Title: Patterns of geographic variation in Florida snakes
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Title: Patterns of geographic variation in Florida snakes
Physical Description: iv, 394 leaves : ill. ; 28 cm.
Language: English
Creator: Christman, Steven P.
Publisher: Steven P. Christman
Publication Date: 1975
Copyright Date: 1975
 Subjects
Subject: Snakes -- Florida   ( lcsh )
Zoology thesis Ph. D
Dissertations, Academic -- Zoology -- UF
Genre: bibliography   ( marcgt )
non-fiction   ( marcgt )
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Thesis: Thesis -- University of Florida.
Bibliography: Bibliography: leaves 389-393.
General Note: Typescript.
General Note: Vita.
Statement of Responsibility: by Steven P. Christman.
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Volume ID: VID00001
Source Institution: University of Florida
Holding Location: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: alephbibnum - 000580565
notis - ADA8670
oclc - 02998120

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PATTERNS OF GEOGRAPHIC VARIATION IN FLORIDA SNAKES


By

STEVEN P. CHRISTMAN












A DISSERTATION PRESENTED TO THE GRADUATE COUNCIL OF
THE UNIVERSITY OF FLORIDA
IN PARTIAL FULFILLMENT OF THE REREQUIREMENTS FOR THE
DEGREE OF DOCTOR OF PHILOSOPHY





UNIVERSITY OF FLORIDA













ACKNOWLEDGMENTS


During the course of my graduate training at the University of

Florida I have received financial support from the Society of Sigma

Xi, and I held a National Defense Education Act Fellowship for one

year. Funds for computer analysis were made available by the North-

east Regional Data Center. I thank all those people who loaned me

specimens or data for analysis in this study. I especially thank my

wife, Sheila, for financial, moral and physical help in all phases of

my academic work.














TABLE OF CONTENTS

.Page

ACKNOWLEDGMENTS. . . . . . . . . ... . . .... ii

ABSTRACT . . . . . . . ... . . . . . . iv

INTRODUCTION . . . . . . . ... ..... .... 1

MATERIALS AND METHODS. . . . . . . . . ... . .. 6

The Problem of Samples and Populations . . . . . . 8
The Mapping Procedure. . . . . . . . ... ... 9
Multivariate Analysis. . . . . . . . ... ... 10
Comparison of Mapped Data. . . . . . . . . .. 10
Geography. . . . . . . . . ... . . . 11

RESULTS. . . . . . . . . ... . . . . .... 14

The Species. . . . . . . . . ... ....... 15
The Patterns . . . . . . . . ... .. .... . 54
The Correlations . . . . . . . . ... ..... 59

DISCUSSION . . . . . . . . ... . . . . . . 331

Pattern of Variation . . . . . . . . ... . 331
Phylogenetic Considerations. . . . . . . . ... 343

SUMMARY. . . . . . . . . ... . . . . .... 371

APPENDIX

A CHARACTERS EXAMINED. . . . . . . . . ... . 373

B ENVIRONMENTAL VARIABLES EXAMINED . . . . . . ... 388

LITERATURE CITED . . . . . . . . ... . . .... 389

BIOGRAPHICAL SKETCH. . . . . . . . . ... ..... 394








iii











Abstract of Dissertation Presented to the Graduate Council
of the University of Florida in Partial Fulfillment of the Requirements
for the Degree of Doctor of Philosophy


PATTERNS OF GEOGRAPHIC VARIATION IN FLORIDA SNAKES

By

Steven P. Christman

December, 1975

Chairman: Archie Carr
Major Department: Zoology

I analyzed geographic variation in fifteen species of Florida

snakes. Machine-produced contour maps were created for each of over

200 morphologic variables and 17 climatic variables. One hundred of

the maps were factor analyzed, and seven major patterns of geographic

variation extracted. These seven patterns were found to account for

over 60% of the information contained in the original contour maps.

Each of the patterns of geographic variation can be explained in terms

of natural selection by past or present environments. Disjunct popu-

lations showing phenetic similarities are the result of an earlier

widespread phenotype followed by differentiation in geographically

intermediate regions. Recourse to land bridge hypotheses and retro-

gressive evolution are not necessary to explain polytopic phenotypes.

Correlations between the patterns of variation and environment are

discussed, but experimental verification of cause and effect relation-

ships are not provided. The geographic localities of primitive character

states and/or primitive species are not the centers of origin for the

groups, but are considered to be areas in which evolution has proceeded

relatively more slowly.

iv













INTRODUCTION


Darwin's theory of natural selection has as its keystone one

important requirement: variation. Implicit in any interpretation of

natural selection as the guiding force behin-d organic evolution is

the assumption that organisms are not all alike. The members of a

population of sexually-reproducing plants or animals are in fact

(except for identical twins) all different, both genetically and

phenotypically. Mutations and recombinations of existing genes insure

the continuance of this variability.' Selection acts on the differences

between organisms by eliminating unfit phenotypes (and hence their

associated genotypes) from the reproductive effort of a population.

However, phenotypes which are unfit in one part of a species' geographic

distribution may be quite fit in another region. Thus geographic

variation in selective pressures, brought about by geographic variation

in environment, predisposes organisms to vary geographically in morpho-

logical, physiological and behavioral traits, even within a single

biological species.

The process of speciation begins when differential selective

pressures act on populations of a species in remote parts of its geo-

graphic range. Natural selection creates different phenotypes in

response to these different selective regimes. When the degree of



IBut see Murray (1972) for a discussion of genetic diversity
maintained by natural selection.










phenotypic divergence includes also reproductive incompatibility, the

populations involved are said to have reached the species level.

Populations of organisms change phenotypically and genetically

through time as they become better adapted to their environment and as

their environment changes. This process is called evolution. Popu-

lations of organisms also change phenotypically and genetically through

space as they adapt to different environments. This phenomenon has been

called geographic variation, but it is really just another form of

evolution. Albert Einstein has shown the equivalence of space and

time in the physical world. Preston (1960, etc.) has pointed out

analogies between space and time in ecology and species diversity. In

this study, it is assumed that character variation through space is a

form of organic evolution just as character variation through time is

unquestionably so.

It is currently impossible to study the environmental factors

responsible for character variation through time. We do not have

accurate data on temperature or rainfall variations throughout the

evolutionary history of any species. We are not able to assess the

relative importance of various selective pressures that have brought

about the species of today. However, we can study evolution through

space. We do have accurate environmental measurements taken at many

geographic points, and should be able to correlate these with character

variation as we see it throughout a species' distribution. Assuming

an analogy between space and time, I believe that patterns of character

variation in space are brought about and maintained in the same ways as

patterns of character variation through time (evolution, in the Darwinian

sense).










Thus the key to an understanding of organic evolution lies in

an understanding of geographic variation and the environmental factors

responsible for its maintainence.

Although the study of geographic variation in living systems is

not a new one, the use of modern multivariate methods to describe and

compare patterns of variation has hardly begun. Most previous studies

have simply described or illustrated the geographic variation of each

of a set of characters pertaining to a single plant or animal species.

A few very recent studies have utilized multivariate techniques to

analyze the degree and type of covariation between characters of a

single species. Still fewer investigators have attempted to demon-

strate correlations between environmental parameters and intraspecific

geographic variation. No previous study, to my knowledge, has attempted

to quantitatively investigate patterns of geographic variation common

to several species, and to compare these patterns with environmental

variation. The present study does just that.

Florida is for the most part a peninsula with a warm temperate

climate grading into that of a subtropical region. It has such diverse

habitats as large swamps and marshes (prairies), forested pine lands,

and scrubby chaparral-like deserts. It thus seems surprising that most

studies concerned with the biogeography of Florida have concentrated on

historical causation and left little credit to the power of natural

selection as a factor in establishing patterns of geographic variation.

Changing sea levels, "Ocala Islands," Suwannee Straits and the like have

all been cited as influencing the patterns of distribution and variation

in Florida plants and animals. No doubt many of the distributional










patterns and much of the variation seen in Florida organisms have been

influenced by these historical phenomena. However, I believe that most

of the variation within species represents adaptation to the present

environment, brought about by natural selection that is still at work.

Recent work by several authors has shown that demes or micro-geographic

populations can and do differentiate as theybecome adapted to their

own specialized environment. Species, in the conventional sense, are

not panmictic. Rather, they are groups of populations, each adapted to

its own particular portion of the total species distribution. There-

fore, any analysis of geographic variation should include tests for

correlation with components of the environment. Only after all possible

correlations with environmental parameters have been eliminated, should

historical phenomena be suggested as causation in biogeography.

Leon Croizat, in a series of works spanning the last thirty years

(especially 1958, 1962) has advocated a method of biogeographical analysis

which begins without a priori assumptions, and lets the data speak for

itself. His method is to plot the distribution of the species of a

given group on a map, and to connect the disjunct ranges with straight

lines. When many groups are treated in this way, it is found that the

lines of connection (tracks) do not form a random network over the map,

but rather, they tend to follow the same routes. These routes, an

aspect of the data, and in no way influenced by preconceived ideas of

past geography or climate, can and must be interpreted as representing

remnants of former wide-spread distributions.

By plotting the geographic patterns of morphologic variation of

a particular species on a map, and then considering many such maps










together, one is, in effect, using a modification of Croizat's pan-

biogeographic analysis on a micro scale. We begin with no assumptions

of past dispersal routes, climate or geography. Instead, the data are

mapped and the patterns emerging interpreted in the most parsimonious

manner.

