamian Brown Racer,

Alsophis Vudii

A thesis presented to

the faculty of

the College of Arts and Sciences of Ohio University

In partial fulfillment

of the requirements for the degree

Master of Science

Christina Wieg

June 2009

Geographic Variation in the Bahamian Brown Racer,

Alsophis Vudii

CHRISTINA WIEG

has been approved for

the Program of Environmental Studies

and the College of Arts and Sciences by

Matthew W. White

Associate Professor of Biological Science

Benjamin M. Ogles

Dean, College of Arts and Sciences Abstract

WIEG, CHRISTINA, M.S., June 2009, Environmental Studies

GEOGRAPHIC VARIATION IN THE BAHAMIAN BROWN RACER, ALSOPHIS

VUDII (48 pp.)

Director of Thesis: Matthew M. White

Nine meristic and fourteen morphometric characters were examined to determine

geographic variation in the five subspecies of the insular snake species, Alsophis vudii.

In addition, museum specimens from the closely derived species Alsophis cantherigerus were examined. Canonical discriminate analysis determined that, based on the morphological data, significant differences were observed among subspecies. However, significant differences were also observed between island populations. My results suggest that the current subspecies designations oversimplify the variation within the species and are not an adequate reflection of variation present among the island populations. Additional research is required in order to determine the causes of the observed variation within the species. Possible explanations for observed variation may include multiple colonization events or environmental variation among islands.

Approved:

Matthew M. White

Associate Professor of Biological Sciences Dedication

I dedicate this work to my husband, Rick Perkins. Without his constant support my goals would have never become a reality. I would also like to dedicate this work to my lovely

daughter, Raven Perkins. I never knew unconditional love until I looked into her eyes. 5

Acknowledgments

I would like to thank my committee members, Matthew W. White, Donald B.

Miles, and James Dyer for their advice and assistance on this project. I would especially like to thank advisor Dr. White for his support, patience, and understanding during the development of this project. I would also like to thank committee member Dr. Miles for his assistance in the statistical analysis of the data and the use of his laboratory and Scott

Moody for his guidance in the development of the methods. Special thanks to Gene

Mapes and Cheryl Hanzel for their assistance. Funding for the project was provided by

Masters in Environmental Studies Program, and a Graduate Student Senate Grant.

Specimens were provided by the Natural History Museum at the University of Kansas and the Museum of Comparative Zoology at Harvard University. 6

Table of Contents

Abstract ...... 3

Dedication ...... 4

Acknowledgments...... 5

List of Tables ...... 7

List of Figures ...... 8

Introduction ...... 9

Systematics of Alsophis vudii ...... 11

Materials and Methods ...... 14

Statistical Analysis ...... 15

Results ...... 17

Morphological Variables ...... 17

Meristic Variation ...... 23

Phylogenetic Analysis ...... 27

Discussion ...... 31

References ...... 36

Appendix A: Institutional Abbreviations ...... 39

Appendix B. Sample size (N), means, and standard deviations (SD) for 14 morphological characters by subspecies, island, and sex...... 41

Appendix C: Sample size (N), means, and standard deviations (SD) for 5 meristic characters by subspecies, island, and sex ...... 45

List of Tables

Table Page

1. Description of and codes used for meristic and morphometric variables...... 14

2. Mahalanobis distance for squared distance to subspecies for morpholmetric data .... 18

3. Results from the CDA using subspecies as a grouping variable...... 18

4. The five canonical correlation structures of the morphometric characteristics ...... 20

5. Mahalanobis distance for squared distance to subspecies of A. vudii for meristic

characters...... 23

6. The canonical correlation structure of the meristic characteristics from subspecies

designations of A. vudii ...... 24

7. The canonical structures of the meristic characteristics ...... 26 8

List of Figures

Figure Page

1. Distribution of the five subspecies of Alsophis vudii: 1) A.v. vudii 2) A. v. aterrimus

3) A. v. picticeps 4) A. v. raineyi 5) A. v. utowanae...... 12

2. CDA by of morphometric data by island populations ...... 18

3. Cluster analysis based on class means from the Canonical Variates Analysis of

morphological variables of the island populations...... 21

4. Cluster Analysis based on shape variation from the Canonical Variates Analysis of

morphological variables of the island populations ...... 22

5. CDA by of meristic data by island populations...... 25

6. Cluster analysis based on class means from the Canonical Variates Analysis of meristic variables of the island populations……………………………………………..27

7. Phylogenetic analysis using the continuous maximum likelihood based on means for the morphological variables of the island populations of A. vudii………………………………………………….………………………………….28

8. Phylogenetic Analyisis of the continous maximum likelihood using the means of the Meristic data from the island popultations………………………………………………30

Introduction

Geographic variation within species has been the focus of many studies (Endler,

1977; Pearson et al., 2002). Patterns of variation associated with environmental heterogeneity can allow the grouping of local populations into systematic categories.

More importantly, studies of geographic variation can provide insight into the process of

differentiation and speciation. The presence of geographic variation can be a potential

isolating mechanism which may further the separation between the two populations

(Mayr, 1999).

The isolation of insular species results in greater limitation in gene flow and is often the result of founder effect (MacArthur and Wilson, 1967). As a result, insular species often express a greater degree of geographic variation among populations and between island populations and mainland populations. As a result, biologists have long had an interest in studying the geographic variation among populations of island species.

A wide variety of geographic variation has been observed among insular reptile species. Much of the observed variations have resulted in subspecies designations.

However, the usefulness of subspecies designation in describing the actual variation observed among a species has been questioned (Barrowclough, 1982). The designation of a subspecies portrays a phenotypic uniformity across an area of distribution. However, a frequently observed pattern of variation consists of a lack of concordance of clines in different characters (independent geographic variation), reoccurrence of characters in several geographic areas (polytopic subspecies), and every population differing in some

character (microgeographic races) (Wilson and Brown, 1953). Therefore, subspecies 10 designations do not tend to accurately reflect the geographic variation present within a species. In addition, subspecies designations were often based on observed variation in a single specimen or variation as a result of a damaged or discolored specimen (Mayr,

1982). Such designations are now being revisited to better determine the true pattern of geographic variation present. Manier (2004) examined such a case in the four subspecies of long-nosed snake, Rhinocheilus lecontei. The study examined meristic, morphometric, and color pattern characteristics among the three mainland and one island populations of

R. lecontei. No one subspecies was consistently divergent in all analyses suggesting that mainland populations did not warrant subspecies status. However the island subspecies differed significantly in size compared to mainland populations (Manier, 2004).

In addition to providing systematic information for classification, many studies of geographic variation have provided insight into the possible effects of environmental factors and geographic patterns in morphology. Associations between morphology in reptile species and environmental variables, such as climate, vegetation, and soil type have been examined. Extensive studies of Anolis lizard species indicate that natural selection due to habitat differentiation has influenced such morphological characters as limb length (Calsbeek et al., 2007).