The method is simple: Computerized contour maps are produced

depicting the geographic variation of each character to be investigated,

one character per map. Next the maps are compared, and a smaller number

of underlying patterns extracted and mapped. These patterns must be

explained. By means of correlation analysis it is possible to compare

the pattern maps with maps of environmental variables such as rainfall

or temperature. In this manner, patterns of organic geographic variation

can be identified and compared with geographic variation in environmental

factors. Patterns of morphologic variation which do not correlate with

the environmental variables may be correlated with untested environmental

variables, or they may have received their present shape by past paleo-

climatic or geographic factors.














MATERIALS AND METHODS


The Data

I analyzed character variation data on 3578 specimens of 15 species

of Florida snakes. The species were chosen on the basis of availability

of specimens or data, and, more importantly, because they are for the

most part, wide-ranging, rather ubiquitous species with representatives

taxonomicallyy distinct or not) in the southwestern United States and

Mexico. It was assumed that species with wide distributions across the

southern United States would be phenetically (and genetically) plastic

throughout their ranges as they adapt to different environments. Geographic

variation in a wide-ranging species is inevitable if we believe in evolu-

tion, and a species' ability to adapt to its environmental surroundings.

Furthermore, it was hoped that some light could be shed on the postulated

"Gulf Coast Corridor" phenomenon of Auffenberg and Milstead (1965) by

studying character variation in species associated with the Gulf Coastal

Plain.

The characters examined were primarily standard taxonomic variables

with a history of application for the species studied. Although color

is probably the single most important aspect of a snake's phenotype at

the infraspecific level, this character was largely ignored, because

of unpredictable color changes that specimens undergo in preservative.

Aspects of pattern, carination and scutellation constitute the bulk of

the characters employed in the present analysis. See Appendix A for a

description of the characters examined.










Once the data were accumulated, they were coded, qualitative

characters were ranked, and everything was punched on computer Holerith

cards. Various combinations of characters were utilized to produce new

characters, such as ventrals plus caudals or percent tail, etc.

In addition to the data on snake morphology, I also recorded and

analyzed summary data on Florida climate from the Climatic Summary of

the United States, U.S. Department of Commerce. These data were also

punched on computer cards. The environmental variables investigated are

listed in Appendix B. Mean data from 196 weather stations in Florida,

southern Georgia and southern Alabama were used. The average period of

record on which means were based was 29 years.

In order to associate data from an individual snake or weather

station with the appropriate geographic locality, it was necessary to

develop a row and column coordinate system. This was done using as a

base map, the 1972 edition of the American Automobile Association road

map for Florida. Each specimen and weather station was assigned a

latitude and longitude value representing its locality on the base

map. These coordinates were punched on the cards along with the data.

Although the use of the AAA road map for a base may seem limiting, it

is not, because the coordinates can easily be changed to any other

system with the appropriate conversion factor. Actual latitude and

longitude values could not be used because these vary in inter-line

distance with the curvature of the earth, and the computational

algorythms employed require that the grid system be uniform.









The Problem of Samples and Populations

In every previous study of geographic variation that I know of,

data on organisms from more or less nearby localities have been pooled

and averaged, with the resultant average values applied to some point

or area representing all the individuals included. This seems to me to

be an arbitrary and unrealistic approach to the problem. Whether the

method employed lumps specimens by state, county, circular or square

grids, or the strange "splotch" system of Rossman (1963) and his students

(Blaney, 197Ta; Williams, 1970; etc.), the implication is that the values

associated with the geographic units represent values for populations.

There is no reason to believe that populations assume regular shapes

any more than shapes determined by political boundaries. Nor is there

any valid reason for lumping specimens with "similar" character states

from "adjacent" localities. What are "similar" and "adjacent?"

The method used in the present study is, I believe, less arbitrary,

and does not assume a knowledge of either population structure or geog-

raphy. The character state for each specimen is plotted on a map at the

point where the specimen was collected. If several specimens are avail-

able from the same point, they are averaged; otherwise, each specimen is

plotted independently. The next step involves calculating hypothetical

values for intermediate localities based only on the data available.

Character values are weighted inversely according to the square of their

distance from the point being considered. In this way values for all

points on the map (or any fraction thereof) are calculated based on the

points for which there are actual values. Contour lines can be con-









structued, and the areas of character change readily identified. Instead

of a priori assumptions of geographic structure which are implicit in any

scheme involving the means of putative populations, this method allows

the patterns of geographic variation to emerge from considerations of

individual specimens.

The Mapping Procedure

This method of character mapping still suffers from the one draw-

back common to all methods: the map is only as good as the data.

Obviously, the more points on the map with actual data values, the less

interpolation will be necessary to identify the areas of character change.

Ideally, we would like to have our specimens from regularly-spaced

localities gridded over the entire map surface. This is simply not

possible in the majority of cases, and probably never possible when

studying snakes.

Throughout the following discussion, it is necessary to keep in

mind that the mapping procedure employed does nothing more than map the

data as they appear, and interpolate between data points, just as a

cartographer would do, mentally, in constructing a contour map by hand.

There is nothing mysterious or even very sophisticated in the method. It

is faster than mapping manually, and it removes the element of bias from

contour line placement.

The actual computer program used in the production of character

variation maps was the SYMAP program developed by the Harvard University

Laboratory for Computer Graphics. This program has been used previously

in geographic variation studies by Jackson (1970) and Johnston and

Selander (1971), and is described in some detail in Peucker (1972).









Multivariate Analysis

The SPSS factor analysis procedure (Nie et at., 1970) was employed

to extract factor scores from the data set for each species studied. If

morphological characteristics of an organism co-vary, then there is some

underlying component or "factor" that will explain the variation in the

suite of characters that are varying together. This is the assumption

behind factor analysis. First a matrix of product-moment correlation

coefficients between the variables was calculated. R-type factor

analysis was employed to extract a smaller number of summarizing axes

that explain the covariation in the characters. These axes represent

a "summary" of the variation in a larger number of variables. Based

on these factor axes, factor scores were assigned to each specimen, and

these values mapped like univariate characters. The finished product

is a map of the geographic variation of a factor, which is, by definition,

a map of the underlying trends of geographic variation in a suite of

characters, where such underlying trends exist. A more detailed discus-

sion of Factor Analysis may be found in Harmon (1962).


Comparison of Mapped Data

The problem of comparing mapped data is a complex one. Prior to

this study there were no available methods for analyzing maps or perform-

ing correlation analysis between maps. If the variables to be analyzed

were located geographically at the same point, simple product-moment

correlation analysis could be performed and any correlative tendencies

readily discovered. However, when the maps to be compared have different

data points, a preliminary step to standardize the reference points is









necessary. That is, given two maps of Florida, one with X data points

(set A) and the other with Y data points (located at different points,

set B), it is necessary to interpolate each data set to a standard grid

system, or to interpolate one data set so that its new grid system corre-

sponds with the other. If the data are treated in this manner, it is

possible to compare climatic variables from U.S. weather stations, with

morphological variables of snakes from wherever they were collected

(usually not weather stations).

The SYMAP mapping routine, discussed above, calculates estimated

data values for a finite number of points on a map based on the values

associated with actual data points. It is possible to output the values

so calculated for one data set, and compare these with values output from

another data set run in the same way at another time. In this way,

multiple sets of geographic data can be standardized to a grid system

by non-arbitrary, reproducible methods (SYMAP) and the resulting grids can

be treated as matrices in correlation, cluster, or factor analysis.

A computer program to handle the SYMAP-produced data point values

and store these on magnetic tape for later analysis was written for this

study by William Ingram.

Geography

Regional and place names used in this study are located on Fig. 1.

The major rivers of Florida are shown on Fig. 2. Figs. 1 and 2 should

enable the reader not familiar with Florida to follow easily the results

and discussions presented below.

















PANHANDLE OKEFENOKEE SWAMP
OKEFENOKEE SWAMP


GULF
/HAMMOCK




LAKE
WALES
RIDGE






VERGLADES


UPPER KEYS
UPPER KEYS


LOWER KEYS


Figure 1. Regional and place names referred to in the text.


TAMPA
BAY







13









w




ULI
m

oo


0w
w
u








a
o y




0 <

"U-
Sw


0 -









C-
E













r-


4fo-
V," O A













RESULTS


Pearson Product-Moment correlation coefficients were calculated

between every character and sex and snout-vent length for each species.

Unless otherwise noted, all characters mapped showed no correlation with

sex or body size. Note that the mapping procedure employed does nothing

more than assign a given value to the appropriate locality, then inter-

polate between the localities to predict the location of a change in

character state. Each specimen is weighted equally, so geographically

isolated specimens may contribute more heavily in the analysis than

individual specimens from better-collected regions. That is, if only

a single specimen is available from region A, then that region will be

shaded as though the population had the characteristics of that specimen.

If 20 specimens were available from the same region, the shading would

reflect the average of those 20 specimens. When interpreting the maps

in this section, it is important to bear this in mind, and to refer to

the specimen locality maps presented for each species.

Results are presented first by species, and compared with previous

studies. Patterns of geographic variation are discussed in the second

section, and finally, a third section deals with correlations between

observed patterns and environmental factors. A description of each of

the characters examined appears in Appendix A. Actual raw values may

be obtained from the author.










The Species

Storeria dekayi (Holbrook)

I examined 151 specimens of Storeria dekayi from Florida and

southern Georgia (Map 1) for possible geographic variation in each of

21 characters (Appendix A). The numbers of supralabials and infra-

labials are essentially unvarying over the study area. More than 93%

of the specimens examined had 14 supralabial combining both sides, and

87.4% had 14 infralabials. The number of postocular scales was usually

four (88.3%). None of the characters examined was found to be size-

correlated. The following characters showed apparent geographic

variation.

Number of ventrals. The number of ventral scales in Florida

Storeria dekayi was only slightly correlated with sex, with the males

usually having lower counts (r = 0.3559). Nevertheless, the sexes were

mapped separately as shown in Maps 2 and 3. In general, the number of

ventrals increases southward on the peninsula and drops again on the

Lower Keys. The highest ventral counts are observed on snakes from the

Everglades region, while the lowest values are found on the Lower Keys

and in the Panhandle. A reasonable degree of concurrent variation between

the sexes suggests that they are responding similarly in ventral count

expression.

Number of subcaudals. Males tend to have more subcaudals than

females (r = 0.5167). Geographic variation in the number of subcaudals

in Florida S. dekayi is shown in Maps 4 and 5. Variation is similar to

that described for ventrals, above. Snakes from the Panhandle and from










the Lower Keys have the lowest subcaudal counts. Otherwise, the

variation is clinal, increasing southward on the Florida peninsula.

Brown snakes from the Apalachicola Valley may be more similar to snakes

from Central Florida as regards this character. Again, concordance in

the patterns of variation observed in the sexes is very good.

Number of ventrals plus caudals. Although both the number of

ventrals and the number of subcaudals are correlated with sex (see above)

their sum is not (r = 0.1522). Therefore, the sexes can be lumped to

increase sample size, producing Map 6. Geographic variation in this

character consists of increasing counts southward on the peninsula, and

a major drop on the Lower Keys. Snakes from west of the Suwannee River

in the Panhandle also have low values for this character. (Note that the

area west of the Yellow River is represented by only a single specimen,

and is therefore an inadequate sampling.)

Percent tail. Males tend to have proportionately longer tails

(r = 0.7214), and so the sexes have been mapped separately in Maps 7 and

8. Brown snakes from the southern mainland have the longest tails

proportionate to body length. Snakes from the Lower Keys have somewhat

shorter tails, more like specimens from northern Florida.

Dorsal scale rows. Dorsal scales were counted at the standard

three places along the body, but all three varied the same way, so only

midbody scale rows are mapped (Map 9). Brown snakes from the Panhandle

east to the vicinity of the Suwannee River have 17 scale rows around the

body, while those from the remainder of the state have 15.

Preocular scales. Generally, Storeria dekayi has a single preocular

scale on each side of the head. However, individuals from the Lower Keys









typically have two preoculars on each side. In addition, a high pro-

portion of specimens from near Jacksonville and Gainesville in northern

Florida have two preoculars on each side. See Map 10.

Ventral dark pigmentation. Geographic variation in the qualitative

assessment of the amount of dark pigment ventrally in Florida S. dekayi is

presented in Map 11. Generally speaking, brown snakes from the south-west

coast of the peninsula have the darkest bellies, while those from the Lower

Keys have the lightest.

Temporal pigmentation. Dark pigment on the temporal scale in S.

dekayi may be in a tear-shaped blotch with one end wider and continuing

onto adjacent scales (see Appendix A). The wider end may be directed

posteriorly as in most snakes from the Panhandle, or it may be directed

to the front as in specimens from the Florida peninsula. Brown snakes

from the Lower Keys often have the temporal pigment so reduced as to have

no obvious orientation, but when present, the wider end is directed to

the front. See Map 12.

Subocular pigmentation. The number of supralabial scales contained

within the subocular dark blotch in Florida S. dekayi varies geographically

as shown in Map 13. Generally, snakes from the peninsula tend to have

larger subocular spots than specimens from the Panhandle. Many individuals

from the Everglades region have very small or absent subocular spots.

Subocular spots on specimens from the Lower Keys are diffuse and faint,

but cover three to five supralabials.

Factor 1. The first factor accounts for 24% of the variation in 18

characters. It accounts for most of the variation in the three dorsal

scale row counts, the sum of ventrals plus caudals, temporal pigmentation,










ventral pigmentation, and supralabial pigmentation. The first factor

discriminates between two phenotypes of Storeria in Florida: snakes

with 17 dorsal scale rows, fewer than 187 ventrals plus caudals, a

temporal blotch with its wider end directed posteriorly, reduced ventral

pigment, and fewer supralabials with black pigment occur in the Pan-

handle, while snakes of a contrasting phenotype occur on the peninsula.

See Map 14.

Thamnophis sirtalis (Linnaeus)

Data on 192 specimens of Thamnophis sirtalis from Florida (Map 15)

were analyzed for possible geographic variation in each of 13 characters

(Appendix A). Dorsal scale rows varied little throughout the study area,

with most specimens having 19-19-17 scale rows (94.7%, 95.7%, and 96.8%

respectively). Ninety-one percent of the T. sirtalis examined had 14

supralabials and 92.4% had 20 infralabials. None of the characters

examined was size- or sex-correlated. The following characters appear

to show trends of geographic variation within Florida.

Numbers of ventrals. Geographic variation in the number of ventral

scales in T. sirtalis is shown in Maps 16 and 17. Although differentiation

within Florida for this character is minimal, some trends are apparent. In

general, garter snakes from Lake Okeechobee southward have the highest

ventral counts. Snakes from the Panhandle tend to have low counts. It

is not possible, however, to discern a well-developed dine within the

state of Florida.

Number of subcaudals. Trends in the geography of subcaudal count

variation in Florida garter snakes are not clear. Maps 18 and 19 show









the general lack of concordance between the sexes for this character.

Patterns like these may imply that the sexes are responding differently

in subcaudal count expression, or they may be the result of sampling

bias due to inadequate sample sizes (51 males, 62 females). Alternatively,

the number of subcaudal scales in Florida T. sirtaZis may not correspond

with anything that varies geographically.

Number of ventrals plus caudals. The summation of the proceeding

two characters varies geographically as shown in Map 20. Garter snakes

tend to have the highest counts in the northern peninsula and extreme

southern peninsula, with lower counts found in the intervening region,

and in the Panhandle.

Percent tail. Tail length divided by total length varies as shown

in Maps 21 and 22. In general, specimens from Apalachicola Valley, the

northern peninsula, and the southern peninsula have proportionately

longer tails than snakes from elsewhere. Although the pattern appears

complex, the concordance between the sexes is quite good, supporting the

reality of the trends, based, as they are, on different sets of specimens.

Dorsal spotting. That some individuals of Thamnophis sirtalis are

marked with black spots dorsally is well known. Linnaeus (1766) described

the phase as Coluber ordinatus; Cope (1900) considered it a subspecies of

T. sirtalis, and more recent authors have considered it little more than

an occasional pattern variant without geographic correlation (Rossman,

1965). Maps 23, 24, and 25 show the geographic variation in this character

for Florida specimens. Garter snakes from the western Panhandle usually

have a well-developed pattern of dorsal checks, sometimes to the complete

exclusion of longitudinal stripes. Additionally, the west coast of the










peninsula and parts of the Central Highlands support populations of T.

sirtalis with dorsal checking. Specimens from the southern Everglades

are almost invariably heavily spotted.

Parietal spots. Rossman (1963) considered the nature of the paired

parietal light spots important to the taxonomy of the genus Tharmophis.

The pattern of geographic variation in thischaracter is remarkably

similar to that seen in the previous character, dorsal spotting. Maps

26, 27, and 28 show the geographic variation as interpreted in the present

study. Again, the Panhandle, the southwest coast of the peninsula and the

southern Everglades stand out as areas with higher states for this

character. Concordance between the sexes is good.

Factor 1. The first factor extracted from the correlation matrix

of eleven characters accounts for 18.5% of the total variation, and much

of the variation in dorsal spotting and parietal spots. Map 29 shows

how factor 1 varies in Florida. The western half of the Panhandle, the

southwestern coast of the peninsula, and much of the Central Highlands

and southern Everglades support populations of garter snakes characterized

by well-developed dorsal and parietal spots.


Thamnophis sauritus (Linnaeus)

I analyzed data on 279 specimens of Thamnophis sauritus from Florida

and southern Georgia (Map 30) for possible geographic variation in each of

13 characters (Appendix A). Another 12 specimens from the Lower Florida

Keys were examined and included in the discussion, but were not available

at the time of mapping. The number of infralabials was essentially un-

varying throughout the study area (92.6% had ten on each side). None









of the characters investigated was correlated with snout-vent length.

Those characters which showed trends of geographic variation follow.

Number of ventrals. Males and females do not differ significantly

in ventral counts (r = 0.2910). Maps 31 and 32 show the apparent clinal

increase in ventral counts for both sexes southward on the Florida

peninsula. Higher ventral counts tend to extend farther northward along

the coasts, and specimens from the Gulf Hammock region on the east coast

have ventral counts comparable to snakes from the most southerly localities.