Variation in meristic characteristics of reptiles has also been influenced by environmental factors. A number of studies indicate that ecological variables such as precipitation, temperature, and elevation are correlated with scale count in reptiles

(Calsbeek et al., 2006). Scales may play a crucial role in reptilian water balance

(Alibardi, 2003) and influence thermoregulation (Ruben and Jones, 2000). Scale counts 11 in Bahamas Anolis lizard species increase with increasing precipitation and decreasing temperature in arid habitats, suggesting that natural selection due to environmental factors are at work (Calsbeek et al., 2006).

The purpose of this study is to reexamine the five subspecies of the insular snake species, Alsophis vudii to determine the true extent of geographic variation present within the species. This study provides additional information into the possible origin and diversification of a little known snake species.

Systematics of Alsophis vudii

Alsophis vudii is an endemic colubrid snake of the Bahamas Archipelago

comprised of five described subspecies with allopatric distributions (A. vudii vudii, A. v.

aterrimus, A. v. picticeps, A. v. raineyi, and A. v. utowanae; Figure 1; Schwartz &

Henderson, 1991). Alsophis vudii species was first described by Cope (1863) and

Barbour and Shreve (1935) and Conant (1937) subsequently designated subspecies. The

five subspecies descriptions were largely based on variation in coloration and scale count.

Barbour and Shreve (1935) diagnosed A. v. aterrimus from A. v. vudii based on coloration

difference alone. However, coloration is highly variable within the species (Schwartz &

Henderson, 1991) and may be a poor choice of character upon which to base a subspecies

description. 12

Figure 1. Distribution of the five subspecies of Alsophis vudii: 1) A. v. vudii 2) A. v. aterrimus 3) A. v. picticeps 4) A. v. raineyi 5) A. v. utowanae.

Problems arise from using color variation and a limited number of meristic characters to designate subspecies in a small sample size. Some of the subspecies were described from only a few specimens. This would make estimates of variation less robust. In the case of A. v. picticeps, the subspecies description was based on a single specimen (Conant, 1937).

Maglio (1970) examined the osteological and himipenial morphology of thirty- three species of Xenodontine snakes in the West Indies, including the genus Alsophis.

Though the primary focus of the research was to examine the subfamily Xenodontine as a 13 whole, the study established several differences among the subspecies of A. vudii not previously noted. Alsophis v. utowanae was found to differ from the other subspecies in several characters, including nasal bone shape and dental formula. Although only two specimens of A. v. utowanae were available for the study, Maglio (1970) suggested that these differences may be more than subspecific. He suggested retaining A. v. utowanae as a subspecies of A. vudii until additional specimens were available and the range of variation better known. In addition to noting differences between subspecies, Maglio’s research indicated that West Indies snake species (including Alsophis) are South

American in origin and arose by multiple colonization events from the mainland.

A number of hypotheses may be provided to explain observed morphological variation among the island populations of A. vudii. Diversity of local environmental factors such as habitat, prey availability, or predation can affect population differentiation. Alternatively, morphological variation may be a result of dispersal, such as over water dispersal patterns associated with ocean currents. The presence or absence of past land bridge connections during the Pleistocene may have also constricted gene flow, resulting in interpopulation morphological variation.

I used a multivariate approach to determine patterns of geographic variation in the insular species A. vudii. The objectives of this research were i) to examine if the current subspecies designations adequately reflect the morphological variation present among the species and ii) to better understand the geographic structuring of the species among the island populations.

Materials and Methods

A total of 216 preserved museum specimens were examined from throughout the

geographical distribution of A. vudii in the Bahamas, and included representatives of all five subspecies. In addition, four preserved specimens from the species Alsophis cantherigerus adspers and 27 preserved specimens from the species A. c. caymanus were examined. These latter two species were used as outgroups. Institutions from which the specimens were obtained and corresponding catalogue numbers are listed in the

Appendix.

Nine meristic characters and fourteen morphometric characters were measured

(Table 1). Digital calipers were used to measure the twelve head characters to the nearest

0.01mm. Snout-vent length (SVL) and tail length (TL) were measured using a meter tape to the nearest 0.1 mm.

Table 1. Description of and codes used for meristic and morphometric variables. Variable Code Meristic Number of supralabial scales SUPR Number of infralabial scales INFR Number of preocular scales PREO Number of postocular scales POST Number of temporal scales TEMP Number of loreal scales LORE Number of subcaudal scale pairs SUBC Number of ventral scales VENT Number of dorsal scales at midbody DORS

Table 1 continued Morphometric Snout-vent length SVL Tail length TL Head width HW Head length HL Interocular length IO Internarial length IN Naris-rostrum length NR Eye-naris length EN Eye diameter ED Eye-jaw length EJ Frontal width FW Frontal length FL Parietal width PW Parietal length PL

Statistical Analysis

Specimens with broken tails, damaged heads, and SVL less than 30.5 cm were not used in the data analysis. Means and standard deviations for the morphometric and meristic data were determined. All morphometric variables were log10 transformed to ensure multivariate normality. All analyses were conducted using the SAS 9.0 or JMP

5.0 software packages.

To determine whether there were significant morphological differences among the currently recognized subspecies, the fourteen log transformed morphometric characters were used in a Canonical Discriminant Analysis (CDA). Similar CDA was conducted on meristic data. The null hypothesis was the subspecies did not differ in morphology. A second goal was to determine whether there was statistically significant differentiation among the island populations. CDA is analogous to a multiway discriminant analysis. In this analysis, I used either subspecies or island population as a classification (i.e., 16 grouping variable). The analysis determines whether group membership based on the morphological and meristic data matches the a priori membership. A secondary goal of the analysis was to identify the key morphological traits that best separates the groups.

In order to visualize group similarities, I applied a cluster analysis based on the first five axes from the CDA. I used UPGMA cluster analysis of the means from the canonical analysis to determine the relationships of the subspecies based on morphological and meristic variation. I also examined the similarity of island populations (i.e., evidence of geographic structuring) based on the morphological and meristic data.

The preceding analyses were ahistorical in nature. Hence, to determine the phylogenetic relationships among the island populations, I applied a continuous maximum likelihood analysis using the means from the morphometric and meristic characters. Each character set was analyzed separately using the CONTML program in the PHYLIP 3.65 Package.

Results

Morphological Variables

Sample size, mean, and standard deviations of the morphological variables

examined for each subspecies, island, and sex are presented in the Appendix.

CDA determined that significant differences were detected when subspecies was

used as the classification. In addition, when examining the analysis based on island

populations, significant differences were also observed among island populations (Figure

2).

Figure 2. CDA of morphometric data by island populations 18

I calculated Mahalanobis D2 values between all possible pairs of subspecies

(Table 2). All subspecies were significantly different in their morphology. A CDA confirmed the distance analysis in that 5 axes significantly separated the subspecies

(Table 3).

Table 2. Mahalanobis squared distance to subspecies for morphometric data. subspecies adspers aterrimus caymanus picticeps raineyi utowanae vudii adspers 0 20.56 16.60 22.41 19.27 20.80 14.84 aterrimus 20.56 0 11.12 14.88 5.50 8.68 6.80 caymanus 16.60 11.12 0 5.19 7.93 8.26 4.23 picticeps 22.41 14.88 5.19 0 7.04 11.66 6.48 raineyi 19.27 5.50 7.93 7.04 0 6.24 4.49 utowanae 20.80 8.68 8.26 11.66 6.24 0 6.17 Vudii 14.84 6.80 4.23 6.48 4.49 6.17 0

Table 3. Results from the CDA using subspecies as a grouping variable. Coefficients refered to in the text are highlighted in bold.