Data from Paulson (1968) and from the present study indicate that T.

sauritus from the Lower Keys have ventral counts like those seen in

specimens from the southern mainland. Seven males from the Lower Keys

averaged 163.4 ventrals and five females averaged 160.2.

Number of subcaudals. Males usually have more subcaudal scales

than females (r = 0.5801), and the sexes have been mapped separately in

Maps 33 and 34. Ribbon snakes from the Panhandle west of the Chocta-

whatchee River tend to have more subcaudals than specimens from the

remainder of the Panhandle and northern peninsula. Snakes from the

peninsula usually have higher counts than specimens from the Panhandle,

and there seems to be a weakly differentiated dine of increasing counts

southward on the peninsula. Specimens examined from the Lower Florida

Keys have higher subcaudal counts than ribbon snakes from anywhere else

in Florida. Seven males averaged 137.9 subcaudals and three females

averaged 126.0.

Number of ventrals plus caudals. The summation of the two previous

counts was found to correlate with sex (r = 0.5201), with males having

more total ventral and subcaudal scutes. Maps 35 and 36 show how this










character varies in Florida. The variation tends to be clinal, with values

increasing southward. Higher values extend farther north along the coasts

of the peninsula. The highest values observed in Florida ribbon snakes

are associated with specimens from the Lower Keys. Seven males from the

Lower Keys had an average ventral plus caudal value of 301.3, and three

females averaged 286.2 ventrals plus caudals.

Percent tail. Ribbon snakes with the longest tails relative to

snout-vent length tend to occur in the central part of the peninsula,

with specimens having lower values occurring both north and south. In

addition, the few specimens available from the extreme western Panhandle

and the Lower Keys suggest that snakes from these areas also have longer

relative tail lengths.

Supralabials. Ribbon snakes from the Panhandle generally have

seven upper labials on each side, while those from the peninsula have

eight. Although not mapped, the ribbon snakes from the Lower Keys

occasionally have seven supralabials as well. Map 37 shows the geo-

graphic variation in supralabial number for both sexes of Thcanophis

sauritus from Florida.

Dorsal stripe edge. Geographic variation in the width and

development of the black border of the dorsal stripe is figured in

Maps 38, 39, and 40. Although the pattern is complex, congruence between

the sexes is good. Thamnophis sauritus from the Panhandle west of the

Apalachicola River and from parts of the central peninsula tend to have

well-developed dorsal stripe edges. Snakes examined from the Lower Keys

have extremely well-developed black dorsal stripe borders. Many specimens

from the northern half of the Florida peninsula lack a stripe border










altogether, and some lack even the mid-dorsal yellow stripe (Rossman,

1963).

Parietal spot. Although Rossman (1963) stated that the nature of

the paired parietal light spots in T. sauritus does not vary geograph-

ically, my analysis of his data indicates that it does. Maps 41, 42, and

43 show this variation. Most Florida T. sauritus lack a distinct parietal

spot. However, specimens from the extreme northern Florida peninsula, at

the edge of the Okefenokee Swamp, the area east of Tampa Bay, and the

southern tip of the peninsula have distinct parietal spots. The concord-

ance between the sexes in the geographic pattern of variation observed

in this character support the reality of the pattern. The few specimens

available from the Lower Keys have weakly developed parietal spots.

Ground color. Most ribbon snakes from Florida have a tan or light

brown ground color. However specimens from the Gulf Hammock region usually

have a very dark brown or black ground color. Some specimens from the

Everglades and southern mainland also have a darker ground color, but

specimens seen from the Lower Keys are light brown or tan. See Map 44.

Factor 1. The first factor extraced from the correlation matrix

of ten characters accounts for 22.3% of the total variation, and most of

the variation in parietal spot distinctiveness and parietal spot size.

Map 45 shows how the first factor varies geographically. Higher states

are associated with snakes from the northern peninsula, the area east of

Tampa Bay, and the southern tip of the peninsula.

Coluber constrictor Linnaeus

I examined 440 specimens of Coluber constrictor from Florida

(Map 46) for possible geographic variation in each of 18 characters










(Appendix A). The numbers of supralabials and infralabials were

practically nonvariant with seven and eight respectively on each side.

Aspects of the color and pattern were scored only on adult snakes (over

70 cm). With ontogenetic change in color and pattern thus taken out of

the picture, none of the characters investigated was found to correlate

with snout-vent length. Those variables that showed trends of geographic

variation within the study area are discussed below.

Number of ventrals. There is no significant difference between

males and females in ventral counts (r = 0.2253), and the sexes have been

lumped to produce Map 49. Maps 47 and 48 show the good degree of con-

cordance between the patterns of variation in the two sexes. There is

a well-developed clinal increase in number of ventrals as one proceeds

southward down the peninsula. Specimens from the Lower Keys do not

follow this trend, however, having much lower ventral counts than

specimens from the southern tip of the mainland. It is also noteworthy

that occasional specimens from the Apalachicola River Valley have higher

than expected ventral counts, being more like specimens from farther

south on the peninsula in this regard.

Number of subcaudals. Males tend to have more subcaudal scales

than females (r = 0.3898), although the correlation is not a strong one.

Maps 50 and 51 show the geographic variation in subcaudal counts for

Florida Coluber constrictor. Specimens from the Panhandle usually have

lower counts than those from the peninsula. On the peninsula, there

may be a very weakly defined clinal increase in subcaudal numbers for

each sex, but any tendency in that direction is well masked.

Number of ventrals plus caudals. Map 52 shows the dine on the

Florida peninsula of increasing ventral scute counts southward, except










for a dip on the Lower Keys. The sexes could be lumped in this map

because ventrals plus caudals is independent of sex (r = 0.1618).

Supralabial loreal contact. Auffenberg (1955) first noted

the variability of this character. In some specimens of Coluber,

especially in the south-eastern United States, the first supralabial

is in contact with the loreal. Although Auffenberg did not believe

that this character varied with any degree of geographic regularity,

my analysis has shown that it does. Map 53 shows that specimens from

extreme northern Florida, the area east of Tampa Bay and extreme southern

Florida, including the Middle Keys tend to have the first supralabial

in contact with the loreal more frequently than specimens from the

remainder of the state. This pattern occurs repeatedly in Florida snakes

and must be considered indicative of some geographic factor based on

present or past environments.

Ventral white. Geographic variation in the amount of white on

the ventral surface in Florida C. constrictor is shown in Maps 54, 55,

and 56. Snakes under 70 cm have been excluded from this analysis.

Black snakes from south Florida and the Everglades region have almost

totally white undersides. Snakes with the darkest bellies (i.e. the

least white) are found on the Lower Keys and extreme northern Florida.

Lighter colored ventrums seem to be associated with the coastal and

treeless areas of the state. The black snakes on the Upper Keys are

intermediate between Lower Keys and south Florida mainland specimens.

The correspondence between the sexes is excellent.

Gular brown pigmentation. Map 57 displays the geographic variation

in the presence or absence of brown pigment on the gular scales in Florida









Coluber. Most black snakes from the Lower Apalachicola River Valley have

brown pigment on the gulars. Snakes from the remainder of the state

seldom have such pigment. When the sexes were mapped separately, the

patterns were virtually identical.

Supralabial brown pigmentation. See Maps 58, 59, and 60 for the

geographic variation in this character. Black snakes from the lower

Apalachicola Valley have the most brown pigment on the supralabial scales.

Snakes from the southern part of Florida peninsula and the Everglades tend

to have some supralabial brown, but not as much. Black snakes from the

extreme southern tip of the peninsula and from the Lower Keys generally

do not have any brown pigment on the upper labials.

Gular black pigmentation. The presence or absence of black on the

gular scales in Florida Coluber varies geographically as shown in Map 61.

The extreme northern base of the peninsula just south of the Okefenokee

Swamp, the area east of Tampa Bay, and the Lower Keys support populations

of C. constrictor with black on the gular scales.

Supralabial black pigmentation. The amount of black pigmentation

on the supralabial scales varies geographically much like the previous

character (see Maps 62, 63, and 64). The congruence between the sexes

is remarkable, and can be considered as very strong evidence for the

reality of the pattern. Black snakes from extreme northern Florida, the

area east of Tampa Bay and the Lower Florida Keys have more black pigment

on the supralabial scales than specimens from anywhere else in Florida.

Factor 1. The first factor accounts for 17.4% of the total vari-

ation in 16 characters. This factor accounts for most of the variation

in gular black pigmentation and supralabial black pigmentation as well










as much of the variation in ventral white pigmentation. Its geography

(Map 65) shows regions with similar phenetic responses in northern

Florida, the area east of Tampa Bay and the Lower Florida Keys.

Factor 3. This factor accounts for 13.2% of the total variation

in 16 characters, and most of the variation in gular and supralabial

brown pigmentation as well as part of the variation in the number of

ventrals plus caudals. Snakes with high factor 3 scores (higher values

for brown pigmentation characters and lower ventral plus caudal counts)

tend to occur in the Apalachicola River Valley, especially the lower

valley, and the Everglades region of south Florida. See Map 66.


Masticophis flagellwum (Shaw)

I analyzed data on 85 specimens of Masticophis flagewlum from

Florida, southern Alabama and southern Georgia (Map 67) for possible

geographic variation in each of nine characters (Appendix A). Over 96%

of the specimens examined had 16 supralabials. None of the characters

was size-correlated. Those which appear to vary geographically follow.

Number of ventrals. Male coachwhips usually have more ventrals

than females (r = 0.4010). Maps 68 and 69 show that in general, the

highest ventral counts are found in snakes from the peninsula, and

especially the western half of the peninsula. Correspondence between

the sexes is weak.

Number of subcaudals. Males and females are not significantly

different in subcaudal counts (r = 0.2425), and have been lumped to

produce Map 70. It appears that specimens from the Panhandle and western

parts of the peninsula usually have more subcaudal scales than snakes from

the eastern peninsula.










Ventrals plus caudals. The summation of the proceeding two charac-

ters is not correlated with sex (r = 0.3219) and varies geographically as

in Map 71. Again, the Panhandle and western part of the peninsula are

characterized by coachwhips with higher ventral counts.

Percent tail. Tail length divided by total length is not corre-

lated with sex (r = 0.2422), and the sexes have been lumped to produce

Map 72. Longer tails seem to be associated with specimens from the

Panhandle and western parts of the peninsula.

Color phase. Most Masticophis from the Panhandle of Florida are

of the light color phase, and most from the peninsula are dark. However,

as shown in Maps 73, 74, and 75 there is some individual variation in this

character. Furthermore, there appears to be two areas in peninsular

Florida where snakes of the light phase are more common. This same

pattern appears in both sexes, lending credence to its reality. Un-

fortunately, the sample sizes are very small.

Factor 1. The first factor accounts for 43.0% of the total varia-

tion in five characters, and most of the variation in ventrals plus caudals,

and part of the variation in number of infralabials. Its geography,

depicted in Map 76, shows a pattern of high factor 1 scores in the Pan-

handle and northern peninsula separated from another area of high values

in southern Florida by an intervening region where the coachwhips tend

to have fewer ventral scutes and infralabial scales.


Opheodrys aestivus (Linnaeus)

I examined 176 specimens of Opheodrys aestivus from Florida (Map

77) for geographic variation in each of 16 characters (Appendix A).








Supralabial and infralabial counts remained essentially constant through-

out the study area with 87.4% having 14 supralabials and 75.6% having 16

infralabials. Dorsal scale rows were found to be 17-17-15 for over 95%

of the specimens examined. Three measurements of the frontal scale were

found to correlate with snout-vent length even after standardization by

dividing by snout-vent length. The characters which appear to show

geographic variation are discussed below.

Number of ventrals. Female green snakes typically have more ventral

scales than males (r = 0.3991). There is no obvious well-developed dine

in ventral counts for Florida Opheodrys. However, specimens from the

southern parts of the state, and especially the south-west usually do

have the highest counts.

Number of subcaudals. Green snake males tend to have higher sub-

caudal counts than females (r = 0.5513). Specimens from the western

Panhandle east to the Apalachicola River tend to have the most subcaudal

scales, while specimens from the Everglades and southern peninsula have

the least.

Ventrals plus caudals. Although both ventrals and caudals were

found to be correlated with sex, their summation was not (r = 0.2807).

Map 78 shows the geographic variation in this character for the combined

sexes. Highest values are associated with snakes from the western Pan-

handle and parts of South Florida. Snakes from the Everglades region

have the lowest ventral scute values. The variation is complex, and it

is not possible to discern a simple north-south dine in this character.

Percent tail. Relative tail length in Florida green snakes varies

with sex. Males usually have proportionately longer tails (r = 0.5211).










Concordance between the sexes is poor. In general, however, both sexes

tend to have slightly longer tails in the Panhandle, and shorter tails

south of Lake Okeechobee. In addition, the males show a pattern of

longer tails on the Lower Keys, while the females do not.

Keeling of the second dorsal scale row. Maps 79, 80, and 81 show

the geographic variation in the development of the keel on the scales of

the second dorsal row at midbody. The maps for the two sexes indicate that

the variation is very similar. North of central Florida and in the Pan-

handle green snakes tend to have reduced or no keeling on these scales.

In central Florida, south throughout the peninsula, states for this charac-

ter tend to be higher, with the highest states frequently associated with

snakes from coastal regions. On the Lower Keys, the males have keeled

scales on the second row, but the females apparently do not.

Supralabial pigmentation. Maps 82, 83, and 84 show the geographic

variation in the amount of dark pigmentation on the upper labial scales in

Florida Opheodrys aestivus. The strong degree of concordance between the

sexes may be taken as evidence for the reality of the pattern, since the

two maps are based on separate sets of specimens. In general, snakes with

more dark pigment on the supralabials occur in the Panhandle, the northern

parts of the peninsula, and southward along the west coast. Green snakes

from the Keys have very light colored upper labials.

Factor 3. This multivariate character varies geographically as shown

in Map 85. It accounts for 12.6% of the total variation in ten characters,

and most of the variation in keels of the second dorsal scale row and supra-

labial pigmentation. Green snakes from the southern half of the peninsula

have less supralabial pigment, and better developed keels on their second









scale fow. Snakes from extreme northern Florida may have higher Factor 3

scores, like specimens from the south.


Elaphe guttata (Linnaeus)

I examined 455 specimens of Elaphe guttata from Florida, southern

Georgia, and southern Alabama (Map 86) for possible geographic variation

in each of 16 characters (Appendix A). Some of the characters varied

little throughout the study area. Dorsal scale rows counted at three

points along the body were almost always 25-27-19. Measurements of the

frontal scale were divided by snout-vent length, and found to correlate

with snout-vent length. These characters were excluded from the analysis

that follows.

Number of ventrals. Females usually have more ventral scales than

males (r = 0.5933). In both sexes, ventral counts increase southward on

the Florida peninsula, with the highest values associated with snakes from

the Lower Keys. Coastal areas also seem to support E. guttata with higher

ventral counts. Maps 87 and 88 depict the geographic variation in ventral

numbers for E. guttata from Florida.

Number of subcaudals. Males tend to have more subcaudal scales than

females (r = 0.5015). The number of subcaudals in Florida corn snakes

appears to increase southward on the peninsula, but the trend is not as

clear-cut as in the proceeding character. See Maps 89 and 90.

Ventrals plus caudals. The summation of ventrals and caudals is

not correlated with sex (r = 0.1118), and so the sexes could be lumped

to increase sample size (Map 91).

The highest counts occur on snakes from the Florida Keys and

adjacent mainland. Higher counts are frequently associated with coastal









areas as well. The lowest ventral plus caudal counts occur on snakes

from the northern peninsula and Panhandle.

Number of body blotches. EZaphe guttata from the Lower Keys have

the highest dorsal blotch counts. Specimens from the Panhandle and

northern peninsula have the lowest. Higher counts reach farther north-

ward on the peninsula along both coasts. Maps 92 and 93 show the geo-

graphic variation in number of body blotches in Florida E. guttata.

The rather high degree of individual variation in this character

partially obscures the clinal nature of its geography.

Number of tail blotches. Corn snakes from the Lower Keys and

south Florida mainland have the highest tail blotch counts. Maps 94

and 95 show the geography of this character. The lowest tail blotch

counts are seen in snakes from the Panhandle, and the increase south-

ward is probably clinal, although complicated by individual variation

from snake to snake.

Blotch border. The red blotches on the dorsum of Florida corn

snakes are usually surrounded by a narrow black border. The width of

this border varies geographically as shown in Map 96. Snakes from the

extreme south Florida mainland and parts of the western Panhandle have

wider blotch borders.

Lateral blotch shape. Corn snakes from the Panhandle of Florida

east to the Aucilla River frequently have the border of the lateral

blotch open ventrally, suggesting an inverted U rather than a complete

circle. The character occurs sporadically throughout Florida, but is

almost universal among Panhandle specimens. See Map 97.

Ventral pigmentation. Corn snakes from the Lower Florida Keys

have the least dark pigment ventrally. Snakes in coastal areas and










other off shore islands have reduced pigment, while the majority of

specimens from the remainder of the peninsula and Panhandle tend to

have much black pitment on their ventral surfaces. Maps 98, 99, and

100 show the geographic variation of this character in Florida E.

guttata.

Ventral check shape. The ventral dark pigmentation is generally

confined to discrete rectangles. Snakes from the Lower Florida Keys and

coastal regions (especially the south-west coast) have small, often

square pigment spots ventrally. Specimens examined from more interior

regions, especially in the northern parts of the state, have their

ventral pigment in elongated rectangles. Many specimens from the

Panhandle and extreme northern Florida have wide rectangular pigment

spots covering entire ventral scutes.

Factor 1. The first factor accounts for 19% of the total varia-

tion in 12 characters. Factor 1 accounts for most of the variation in

ventrals plus caudals, number of body blotches and number of tail

blotches. Map 101 shows how this multivariate character varies geo-

graphically in Florida. Snakes from the Florida Keys and southern parts

of the peninsula tend to have high factor 1 scores, while the lowest

values are associated with Panhandle specimens.

Factor 2. The second factor accounts for 15.0% of the total

variation, and most of the variation in the amount of ventral dark

pigmentation, and the shape of the ventral pigment blotches. Low

values (that is, lighter bellies with smaller blotches) are associated

with corn snakes from coastal areas, and the lowest values of all are

seen in specimens from the Lower Keys. See Map 102.










Elaphe obsoleta (Say)

I analyzed data on 370 specimens of Elaphe obsoleta from Florida

(Map 103) for potential geographic variation in each of six characters

(Appendix A). None of the characters investigated was correlated with

size. The sex of the specimens was not determined.