Variables CAN 1 CAN 2 CAN 3 CAN 4 CAN 5 SVL 0.85 -0.19 -0.31 -0.37 0.12 TL 0.48 -0.60 -0.21 -0.34 0.43 HW 0.81 -0.02 -0.22 -0.30 0.45 HL 0.83 -0.05 -0.21 -0.11 0.50 IO 0.83 -0.05 -0.08 -0.26 0.48 IN 0.87 -0.10 0.06 -0.20 0.40 NR 0.40 -0.23 -0.29 -0.58 0.58 EN 0.95 0.24 0.08 -0.07 0.15 ED 0.25 0.42 -0.83 0.13 0.23 EJ 0.83 -0.21 -0.45 0.08 0.25 FW 0.95 -0.15 0.08 -0.04 0.26 19

Table 3 continued FL 0.79 0.52 -0.05 0.01 0.32 PW 0.58 -0.24 -0.17 -0.51 0.55 PL 0.56 -0.60 -0.16 0.14 0.51 Eigenvalues 0.74 0.52 0.36 0.25 0.20

In the CDA of subspecies populations, four axes explained 86% of the total

morphological variations among the subspecies (CC1 = 0.65, P<0.0001; CC2 = 0.58,

P<0.0001; CC3 = 0.52, P<0.0001; CC4 = 0.45, P<0.0001) (Table 3). The morphometric

characteristics responsible for CAN 1 include all measured characters except naris- rostrum length and eye diameter. CAN 1 reflects the changes in morphological variables

due to size differences in individuals. The predominant variables responsible for CAN 2

included tail length, frontal length, and parietal length. CAN 3 influential variables

include both eye diameter and eye-jaw length. Naris-rostrum length and parietal width

dominated CAN 4.

In the CDA of island populations, five axes explained 84% of the total

morphological variations among the island populations (CC1 = 0.75, P<0.0001; CC2 =

0.67, P<0.0001, CC3 = 0.62; P<0.0001; CC4 = 0.55, P<0.0001; CC5 = 0.48, P = 0.0048)

(Table 4). The morphometric characteristics responsible for CAN 1 included snout-vent

length, head width, interocular length, internarial length, naris-rostrum length, eye-naris

length, eye diameter, frontal width, frontal length, and parietal width. CAN 1 reflects the

changes in morphological variables due to size differences in individuals. The

predominant variables responsible for CAN 2 included both the eye-naris length and

frontal width. CAN 3 influential variables were the snout-vent length, head width, head 20 length, interocular length, internarial length, eye-jaw length, and the parietal length. The distance between eyes and eye to jaw were found to be important for CAN 4. CAN 5 was largely represented by the variables eye-naris length and eye diameter.

Table 4. The five canonical correlation structures of the morphometric characteristics.

Coefficients referred to in text are highlighted in bold.

Variables CAN 1 CAN 2 CAN 3 CAN 4 CAN 5 SVL 0.49 0.31 -0.60 0.30 -0.19 TL 0.17 0.34 -0.11 -0.03 0.13 HW 0.59 0.29 -0.53 0.27 -0.04 HL 0.37 0.25 -0.52 0.41 -0.14 IO 0.68 0.27 -0.50 0.13 -0.06 IN 0.63 0.32 -0.50 0.13 -0.19 NR 0.49 0.05 -0.41 -0.10 0.05 EN 0.48 0.52 -0.20 0.42 -0.27 ED 0.66 -0.17 -0.21 0.52 0.41 EJ 0.23 0.43 -0.61 0.49 0.07 FW 0.49 0.71 -0.34 0.04 -0.03 FL 0.70 0.36 -0.03 0.43 -0.07 PW 0.68 -0.05 -0.38 0.27 -0.19 PL -0.14 0.27 -0.65 0.29 -0.11 Eigenvalues 1.31 0.82 0.63 0.44 0.29

A cluster analysis based on the class means from the canonical variates analysis of the morphological variables in the island subspecies populations is presented in Figure

3. The outgroup species Alsophis cantherigerus adspers on Cuba clustered separately

from the Alsophis vudii species/populations as would be expected. The two island

populations of A. v. aterrimus group together, as do the two island populations of A. v.

raineyi. However, Alsophis cantherigerus caymanus from the Grand Caymans is nested 21 within A. v. vudii from Cat Island. In addition, A. v. utowanae from Great Inaugua clusters with A. v. vudii from Eleuthera. The cluster analysis seems to suggest that though some subspecies designations such as aterrimus and raineyi seems to group together as would be expected, other subspecies do not cluster. Alsophis vudii appears to have a different pattern of variations than what would be suggested by subspecies designations. In addition A. cantherigerus caymanus seems to be morphologically more similar to A. vudii than the sister subspecies A. cantherigerus adspers from Cuba.

Figure 3. Cluster analysis based on class means from the Canonical Variates Analysis of

morphological variables of the island populations 22

Shape Variation

A cluster analysis based on shape variation from the Canonical Variates Analysis of the morphological variables in the island subspecies populations was also preformed

(Figure 4). Results were similar to cluster analysis based on class means from the

Canonical Variates Analysis of morphological variables of the island populations. One exception was the two island populations of A. v. raineyi did not group closely together.

Instead all island populations of A. v. vudii except A. v. vudii from Cat Island nested within the island populations of A. v. raineyi.

Figure 4. Cluster analysis based on shape variation from the Canonical Variates

Analysis of morphological variables of the island populations

Meristic Variation

The same analysis is presented for the results from the data containing the meristic variables. Sample size, mean, and standard deviations of the meristic variables examined for each subspecies, island, and sex are presented in the Appendix. CDA of meristic data analyzed by subspecies designation showed that A. v. picticeps is distinct in that it differs significantly from all other subspecies designations and the two A. cantherigerus subspecies. All other subspecies and the two A. cantherigerus subspecies did not differ significantly from each other (Table 5).

Table 5. Mahalanobis distance for squared distance to subspecies of A. vudii for meristic characters. subspecies adspers aterrimus caymanus picticeps raineyi utowanae vudii adspers 0 1.12 0.13 11.37 0.14 0.31 1.05 aterrimus 1.12 0 0.56 12.12 0.89 1.85 0.36 caymanus 0.13 0.56 0 11.00 1.19 0.49 0.56 picticeps 11.37 12.12 11.00 0 10.91 11.72 8.45 raineyi 0.14 0.89 0.19 10.91 0 0.76 0.75 utowanae 0.31 1.85 0.49 11.72 0.76 0 1.81 vudii 1.05 0.36 0.56 8.45 0.75 1.81 0

In the CDA of subspecies, one axes explained 85% of the total meristic variations among the subspecies populations (CC1 = 0.67, P<0.0001) (Table 6). The meristic characteristics responsible for CAN 1 included the right temporal, left temporal, number 24 of dorsal scales at midbody, total number of ventral scales, and total number of subcaudal scales.