Number of dorsal blotches. The number of body blotches in E.

obsoleta increases clinally on the Florida peninsula to the south.

Map 104 shows the variation in this count.

Ground color. The dorsal ground color of Florida E. obsoleta

varies geographically as shown in Map 105. This character attempts

to describe the amount of melanin or dark pigmentation on the dorsum

of these snakes. In general, specimens from coastal areas have the

lightest ground colors. Most chicken snakes from the interior of the

peninsula, the Panhandle, and the Upper Keys have darker dorsums. (The

species does not occur on the Lower Keys.)

Stripe development. Elaphe obsoleta from the Panhandle east to

the vicinity of the Suwannee River generally lack dorsal stripes. With-

in the peninsula, specimens from more northerly regions have the most

well-defined stripes, while most examples from southern Florida have

moderately-developed dorsal stripes. See Map 106.

Blotch development. Chicken snakes from the Florida Panhandle

east to the vicinity of the Suwannee River, and southward along the

west coast to the vicinity of the Withlacoochee River have dorsal

blotches. Those specimens south of the Suwannee have dorsal stripes

as well, and are recognized as the subspecies E. obsoleta williaasi.

In addition, E. obsoleta from the Upper Keys and extreme southern










Florida mainland have fairly well-developed dorsal blotches, and have

been called E. o. deckerti. See Map 107.

Ventral pigmentation. Map 108 shows the geographic variation in

the amount of dark pigment in the ventral pattern of Florida chicken

snakes. Specimens from the Panhandle east to the Suwannee River have

the darkest bellies.

Supralabial pigmentation. The geographic variation in the amount

of dark pigment on the upper labial scales in this species varies geo-

graphically as in Map 109. Its variation is almost identical to that

seen in ventral pigmentation except that snakes with dark supralabials

occur also on the Upper Keys.

Factor 1. The first factor accounts for 51.6% of the total varia-

tion in four characters, and most of the variation in ventral and supra-

labial pigmentation, as well as part of the variation in number of

dorsal blotches. Map 110 shows how this character varies within Florida.

Snakes from the Panhandle receive the highest factor scores, implying

darker labial and ventral pigment and fewer dorsal blotches.


Lampropeltis getulus (Linnaeus)

I analyzed data on 207 specimens of Lampropeltis getuZus from

Florida, southern Georgia and southern Alabama (Map 111). A total of

eleven characters were investigated for geographic variation (Appendix

A). Head length was divided by snout-vent length and the resulting

ratio found to correlate with snout-vent length. Further consideration

of this character has been omitted. The characters which seem to vary

geographically are discussed below.










Number of ventrals. The number of ventral scales in Florida king-

snakes does not correlate with sex (r = 0.1392). Therefore, the sexes

could be lumped to increase the sample size. Kingsnakes from the Panhandle

tend to have fewer ventrals than those from the peninsula. The tendency

is not pronounced, however, and if any geographic pattern of variation

exists within the peninsula, it does not emerge from examination of the

maps.

Number of subcaudals. Male L. getulus usually have more subcaudals

than females (r = 0.6306). There is little geographic concordance between

the sexes. There is a very generalized tendency for subcaudal counts to

be higher in the southern parts of the peninsula.

Percent tail. Tail length divided by total length varies as shown

in Maps 112 and 113. Males have proportionately longer tails than females

(r = 0.4837), thus the sexes have been treated separately in the geograph-

ical analysis. Snakes with proportionately longer tails occur in extreme

southern Florida and apparently the Apalachicola River Valley.

Dorsal scale rows. The number of scale rows at midbody varies geo-

graphically as shown in Map 114. Kingsnakes from the Panhandle east to

the vicinity of the Aucilla River have 21 midbody scale rows, while

specimens from the peninsula usually have 23. It is apparent that a

large percent of kingsnakes from extreme southern Florida have 21 scale

rows as well.

Number of infralabials. Most Florida kingsnakes have 18 lower

labial scales, counting both sides. However, many from extreme northern

parts of the state have 19 or 20 infralabial scales. In addition, king-

snakes from the east coast of the peninsula frequently have 20 lower

labials. See Map 115.










Number of cross bands. Maps 116, 117, and 118 show the geographic

variation in the number of dorsal precaudal cross bands in Florida L.

getulus. The concordance between the sexes is remarkable, and suggests

that the sexes are responding similarly to whatever environmental factor

selects for cross band counts. There is a very weak (r = 0.4038)

correlation between snout-vent length and number of cross bands, implying

that larger snakes tend to have fewer cross bands. In the present case,

however, there is no correlation between snout-vent length and latitude

in Florida (r = 0.1678), so the variation described is not due to

variation in snout-vent length, but to inherent variation in cross

band counts. In other words, snout-vent length does not vary geograph-

ically in Florida, based on the present sample. The number of cross

bands increasesin regular dine southward on the Florida peninsula.

Dorsal pattern. The amount of light pigment in the dorsal pattern

of Florida kingsnakes varies geographically as shown in Maps 119, 120,

and 121. Congruence between the sexes is quite good. Areas in which

the kingsnakes tend to have more light pigment dorsally include the

Everglades and southern peninsula, the Lower Apalachicola Valley, and

extreme northern Florida. Frequently, the kingsnakes from the region

to the east of Tampa Bay are light colored, as well.

Factor 2. The second factor accounts for 27% of the total varia-

tion in five characters, and much of the variation in number of ventrals

and midbody scale rows. Map 122 shows the geographic variation for this

multivariate character. Specimens with higher factor 2 scores tend

usually to occur in the peninsula as opposed to the Panhandle.

Factor 3. Factor 3 accounts for 23% of the total variation in

five characters, and much of the variation in dorsal scale rows and









light pigment in the pattern. Snakes from extreme northern Florida,

parts of southern Florida, and certain other regions in the peninsula

have high factor 3 scores. See Map 123.


Lampropeltis triangulum (Lacepede)

I analyzed data on 120 specimens of La'propeltis triangulum from

Florida, southern Georgia and southern Alabama (Map 124) looking for

trends of geographic variation in each of 15 characters (Appendix A).

None of the characters investigated showed correlations with snout-vent

length. Those characters which seem to vary geographically are discussed

below.

Number of ventrals. Males and females do not differ appreciably in

number of ventral scales (r = 0.2330). However they do seem to differ in

their patterns of geographic variation. Sample sizes are admittedly small,

and trends uncovered by the mapping techniques may be a result of sampling

bias. However, based on the data available (Maps 125 and 126) male milk

snakes seem to have higher ventral counts in northern Florida and the

peninsula, while females have lower counts there.

Number of subcaudals. Males generally have more subcaudal scales

than females (r = 0.6352). Maps 127 and 128 show the geographic variation

of this character. Concordance between the sexes is fair. If there is

any geographic tendency, it is for snakes from the Panhandle and parts of

southern Florida around Lake Okeechobee to have higher subcaudal counts.

Ventrals plus caudals. The summation of the proceeding two charac-

ters does not correlate with sex (r = 0.1106), and samples could be lumped

to produce Map 131. In addition, Maps 129 and 130 are provided to show










the degree of correspondence between the sexes. Generally speaking,

milk snakes from the Panhandle have higher ventral and caudal counts

than specimens from most of the peninsula. However, snakes from the

east coast and areas around Lake Okeechobee seem to have high ventral

plus caudal counts as well.

Percent tail. Relative tail length varies geographically as

shown in Maps 132 and 133. Males have proportionately longer tails

(r = 0.6537). The variation does not have a clear-cut pattern, but there

seems to be a slight tendency for relative tail length to increase clinally

to the south on the Florida peninsula.

Dorsal scale rows. Female L. trianguZwn from Florida usually have

19 midbody scale rows, while males may have either 19 or 17. Maps 134

and 135 show the geographic variation in midbody scale rows. Male

specimens from the Panhandle usually have 19 scale rows at midbody, and

males from the peninsula may have either 19 or 17.

Body bands. The number of red precaudal cross bands varies geo-

graphically as shown in Maps 136, 137, and 138. High band counts are

associated with milk snakes from northern Florida, including the Pan-

handle, the area east of Tampa Bay on the central Highlands, and apparently,

the region around Miami in southern Florida.

Tail bands. Maps 139, 140, and 141 show the geographic variation

in number of red tail cross bands in Florida milk snakes. In general,

specimens from the Panhandle and northern peninsula have higher tail

band counts than those from the remainder of the state.

Total bands. The summation of precaudal and caudal red bands

varies geographically as shown in Map 142. Highest counts occur on










snakes from northern Florida, the area east of Tampa Bay and the south-

eastern peninsula region. Milk snakes from the southern half of the

peninsula (not counting the Miami rim area) have low band counts com-

pared with specimens from the Panhandle and northern half of the penin-

sula.

Factor 3. This multivariate character accounts for 16.6% of the

total variation in 10 characters and most of the variation in the number

of red cross bands on the body and the tail. Its variation is shown in

Map 143 and is very similar to the variation seen in total band counts.


Diadophis punctatus (Linnaeus)

I examined 295 specimens of Diadophis punctatus from Florida,

southern Georgia and southern Alabama (Map 144) for potential geographic

variation in each of 23 characters (see Appendix A). None of the

characters examined was found to be correlated with body size. Those

characteristics which show apparent patterns of geographic variation

are discussed below.