Table 6. The canonical correlation structure of the meristic characteristics from

subspecies designations of A. vudii.

Variables CAN 1 Right TEMP 1.00

Left TEMP 1.00 DORS 0.98 VENT -0.13 SUBC -0.48

CDA of meristic data analyzed by island populations indicate that significant variations

are present between different island populations; even those island populations that

shared the same subspecies designations (Figure 5). The island population of Bimini

that is comprised of the subspecies A. v. picticeps was found to be significantly different

than all other island populations based on the meristic data.

Figure 5. CDA of meristic data by island populations.

In the CDA of island populations, two axes explained 80% of the total meristic variations among the island populations (CC1α = 0.71, P<0.0001; CC2α =0.49, P=

0.0022) (Table 7). The meristic characteristics responsible for CAN 1 included the right temporal, left temporal, number of dorsal scales at midbody, total number of ventral scales, and total number of subcaudal scales. The predominant variables responsible for

CAN 2 were identical to CAN1 excluding the left temporal.

Table 7. The canonical structures of the meristic characteristics. Values for the two significant axes are presented. Variables CAN 1 CAN 2 Right TEMP 0.97 0.08

Left TEMP 0.99 -0.01 DORS 0.83 0.16 VENT -0.18 0.95 SUBC -0.06 0.23

Results of the Cluster Analysis based on the class means from the canonical

variates analysis of the meristic variables in the island populations is presented in Figure

6. Alsophis v. picticeps grouped separately from all other island populations of Alsophis v. Much of the other island populations with the same subspecies designations did not cluster closely together. The outlier species Alsophis cantherigerus adspers on Cuba clusters with the Acklins island population of Alsophis v. raineyi. The cluster analysis seems to reflect that the clustering of the meristic data based on island populations is not solely dependent on island proximity or to the subspecies designations.

Figure 6. Cluster analysis based on class means from the Canonical Variates Analysis of meristic variables of the island populations

Phylogenetic Analysis

The phylogenetic analysis using continuous maximum likelihood based on means for morphological data from the island populations is represented in Figure 7. The analysis indicates that some island populations appear to be closely grouped by their shared subspecies designations, such as A. v. aterrimus. However, A. vudii subspecies appear to group with one another and other subspecies throughout the analysis. These results, once again, suggest that the A. v. vudii subspecies designation does not adequately reflect the morphological variation found within the island populations. 28

Figure 7. Phylogenetic analysis using the continuous maximum likelihood based on means for the morphological variables of the island populations of A. vudii.

The phylogenetic analysis using continuous maximum likelihood based on means for the meristic data from the island populations is presented in Figure 8. The analysis indicates that many of the island populations group with one another regardless of proximity of the islands or the subspecies designations. The A. c. adspers species was separated out from the other A. vudii species, as would be expected. A. v. utowanae and

A. v. raineyi also separated out from all other A. vudii species and A. c. caymanus. 30

Figure 8. Phylogenetic analyisis of the continous maximum likelood using the means of the meristic data from the island populations of A. vudii.

Discussion

These results demonstrate considerable variation in morphology among the island populations of A. vudii. The pattern of differentiation appears to have two components.

Subspecies are statistically distinguishable mainly in linear morphology, but there is also considerable variation among islands. Neither the size nor shape analysis explained the variation observed among subspecies. A complex pattern of inter-island differentiation was evident in the linear morphology. Analysis of the meristic characteristics did not show subspecific or island differentiation.

Differentiation observed in A. v. vudii does not appear to be consistent with subspecies designations. Alsophis v. vudii island populations did not uniformly cluster together. Alsophis v. vudii is found on eight major islands; however sufficient data were only available for seven of the islands. Four island populations of A. v. vudii cluster

with A. v. raineyi based on morphological characters. The A. v. vudii population on Cat

Island clusters with the Cayman Island species A. caymani. Alsophis v. vudii on Little

Ragged and Eleuthera cluster with A. v. utowanae on Great Inaugua. Therefore, due to

the proximity of Little Ragged Island to Great Inuagua Island the Little Ragged

population of A. v. vudii appears to be more similar in morphology to the subspecies A. v.

utowanae. The similarity between the A. v. vudii Eleuthera island population and the A.

v. utowanae may be a reflection of convergence. Instead of sharing common ancestors,

these two island populations may be morphological similar as a result of common

adaptive solutions to similar environmental pressures such as predators, vegetation, or

prey availability. 32

Alsophis v. utowanae differs significantly in nasal bone shape and dental formula

(Maglio, 1970). Maglio (1970) suggested that the differences may be more than subspecific. However, the results of the morphological analysis did not reflect this magnitude of variation among the subspecies population.

Several subspecies designations were concordant with inter-island variation. A. v. raineyi and A. v. aterrimus, both found on two islands, cluster with their respective subspecies designations in the cluster analysis. In this case, the subspecies designations appear to reflect the morphological variation found in the island populations.

The current subspecies designations may oversimplify the variation within the species and are not an adequate reflection of variation present among the island populations. The cause for the observed variation among island populations of A. vudii may be due to multiple factors. Geographic proximity did not correlate with morphological similarity among populations. This suggests that the observed variation may be a result of multiple colonization events which coincides with Maglio’s findings

(1970). However, several molecular studies (Hedges et al., 2009; Crother & Hillis,

1995; Crother 1999; Vidal et al., 2000; Hass et al. 2001; Pinou et al. 2004) have contradicted Maglio’s assertion of non-monophyly of the West Indian species and multiple colonization events from the mainland.

The timing, origin, and mode of possible colonization events of West Indies fauna has been the subject of much debate. The complex geological history of the West Indies allows for several modes of dispersal for colonization including both overwater dispersal and land bridges. However, the lack of a complex fauna in the West Indies with poor 33 representation of the higher levels of taxonomy and large adaptive radiation of certain groups indicates that over-water dispersal was the primary mechanism for the origin of the terrestrial vertebrates in the West Indies (Hedges, 1996a,b).

Studies examining timing of these colonization events suggest that the dispersal of West Indian vertebrates occurred throughout the Cenozoic and not during one time period. Hass et al. (2001) examined the relationship and divergence times of several

West Indian amphibians and reptiles, including several members of the family

Colubridae. They suggested that many of the West Indian Xenodontine species had diverged within the last 12 million years with a probable origin from South America.

Examination of osteological and hemipenial morphology suggests that A. vudii is a member of the cantherigerus species assemblage which appeared to originate in South and/or Central America and dispersed into the West Indies (Maglio, 1970). The genus

Alsophis probably originated from a species similar to the Cuban A. cantherigerus. This species could have dispersed from Cuba to colonize Jamaica (A. ater), the Little and

Great Bahama banks (A. vudii), and Hispaniola (A. melanichnus) (Maglio, 1970). Similar results have been observed in phylogenetic studies of the Xenodontine (Hedges et al.,

2009; Cadle, 1984).