Number of ventrals. Maps 145 and 146 show the geographic variation

in ventral numbers for male and female ringneck snakes from Florida. The

correlation coefficient between ventral counts and sex was found to be

0.6314. Snakes from the Panhandle and northern peninsula have the highest

ventral counts. Concordance between the sexes is very good.

Number of subcaudals. Males have more subcaudal scales than females

(r = 0.7425). The geographic variation in subcaudal counts is presented

in Maps 147 and 148. Its variation is more complex than that observed in

ventral count variation.


I









Ventrals plus caudals. The summation of ventrals and subcaudals

is not correlated with sex (r = 0.0624), and the samples could be lumped

to produce Map 149. The highest ventral scute counts occur in snakes

from the Panhandle and northern peninsula. Snakes with intermediate

values occur in the southern tip of the peninsula, and specimens with

low ventral plus caudal counts are found on the Lower Keys and most of

the south-central Florida peninsula.

Percent tail. Relative tail length was found to be correlated

with sex (r = 0.8058), and the males and females have been mapped

separately (Maps 150 and 151). Generally speaking, Diadophis from the

southern half of the peninsula and the Keys have proportionately longer

tails than specimens from the remainder of the state.

Numer of supralabials. Most southeastern ringneck snakes have 16

total supralabial scales. Occasional specimens have only 14 upper labials,

and these tend to occur more frequently in the Panhandle and northern parts

of the Florida peninsula. See Map 152.

Subcaudal spots. The number of small black spots on the underside

of the tail varies geographically as shown in Map 153. Diadophis

punctatus from the Florida Panhandle, the Gulf Hammock region and the

Lower Keys often have such spots. Specimens from the remainder of the

state usually lack these black spots.

Labial pigmentation. Pigment on the labials of Florida D. punctatus

may be in discrete spots, diffuse smudges or lacking altogether. Map 154

shows the geographic variation of this character for both sexes of Florida

ringnecks. Specimens from the Lower Keys have no such pigment or it is

very diffuse. Specimens from the southern Everglades and parts of the









Gulf Hammock region usually have diffuse labial pigment. The majority

of Florida ringneck snakes have labial pigment confined to discrete

spots.

Pigmented supralabials. The number of upper labial scales with

black pigment varies geographically as in Maps 155, 156, and 157.

Specimens from South Florida and the Keys as well as many from the Gulf

Hammock region score high for this character. Snakes from the Panhandle

have the lowest states for this character, while specimens from the

remainder of the state receive intermediate scores for number of pigmented

supralabials.

Pigmented labials. This character is the summation of labials,

supra- and infra, with black pigment. Its geography is depicted in

Map 158. Ringneck snakes from the Gulf Hammock region and the southern

tip of the peninsula including the Keys have the highest states for

this character. Specimens from the Panhandle have the least pigment

on the labials and most peninsular specimens are intermediate for pig-

mented labials.

Ring interruption. Most ringneck snakes from the Florida peninsula

have a middorsal break in the neck ring. Map 159 shows, however, that

the geographic variation in this character is more complex. Specimens

from the Lower Keys and the Gulf Hammock may lack a nuchal ring alto-

gether. Many ringnecks from coastal areas do not have a middorsal ring

interruption. Most Diadophis from the Panhandle have complete neck

rings.

Ring width. The width of the nuchal ring varies geographically as

shown in Maps 160, 161, and 162. Diadophis from the Panhandle and northern

parts of the peninsula have the widest nuchal rings.









Ring displacement. The position of the nuchal ring relative to

the parietal scales varies geographically as shown in Map 163. Snakes

from the Panhandle and northern peninsula tend to have their neck rings

originating nearer to the parietals than do more southerly specimens.

Factor 2. The second factor extracted from a matrix of 19

characters accounted for 13.2% of the total variation, and much of the

variation in number of pigmented supralabials and infralabials as well

as labial pigmentation type. Map 164 shows that Diadophis from the

Gulf Hammock region and the southern peninsula including the Keys have

the highest scores for factor 2. Snakes from the Panhandle have the

lowest scores, and specimens from the remainder of the peninsula have

intermediate values.

Factor 4. This multivariate character describes 7.8% of the

variation in 19 characters as well as part of the variation in numbers

of labials with pigment. Again, high factor 4 scores are associated with

snakes from the Gulf Hammock region and the Keys. Snakes from most of

the Panhandle and northern peninsula get low scores for this factor,

implying wider, interrupted, more anterior rings. Map 165 shows the

geographic variation of factor 4.


Cemophora coccinea (Blumenbach)

I analyzed data on 90 specimens of Cemophora coccinea from Florida

and southern Georgia (Map 166) for geographic variation in each of 17

characters (Appendix A). The sample size is unfortunately small. The

characters examined which seem to have patterns of geographic variation

are discussed below.









Number of ventrals. The number of ventral scales in Florida

scarlet snakes correlates with sex (r = 0.4144), and the sexes have been

mapped separately (Maps 167 and 168). The correspondence between the

sexes is very good. Sample sizes are small, but scarlet snakes from

the Panhandle and the southern end of the peninsula tend to have fewer

ventral scales than specimens from the middle of the peninsula.

Number of subcaudals. Maps 169 and 170 show the geographic variation

for male and female Cemophora subcaudal counts. The number of subcaudals

correlates only weakly with sex (r = 0.3385), with males having the higher

counts. In both sexes, snakes from the Panhandle tend to have fewer

subcaudals than specimens from the peninsula. The sample sizes are

small, but it seems that specimens from the southern tip of the state

also have low subcaudal counts.

Ventrals plus caudals. This character summarizes nicely the

variation apparent in the two proceeding counts, and is not correlated

with sex (r = 0.2240). Map 171 shows the pattern of geographic varia-

tion in ventral plus caudal counts for both sexes of Florida C. coccinea.

Lowest counts are associated with snakes from the Panhandle east to the

Suwannee River and from the southern end of the peninsula, south of

Lake Okeechobee. Scarlet snakes from the remainder of the peninsula

between the Suwannee River and Lake Okeechobee have higher ventral scute

counts.

Percent tail. Tail length divided by total length varies geograph-

ically as shown in Maps 172 and 173. There is no significant difference

between relative tail lengths in the two sexes for this species. In

general, scarlet snakes from more southern localities tend to have pro-










portionately longer tails, although the tendency is not sharply defined.

In the Panhandle, females have relatively longer tails, but males have

shorter tails. The result of this is that sexual dimorphism is pronounced

in the few Panhandle specimens examined but lacking in the peninsular

specimens. The two Panhandle females have longer tail length/snout vent

ratios (mean = 0.158) than the three males available (mean = 0.140).

Infralabials. Florida C. coccinea may have 14, 16 or 18 lower

labial scales. Specimens from the Everglades Region frequently have

14 infralabials, while many specimens from the central and north-central

peninsula have 18.

Supralabials. Map 174 shows the geographic variation in the number

of supralabial scales in Florida Cemophora. Snakes from the Panhandle

west of the Aucilla River, northeast Florida, and the Everglades usually

have 11 to 13 upper labials. Snakes from the central peninsula tend to

have 14 or 15.

Number of red body bands. Map 181 depicts geographic variation in

the number of red cross bands in Florida scarlet snakes. Snakes from

northern Florida and the Osceola National Forest region, just south of

Tampa Bay, and the Everglades have fewer cross bands than snakes from

the rest of the state.

Number of red tail bands. The number of cross bands on the tail in

Florida Cemophora correlates with sex (r = 0.5179). Maps 182 and 183

show the nature of variation in this character. Although concordance

between the sexes is poorly developed, a general tendency for scarlet

snakes from more northern localities to have more tail bands is apparent.










Dorsal scale rows. Ninety and four-tenths percent of Florida

Cemophora have 19 dorsal scale rows at mid body. Specimens studied from

the Everglades have 17 anterior scale rows, and specimens from extreme

northern Florida tend to have 21, while those from the remainder of

Florida usually have 19 anterior scale rows. All Cemophora examined

from the Panhandle have 19 posterior scale rows. In the peninsula,

many specimens have fewer than 19. See Maps 175 and 176.

Length of the white bands. Maps 177, 178, and 179 show the vari-

ation in the length (in scale-lengths) of the first and fifth white

bands in Florida Cemophora. The geographic patterns will be discussed

multivariately under factor 1.

Length of red bands. There seems to be three areas where longer

red bands are the rule: northern Florida, especially the northern parts

of the Panhandle, around Lake Okeechobee, and the extreme southern

Everglades. See Map 180.

Number of red cross bands. The only consistent tendency between

the sexes in the geography of the variation in number of red body bands

is that specimens from the Everglades region usually have fewer such bands

(Map 181). The number of tail bands varies geographically as shown in

Maps 182 and 183. In this character, it is difficult to discern a pattern

that is common to both sexes.

Factor 1. The first factor accounts for 24.7% of the total variation

in 14 characters, and 80% of the variation in length of the first white

band and 64% of the variation in length of the fifth white band. Thus

factor 1 describes variation in the length of the white bands in C.

coccinea. Its geographic variation is figured in Map 184. Snakes from










the western Panhandle, north central peninsula, and west coast tend to

have longer white bands.

Factor 2. The second factor represents a multivariate assessment

of red bands in Cemophora. It accounts for much of the variation in

number of red body bands, and length of the first and fifth red bands.