Current and historical ocean currents support the origin of West Indian reptiles and amphibians from South America. The Atlantic current flowed from southeast to northwest throughout the Cenozoic (60 mya) to the present. However, the extent to which Alsophis vudii utilizes over water dispersal is not known. This species has been observed to take to sea and colonize nearby islands (Knapp, 2000). 34

Environmental variation among islands may also contribute to the variation observed among populations of A. vudii. The plant communities of the Bahamas’ archipelago are diverse, providing a variety of habitats. The coastline consists of sandy beaches, jagged rocks, and mangrove communities. On the fringes of the coast lies the coastal coppice community which contains large shrubs, trees that reach five meters in height, and a diverse assemblage of epiphytes. Further inland can be found the interior coppice community and on the islands of Grand Bahama, Abaco, New Providence, and

Andros the pineland community. Additional habitats include savanna, scrub, freshwater swamp, and saltwater marsh or "swash"(Nickrent et al., 1988).

Though little literature is available on the natural history of A. vudii, it is clear that

A. vudii utilizes a variety of these habitats. It can be found in both xerophytic and mesophytic environments. Specimens have been acquired from coastal mangroves, pinewoods, beaches, grassy areas, as well as areas of human habitation. They are predominantly ground dwelling, but have been observed climbing in bushes (Schwartz &

Henderson, 1991).

A description of the habitat in which the specimens used in this study were collected was not available. Information on prey availability and preferences was also not available for populations. Further, detailed data on island specific ground cover were not available. Additional research is needed to determine if the variation among island populations is correlated to habitat type, prey availability or preferences.

The morphological variation in a species may not be direct result of a single factor. Anolis lizards in the Bahamas archipelago have long been a classic example of 35 adaptive radiation of a species (Calsbeek et al, 2007; Calsbeek et al., 2006). However, a

2003 study indicated that the Anolis lizard’s gene flow from island to island is congruent with the prevailing ocean currents, supporting that overwater dispersal frequently occurs

(Calsbeek & Smith, 2003). The study highlights that adaptive diversification may be disrupted by constant influx of gene flow from other islands. For this reason, the examination of gene flow of A. vudii would provide additional information to further understand the morphology observed amongst the island populations.

Current analysis of available data suggests that the variation in morphology amongst the A. vudii species is not reflective of current subspecies designations. Further evaluation of influencing factors, such as habitat use and diet, may shed light on possible mechanisms of adaptive radiation, leading to morphological variation. Large sample sizes for some subspecies were not available for this study. With similar results of additional specimens, the recommendation would be to eliminate the subspecies designations in favor of a single polymorphic A. vudii species.

References

Alibardi, L. 2003. Adaptation to the land: the skin of reptiles in comparison to that of amphibians and endotherm amniotes. Journal of Exp. Zoology. Part B-Mol. Dev. Evolution. 298B:12-41. Barbour, T. and B. Shreve. 1935. Concerning some Bahamian reptiles, with notes on the fauna. Proceedings of the Boston Society of Natural History. 40:347-366. Barrowclough, G.F. 1982. Geographic Variation, Predictiveness, and Subspecies. Auk. 99:601-603. Cadle, J.E. 1984. Molecular systematics of neotropical Xenodontine snakes: I. South America Xenodontines. Herpetologica. 40:8-20. Calsbeek, R., T.B. Smith, and C. Bardeleben. 2007. Intraspecific variation in Anolis sagrei mirrors the adaptive radiation of Greater Antillean anoles. Biological Journal of the Linnean Society. 90:189-199. Calsbeek, R. and T.B. Smith. 2003. Ocean currents mediate evolution in island lizards. Nature. 426:552-555. Calsbeek, R., J.H. Knouft, and T.B. Smith. 2006. Variation in scale numbers is consistent with ecologically based natural selection acting within and between lizard species. Evolutionary Ecology. 20:377-394. Crother, B.I. 1999. Phylogenetic relationships among West Indian Xenodontine snakes (Serpentes; Colubridae) with comments on the phylogeny of some mainland Xenodontines. Contemporary Herpetology. 1999:1-21. Crother, B.I. and D.M. Hillis. 1995. Nuclear ribosomal DNA restriction sites, phylogenetic information, and the phylogeny of some Xenodontine (Colubridae) snakes. Journal of Herpetology. 29:316-320. Conant, R. 1937. Alsophis from new islands with the description of a new subspecies. Proceedings of the New England Zoological Club. XVI:81-83. Endler, J.A. 1977. Geographic Variation, Speciation, and Clines. Princeton, NJ: Princeton University Press. 37

Hass, C.A., L.R. Maxson, and S.B.Hedges. 2001. Relationships and divergence times of West Indian amphibians and reptiles: Insights from albumin immunology. Pp. 157-174. In C.A. Woods & F.E. Sergile (eds), Biogeography of the West Indies: Patterns and Perspectives. 2nd Edition, CRC Press. Hedges, S.B., A. Couloux, and N. Vidal. 2009. Molecular phylogeny, classification, and biogeography of West Indian racer snakes of the Tribe Alsophiini (Squamata, Dipsadidae, Xenodontinae). Zootaxa. 2067:1-28. Hedges, S.B. 1996a. Historical biogeography of West Indian vertebrates. Annual Review of Ecology and Systematics. 27:163-196. Hedges, S.B. 1996b. The origin of West Indian amphibians and reptiles. Pp. 95-127 in Powell, R. and R. Henderson (eds.). Contributions to West Indian Herpetology: A Tribute to Albert Schwartz. Society for the Study of Amphibians and Reptiles, Ithaca, New York. Knapp, C. 2000. Alsophis vudii (Bahamian Brown Racer). Overwater Dispersal. Herpetological Review. 31:244. MacArthur, R.H., and E.O. Wilson. 1967. The Theory of Island Biogeography. Princeton University Press, Princeton. NJ. Maglio, J.M. 1970. West Indian Xenodontine Colubrid Snakes: Their Probable Origin, Phylogeny, and Zoogeography. Bulletin of the Museum of Comparative Zoology. 141:1-54. Manier, M.K. 2004. Geographic variation in the long-nosed snake, Rhinocheileis lecontei (Colubridae): beyond the subspecies debate. Biological Journal of the Linnean Society. 83:65-85. Mayr, E. 1982. Of what use are subspecies? Auk. 99:608-609. Mayr, E. 1999. Systematics and the Origin of Species from the Viewpoint of a Zoologist. Massachusetts: Harvard University Press. Nickrent, D.L., W.H. Eshbaugh, and T.K. Wilson. 1988. The Vascular Flora of Andros Island, Bahamas. Iowa: Kendall/Hunt Publishing Company. 38

Pearson, D, R. Shine, and A. Williams. 2002. Geographic variation in sexual size dimorphism within a single snake species (Morelia spilota, Pythonidae). Oecologia. 131:418-426. Pinou, T., S. Vicario, M. Marschner, and A. Caccone. 2004. Relict snakes of North America and their relationships within caenophidia, using likelihood-based Bayesian methods o mitochondrial sequences. Molecular Phylogenetics and Evolution. 32:563-574. Ruben, J.A. and T.D. Jones. 2000. Selective factors associated with the origin of fur and feathers. Am. Zool. 40:585-596. Schwartz, A. and R.W. Henderson. 1991. Amphibians and Reptiles of the West Indies: Descriptions, Distribution, and Natural History. Florida: University of Florida. Vidal, N., S.G. Kindl, A. Wong, and S.B. Hedges. 2000. Phylogenetic relationships of xenodontine snakes inferred from 12S and 16S ribosomal RNA sequences. Molecular Phylogenetics and Evolution. 14:389-402. Wilson, E.O. and W.L.J. Brown. 1953. The subspecific concept and its taxonomic application. Systematic Zoology. 2:97-111. 39

Appendix A: Institutional Abbreviations

Institutional abbreviations

KA Museum of Natural History, Kansas University HA Museum of Comparative Zoology, Harvard University

Specimens Examined

Alsophis vudii vudii Andros ( HA 5820, HA 6954, KA 267361, KA 267362, KA 267362, KA 267363, KA 267364, KA 267365, KA 267366, KA 267367, KA 267368, KA 267369, KA 267370, KA 267371, KA 267372, KA 267373, KA 267378, KA 267379, KA 267380, KA 267381, KA 267382, KA 267383, KA 267384, KA 267385, KA 267394, KA 267398, KA 267399), Berry ( KA 267403), Cat ( HA 162043; HA 163172; HA 163173; HA 163174; HA 171472; HA 171490; HA 171544; HA 173182; HA 39491; HA 39492, HA 39493; HA 39494; HA 39495; HA 39496; HA 39497; HA 39498; HA 39499; HA 39500; HA 39501, HA 39502; HA 39503; HA 39504; HA 39505; HA 39506; HA 39507; HA 39508; HA 39509; HA 39510; HA 39511; HA 39512; HA 39513; HA 39514; HA 39515; KA 267289, KA 267290; KA 267291; KA 267292; KA 267293; KA 267294; KA 267295; KA 267296; KA 267297; KA 267298; KA 267299), Eleuthera ( HA 96072, HA 96073, HA 96074, HA 96075; KA 267307; KA 267308; KA 267309; KA 267310; KA 267311; KA 267312; KA 267313; KA 267314; KA 267315; KA 267316; KA 267325; KA 267326; KA 267327; KA 267328; KA 267329; KA 267408; KA 267409; KA 267410; KA 267411, KA 267412; KA 267413; KA 267414; KA 267415), Exuma (HA 141687, KA 267330, KA 267331, KA 267332, KA 267333, KA 267334), Little Ragged (KA 267354, KA 267355, KA 267356, KA 267357, KA 267358, KA 267359, KA 267360), Long (HA 42271, HA 42272, HA 42273, HA 42274; HA 42275; HA 42276; HA 42277; KA 267335, KA 267336; KA 267337; KA 267338; KA 267339; KA 267340; KA 267341), New Providence ( HA 145374, HA 37927; HA 37928; HA 6240; KA 267345; KA 267346; KA 267347; KA 267348; KA 267349; KA 267350; KA 267351; KA 267352; KA 267353; KA 267407).

Alsophis vudii aterrimus Grand Bahama (HA 42117; HA42118; HA 42119; HA 42120; HA 42121; HA 83052; HA 96069; HA 96070; HA 96071; KA 267235; KA 267236), Great Abaco (KA 267237, KA 267238, KA 267239; KA 267243; KA 267244; KA 267245). 40

Alsophis vudii picticeps Bimini ( HA 46060; HA 46061; HA 82890; KA 267246; KA 267247; KA 267248; KA 267249; KA 267250; KA 267251; KA 267252; KA 267253; KA 267254; KA 267255, KA 267256, KA 267257, KA 267258, KA 267259, KA 267260, KA 267261, KA 267262, KA 267263, 267264, 267265, 267266).

Alsophis vudi raineyi Acklins (KA 267267, KA 267268, KA 267269, KA 267270, KA 267271, KA 267272, KA 267273, KA 267274), Crooked ( HA 37937, HA 37938, HA 37939, HA 37940, KA 267277, HA 37930, HA 37931, HA 37932, HA 37933, HA 37934, HA 37935, HA 37936, KA 267275, KA 267276).

Alsophis vudii utowanae Cat (KA 267300, KA 267301, KA 267302), Great Inaugua (KA 267278, KA 267279, KA 267280, KA 267281, KA 267282, KA 267283, KA 267284,KA 267285, KA 267286, KA 267287).

Alsophis cantherigerus adspers Cuba (KA 267050; KA267052; KA267053; KA267054).

Alsophis cantherigerus cayman Grand Cayman (KA 267055; KA 267056; KA 267057; KA 267058; KA 267059; KA 267060; KA 267061; KA 267062; KA 267063; KA 267064; KA 267065; KA 267066; KA 267067; KA 267068; KA 267069; KA 267070; KA 267071; KA 267072; KA 267073; KA 267074; KA 267075; KA 267076; KA 267077; KA 267078; KA 267079; KA 267080; KA 267081).

Appendix B. Sample size (N), means, and standard deviations (SD) for 14 morphological characters by subspecies, island, and sex. (SVL= snout-vent length; TL= tail length; HW= head width; HL= head length; IO= interocular length; IN= inernarial length; NR= naris-rostrum length; EN= eye-naris length; ED= eye diameter; EJ= eye-jaw length; FW=frontal length; PW=parietal width; PL = parietal length). species island sex SVL TL HW HL IO IN NR EN ED EJ FW FL PW PL A.v. Andros M N 14 14 12 12 12 12 12 11 11 11 12 12 12 12 vudii Mean 1.67 1.41 1.02 1.21 0.79 0.56 0.30 0.61 0.57 0.94 0.54 0.80 0.65 0.77 SD 0.07 0.07 0.08 0.08 0.06 0.08 0.13 0.08 0.06 0.06 0.05 0.05 0.05 0.06 F N 8 8 8 8 8 8 8 8 8 8 8 8 8 8 Mean 1.69 1.39 1.06 1.23 0.80 0.59 0.33 0.62 0.54 0.99 0.57 0.82 0.67 0.76 SD 0.13 0.11 0.13 0.11 0.10 0.11 0.11 0.11 0.08 0.13 0.07 0.09 0.09 1.13 Eleuthera M N 10 10 10 10 10 10 10 10 10 10 10 10 10 10 Mean 1.68 1.37 1.03 1.22 0.80 0.58 0.27 0.59 0.55 0.95 0.51 0.79 0.66 0.79 SD 0.07 0.08 0.06 0.05 0.05 0.08 0.11 0.07 0.06 0.06 0.05 0.04 0.05 0.07 F N 9 9 9 9 9 9 9 9 9 9 9 9 9 9 Mean 1.73 1.36 1.09 1.27 0.83 0.63 0.34 0.64 0.59 1.02 0.56 0.80 0.69 0.83 SD 0.06 0.05 0.06 0.05 0.05 0.06 0.11 0.07 0.05 0.07 0.06 0.10 0.05 0.08 Cat M N 23 23 20 20 20 20 20 20 20 20 20 20 20 20 Mean 1.70 1.39 1.06 1.24 0.84 0.62 0.35 0.62 0.59 0.96 0.56 0.83 0.69 0.78 SD 0.04 0.04 0.05 0.03 0.03 0.04 0.08 0.04 0.03 0.04 0.05 0.03 0.03 0.04 F N 17 17 15 15 15 15 15 15 15 15 15 15 15 15 Mean 1.72 1.36 1.08 1.25 0.83 0.62 0.38 0.62 0.61 0.99 0.56 0.83 0.70 0.78 SD 0.05 0.04 0.07 0.04 0.05 0.06 0.05 0.06 0.08 0.06 0.05 0.04 0.04 0.07 42

species island sex SVL TL HW HL IO IN NR EN ED EJ FW FL PW PL A.v. Long M N 6 6 6 6 6 6 6 6 6 6 6 6 6 6 vudii Mean 1.68 1.38 1.04 1.24 0.80 0.59 0.36 0.61 0.55 0.95 0.52 0.80 0.65 0.77 SD 0.05 0.09 0.07 0.05 0.05 0.06 0.06 0.05 0.06 0.06 0.04 0.03 0.04 0.06 F N 7 7 7 7 7 7 7 7 7 7 7 7 7 7 Mean 1.70 1.37 1.06 1.26 0.81 0.59 0.35 0.65 0.56 1.01 0.57 0.83 0.68 0.82 SD 0.07 0.08 0.12 0.08 0.08 0.08 0.07 0.09 0.05 0.10 0.05 0.07 0.06 0.08 Exuma M N 2 2 2 2 2 2 2 2 2 2 2 2 2 2 Mean 1.66 1.42 1.03 1.23 0.80 0.56 0.28 0.60 0.53 0.95 0.51 0.80 0.67 0.78 SD 0.06 0.07 0.01 0.05 0.04 0.06 0.07 0.07 0.07 0.05 0.00 0.05 0.02 0.05 F N 2 2 2 2 2 2 2 2 2 2 2 2 2 2 Mean 1.63 1.33 1.03 1.22 0.78 0.54 0.35 0.58 0.54 0.98 0.51 0.76 0.64 0.78 SD 0.11 0.14 0.17 0.11 0.11 0.13 0.08 0.17 0.09 0.16 0.13 0.09 0.08 0.08 Little M N 3 3 3 3 3 3 3 3 3 3 3 3 3 3 Ragged Mean 1.75 1.35 1.10 1.29 0.85 0.62 0.35 0.66 0.57 1.01 0.58 0.86 0.73 0.85 SD 0.03 0.12 0.05 0.02 0.03 0.01 0.04 0.02 0.03 0.03 0.03 0.03 0.02 0.00 F N 3 3 3 3 3 3 3 3 3 3 3 3 3 3 Mean 1.83 1.48 1.15 1.34 0.89 0.70 0.41 0.73 0.62 1.12 0.59 0.89 0.75 0.91 SD 0.02 0.03 0.02 0.03 0.02 0.03 0.03 0.03 0.04 0.03 0.01 0.02 0.04 0.04 Providence M N 6 6 5 5 5 5 5 5 5 5 5 5 5 5 Mean 1.66 1.38 0.97 1.21 0.76 0.54 0.35 0.57 0.51 0.91 0.50 0.77 0.63 0.77 SD 0.03 0.04 0.06 0.02 0.05 0.04 0.06 0.04 0.01 0.04 0.07 0.01 0.03 0.04 F N 4 4 4 4 4 4 4 4 4 4 4 4 4 4 Mean 1.69 1.34 1.06 1.23 0.81 0.58 0.38 0.60 0.56 0.97 0.57 0.81 0.66 0.80 SD 0.06 0.05 0.07 0.04 0.05 0.05 0.07 0.06 0.02 0.06 0.05 0.02 0.05 0.02 43

species island sex SVL TL HW HL IO IN NR EN ED EJ FW FL PW PL A.v. G Bahama M N 4 4 2 2 2 2 2 2 2 2 2 2 2 2 aterri Mean 1.69 1.43 1.06 1.25 0.81 0.60 0.41 0.57 0.59 1.00 0.55 0.76 0.67 0.81 mus SD 0.03 0.02 0.06 0.05 0.05 0.06 0.01 0.07 0.03 0.03 0.02 0 0.03 0.05 F N 5 5 4 4 4 4 4 4 4 4 4 4 4 4 Mean 1.69 1.38 1.07 1.24 0.83 0.60 0.38 0.57 0.58 1.00 0.54 0.77 0.66 0.82 SD 0.05 0.06 0.05 0.03 0.04 0.04 0.04 0.05 0.02 0.04 0.05 0.03 0.03 0.04 G. Abaco M N 4 4 4 4 4 4 4 4 4 4 4 4 4 4 Mean 1.68 1.40 1.04 1.24 0.80 0.57 0.34 0.57 0.55 0.97 0.49 0.75 0.66 0.84 SD 0.05 0.04 0.05 0.02 0.02 0.05 0.10 0.04 0.05 0.05 0.05 0.05 0.04 0.02 F N 1 1 1 1 1 1 1 1 1 1 1 1 1 1 Mean 1.73 1.42 1.04 1.25 0.82 0.66 0.45 0.58 0.60 0.98 0.57 0.85 0.70 0.80 SD ------A.v. Bimini M N 6 6 5 5 5 5 5 5 5 5 5 5 5 5 pictice Mean 1.74 1.43 1.11 1.28 0.87 0.66 0.34 0.66 0.59 1.04 0.61 0.84 0.67 0.83 ps SD 0.04 0.08 0.06 0.04 0.04 0.04 0.19 0.03 0.03 0.07 0.05 0.04 0.05 0.04 F N 12 12 12 12 12 12 12 12 12 12 12 12 12 12 Mean 1.78 1.38 1.12 1.27 0.86 0.66 0.38 0.66 0.58 1.06 0.63 0.86 0.69 0.83 SD 0.05 0.08 0.07 0.04 0.04 0.04 0.09 0.07 0.03 0.06 0.03 0.03 0.05 0.06 A.v. Acklins M N 2 2 2 2 2 2 2 2 2 2 2 2 2 2 raineyi Mean 1.61 1.32 0.97 1.16 0.74 0.49 0.24 0.53 0.50 0.87 0.52 0.72 0.60 0.74 SD 0.02 0.01 0.02 0.01 0.00 0.03 0.03 0 0.02 0.01 0.02 0.02 0.03 0.02 F N 5 5 4 4 4 4 4 4 4 4 4 4 4 4 Mean 1.75 1.43 1.09 1.27 0.84 0.61 0.32 0.64 0.57 1.04 0.56 0.79 0.70 0.84 SD 0.05 0.03 0.05 0.05 0.04 0.04 0.04 0.08 0.05 0.05 0.03 0.03 0.03 0.07 44

species island sex SVL TL HW HL IO IN NR EN ED EJ FW FL PW PL A.v. Crooked M N 6 6 3 3 3 3 3 3 3 3 3 3 3 3 raineyi Mean 1.71 1.40 1.08 1.30 0.86 0.65 0.40 0.67 0.58 1.05 0.61 0.82 0.70 0.89 SD 0.07 0.07 0.06 0.03 0.06 0.07 0.06 0.07 0.05 0.04 0.03 0.04 0.03 0.02 F N 2 2 2 2 2 2 2 2 2 2 2 2 2 2 Mean 1.65 1.35 0.92 1.20 0.73 0.51 0.27 0.53 0.49 0.92 0.52 0.75 0.60 0.76 SD 0.01 0.03 0.05 0.03 0.07 0.01 0.06 0.01 0.01 0.02 0.03 0.01 0.02 0.02 A.v. G Inauga M N 3 3 3 3 3 3 3 3 3 3 3 3 3 3 utowanae Mean 1.76 1.43 1.06 1.24 0.82 0.60 0.37 0.63 0.56 0.98 0.55 0.78 0.69 0.79 SD 0.02 0.03 0.02 0.03 0.03 0.02 0.03 0.03 0.04 0.04 0.02 0.03 0.04 0.04 F N 5 5 5 5 5 5 5 5 5 5 5 5 5 5 Mean 1.72 1.36 1.04 1.22 0.79 0.58 0.36 0.57 0.53 0.96 0.51 0.75 0.65 0.77 SD 0.12 0.12 0.07 0.09 0.09 0.10 0.05 0.13 0.08 0.10 0.12 0.10 0.07 0.11 A.c. Cuba M N 1 1 1 1 1 1 1 1 1 1 1 1 1 1 adspers Mean 1.74 1.42 1.08 1.29 0.83 0.59 0.36 0.65 0.59 1.00 0.54 0.86 0.70 0.86 SD ------F N 3 3 3 3 3 3 3 3 3 3 3 3 3 3 Mean 1.70 1.35 1.03 1.22 0.78 0.55 0.31 0.58 0.75 1.04 0.49 0.81 0.65 0.75 SD 0.16 0.15 0.20 0.12 0.14 0.15 0.19 0.18 0.21 0.05 0.16 0.08 0.13 0.13 A.c. G M N 15 15 13 13 13 13 13 13 13 13 15 14 14 13 caymanus Cayman Mean 1.79 1.43 1.15 1.31 0.89 0.66 0.43 0.67 0.61 1.05 0.64 0.86 0.74 0.85 SD 0.04 0.07 0.06 0.04 0.06 0.07 0.06 0.06 0.05 0.06 0.09 0.05 0.06 0.05 F N 3 3 3 3 3 3 3 3 3 3 3 3 3 3 45

Appendix C: Sample size (N), means, and standard deviations (SD) for 5 meristic characters by subspecies, island, and sex. (RTEMP= right temporal scales; LTEMP= left temporal scales; DORS= dorsal scales at midbody; VENT= ventral scales; SUBC= subcaudal scale pairs). species island sex RTEMP LTEMP DORS VENT SUBC A.v. Andros M N 16 16 13 13 12 vudii Mean 3.31 3.31 17.00 164.77 118.58 SD 0.60 0.48 0 3.90 9.77 F N 9 9 7 7 6 Mean 3.44 3.89 17.00 169.57 113.83 SD 0.53 1.05 0 2.51 12.54 Eleuthera M N 12 12 11 11 11 Mean 3.25 3.17 17.00 164.18 99.45 SD 0.45 0.39 0 3.06 28.14 F N 11 11 9 8 9 Mean 3.09 3.00 17.22 164.63 100.44 SD 0.30 0 0.67 2.13 8.52 Cat M N 25 25 25 25 25 Mean 3.08 3.04 17.00 166.68 112.57 SD 0.28 0.20 0 1.99 5.75 F N 14 14 15 15 15 Mean 3.00 3.07 17.00 169.20 106.27 SD 0 0.27 0 2.21 5.80 46

species island sex RTEMP LTEMP DORS VENT SUBC A.v. Long M N 5 5 5 5 5 vudii Mean 3.20 3.60 17.00 163.20 119.60 SD 0.45 0.89 0 2.17 9.66 F N 8 8 7 7 7 Mean 3.13 3.25 17.00 129.29 109.43 SD 0.35 0.46 0 67.25 11.03 Exuma M N 2 2 2 2 2 Mean 4.00 5.00 17.00 161.50 115.50 SD 1.41 0 0 0.71 7.78 F N 3 3 2 2 2 Mean 3.00 3.33 17.00 166.00 110.50 SD 0 0.58 0 4.24 4.95 Little Ragged M N 2 2 2 2 2 Mean 3.00 3.00 17.00 163.50 140.00 SD 0 0 0 3.54 41.01 F N 3 3 3 3 3 Mean 3.00 2.67 17.00 169.33 109.67 SD 0 0.58 0 0.58 6.11 N. Providence M N 6 6 6 6 6 Mean 3.50 3.33 17.00 162.00 115.50 SD 0.84 0.82 0 3.52 2.74 F N 5 5 4 4 4 Mean 3.20 3.00 17.00 166.50 103.00 SD 0.45 0 0 2.08 3.74 47

species island sex RTEMP LTEMP DORS VENT SUBC A.v. G Bahama M N 3 3 4 4 4 aterrimus Mean 3.00 3.00 17.00 162.00 114.00 SD 0 0 0 2.16 3.16 F N 5 5 5 5 5 Mean 3.00 3.00 17.00 164.60 104.80 SD 0 0 0 3.51 3.03 G. Abaco M N 4 4 2 4 4 Mean 3.00 3.00 16.00 160.75 108.25 SD 0 0 1.41 2.36 12.18 F N 1 1 1 1 1 Mean 3.00 3.00 17.00 167.00 111.00 SD - - - - - A.v. Bimini M N 5 5 5 5 5 picticeps Mean 3.40 3.00 17.00 164.40 113.80 SD 1.10 0.89 0 1.14 1.79 F N 8 8 8 8 8 Mean 4.00 4.38 18.13 166.88 105.25 SD 1.20 1.30 1.81 1.46 7.01 A.v. Acklins M N 2 2 2 2 2 raineyi Mean 3.00 3.00 17.00 171.50 118.50 SD 0 0 0 3.54 0.71 F N 5 5 4 3 3 Mean 3.40 3.00 17.00 172.33 116.33 SD 0.55 0 0 1.15 3.06 48

species island sex RTEMP LTEMP DORS VENT SUBC A.v. Crooked M N 3 3 3 3 3 raineyi Mean 3.00 3.00 17.00 167.00 112.33 SD 0 0 0 3.00 10.69 F N 2 2 2 2 2 Mean 3.00 3.00 17.00 174.00 121.50 SD 0 0 0 2.83 0.71 A.v. G Inauga M N 3 3 3 3 3 utowanae Mean 3.00 3.00 17.00 182.67 115.00 SD 0 0 0 2.52 15.72 F N 5 5 3 4 4 Mean 3.0 3.0 17.00 184.25 111.50 SD 0 0 0 2.06 8.70 A.c. Cuba M N 1 1 1 1 1 adspers Mean 3 3 3 173.00 116.33 SD - - - - - F N 3 3 3 3 3 Mean 3.0 3.0 17.0 176.67 116.33 SD 0 0 0 2.08 2.89 A.c. G Cayman M N 10 10 11 11 10 caymanus Mean 3.00 3.00 17.00 172.36 114.70 SD 0 0 0 2.69 14.46 F N 3 3 1 2 3 Mean 3.00 3.00 17.00 177.50 108.00 SD 0 0 - 0.71 16.52