It represents 16% of the total variation, and is mapped in Map 185.

The southern half of the peninsula tends to support populations of

scarlet snakes with fewer but longer red bands, while the pattern in the

rest of Florida is unclear.

Factor 3. Accounting for much of the variation in number of supra-

and infralabials and ventrals plus caudals, the third factor represents

13.5% of the total variation, and is figured in Map 186. The Panhandle

and north Florida as well as the Everglades are separated out with low

values for factor 3. These areas have cemophora with fewer labials and

fewer ventrals plus caudals.

Factor 4. This factor accounts for 10.3% of the total variation,

and gets high loadings from the three dorsal scale row variables.

Cemophora with higher scale row counts occur in much of the Panhandle

and northern half of the peninsula. See Map 187.


Tantilla coronata (Baird and Girard), Tantilla reZicta Telford, and
Tantilla oolitica Telford

I analyzed data on 198 specimens of Tantilla from Florida (Map 188)

for possible geographic variation in each of 11 characters (Appendix A).

Those characters which seem to vary geographically are discussed below.

Number of ventrals. Females generally have more ventrals than males

(r = 0.4150). The sexes have been mapped separately in Maps 189 and 190.










In both sexes, the number of ventral scales decreases southward on the

peninsula until the southernmost localities in Florida. Specimens examined

from Miami and Key Largo have high ventral counts, reminiscent of northern

populations.

Number of subcaudals. The highest subcaudal counts occur on snakes

from the Big Bend region of northern Florida and decrease quickly to the

west and more gradually to the south. Maps 191 and 192 show the variation

for males and females which differ in mean subcaudal counts (r = 0.4194).

Ventrals plus caudals. The summation of the proceeding two counts

produces a variable which does not correlate with sex (r = 0.0783). Maps

193, 194, and 195 show how this character varies geographically. Tantilla
from the Panhandle and northern peninsula have the highest counts, decreas-

ing clinally southward on the peninsula. Tantilla from the Miami area are

more like northern populations in this character, with higher ventral

scute counts.

Percent tail. Relative tail length varies geographically as shown

in Maps 196 and 197. Males usually have proportionately longer tails than

females (r = 0.6339). Both sexes vary geographically with relatively

longer tails occurring in populations inhabiting the Big Bend region and

the western coast of the peninsula.

Supralabials. Tantilla from Highlands County often have six

upper labials on each side, while specimens from the remainder of the

state usually have seven. Map 198 shows this variation.

Parietal pigmentation. TantiZta examined from the Miami area and

parts of the Big Bend region of northern Florida lack light spots on the

parietal scales. Maps 199, 200, and 201 show the geographic variation









of this character. Specimens from the Panhandle east to the Ochlockonee

River, Highlands County, and the lower east coast of the peninsula have

extensive parietal light markings, often forming a partial nuchal ring.

Snakes with intermediate amounts of light pigment in the parietal region

occur throughout most of the Florida peninsula.

Snout pigmentation. Map 202 shows the geographic variation in the

amount of light pigment on the snout in Florida Tantilla. Most specimens

examined from the lower east coast of the peninsula have a large white

spot on the rostral and internasal scales. Tantilla from Highlands

County have some light pigment on the snout, while the majority of

Tantilla populations studied lack this characteristic.

Factor 2. This multivariate character accounts for 18.1% of the

total variation in eight characters and most of the variation in number

of ventrals plus caudals and parietal and snout pigmentation. Map 203

summarizes the geographic variation in factor 2. The specimens examined

from the Miami area and the Big Bend region receive the highest factor 2

scores, implying reduced light pigmentation and more ventrals plus caudals

in these areas. Panhandle Tantilla and those from Highlands County have

the lowest factor 2 scores. Intermediate values are seen in specimens from

the remainder of the state.


Sistrnuus miliarius (Linnaeus)

I examined 320 specimens of Sistrurus miliarius from Florida,

southern Georgia and southern Alabama (Map 204) for possible variation

in each of 22 characters (see Appendix A). Much of the variation studied

in this species was very noisy owing to a large degree of individual










variation among snakes from nearby localities. Smoothing algorhythms

might help clarify the picture by plotting averages of adjacent specimens.

However, the mapping procedure employed here does not smooth, but rather

plots the data exactly as they appear. Three ratios concerned with the

frontal scale and snout-vent length were correlated with snout-vent

length and excluded from further consideration. Those characters for

which geographic trends were noted are discussed below.

Number of ventrals. Females tend to have more ventral scales than

males (r = 0.4672), and the sexes have been treated separately in Maps

205 and 206. The lowest ventral counts are apparently associated with

snakes from the Panhandle, while the highest occur in snakes from the

central peninsula.

Number of subcaudals. Males usually have more subcaudal scales

than females (r = 0.6267). Maps 207 and 208 show the geographic variation

in subcaudal counts for Florida pigmy rattlesnakes. The pattern is like

that seen in the variation of ventral counts. Specimens from the Panhandle

have the lowest counts, and specimens from the central part of the penin-

sula tend to have the most subcaudal scales. As with the proceeding

character, pigmys from the lowland region south of Lake Okeechobee tend

to have lower counts than specimens occurring just north and south of

this region.

Ventrals plus caudals. Although ventrals and caudals are both

correlated with sex, their summation is not (r = 0.0570). The variation

in this character is depicted in Map 209 for the combined sexes. Snakes

from the Panhandle east to the vicinity of the Aucilla River and in the

Everglades region south of Lake Okeechobee tend to have the lowest ventral









scute values. Sistrzrus from the peninsula excluding the Everglades seem

to show a clinal increase in ventral and subcaudal counts to the south.

Dorsal scale rows. Maps 210 and 211 show the geographic variation

in the number of dorsal scale rows at two points along the body in Florida

Sistrurus. The lowest scale counts tend to be associated with specimens

from the Florida Panhandle and the highest with specimens from coastal

areas along the peninsula. Snakes with intermediate counts occur in

most of the interior peninsula. A lot of individual variation among

snakes from closely separated localities creates the noisy surfaces

depicted in the maps.

Number of blotches. Pigmy rattlesnakes from the Panhandle west of

the Ochlockonee River and from many coastal areas on the peninsula

frequently have more dorsal body blotches than specimens from the

remainder of the study area. Maps 212 and 213 show the patterns of

geographic variation for male and female S. miliarius.

Spot/space ratio. This character varies geographically as shown

in Map 214. Pigmys occurring west of the Ochlockonee River in the Pan-

handle and in the Everglades usually have crossband-like body blotches

that are more narrow than their inter-blotch spaces. Snakes from coastal

areas in the peninsula tend to have larger blotches with very narrow

spaces between. Many specimens from interior localities on the penin-

sula have spot/space ratios intermediate between these.

Spot shape. When the length (in scale lengths) of a typical mid-

body dorsal blotch is divided by its width, the resulting ratio varies

geographically as depicted in Map 215. Sistrurus from the Panhandle and

Everglades tend to have dorsal blotches that are more like crossbands.

Specimens from most of the peninsula have blotches that are more roundish.










Dorsal contrast. Sist-urcs from the Panhandle and parts of south-

ern Florida including the Everglades have more contrast between their

dorsal blotches and their ground color, resulting in a more distinctive

dorsal pattern. There may also be a tendency for snakes from coastal

areas to have higher values for this character as well. See Map 216.

Ventral pigmentation. Pigmy rattlers from much of the Panhandle

west of the Ochlockonee and from South Florida tend to have more white

ventrally than specimens from the remainder of the state. The geographic

variation of this character is displayed in Maps 217 and 218.


Crotalus adamanteus Beauvois

I examined 194 specimens of Crotalus admnanteus from Florida (Map

219) for possible geographic variation in each of 18 characters (Appendix

A). There is a large amount of individual variation in most of the

characters examined. Patterns of geographic variation are obscured by

this individual variation, with the result that many of the maps appear

noisy. Several of the characters examined appeared not to vary geograph-

ically within the study area. Those for which geographic patterns could

be recognized are discussed below.

Number of ventrals. Female rattlesnakes usually have more ventral

scales than males (r = 0.6808). The only geographic trend apparent in the

variation of ventral counts is that snakes from the Florida Keys and adja-

cent mainland consistently have more ventrals than specimens from elsewhere

in the study area. There is apparently no dine within Florida.

Number of subcaudals. Males have more subcaudals than females (r =

0.7971). The variation in subcaudal counts within Florida is complex and

seems to have no geographic component based on the sample available.









Dorsal scale rows. I can discern no geographic trend in the vari-

ation of dorsal scale row counts in Florida C. adamanteus. Map 220 shows

the spotty occurrence of specimens with higher scale row counts.

Number of infralabials. The variation in this character is also

noisy, but some geographic trends appear to exist. Maps of the variation

in each sex are provided (Maps 221 and 222), and some correspondence is

apparent. Rattlesnakes from northern Florida and from the Lower Keys

typically have more lower labials than specimens from the central penin-

sula. Map 223 shows the variation in infralabial counts for the com-

bined sexes.

Dorsal blotches. The number of diamonds on Florida Crotatus varies

geographically as shown in Map 224. There seems to be a tendency for

specimens from the Panhandle, the Keys, and the west coast of the penin-

sula to have fewer dorsal blotches than specimens from interior localities

on the peninsula.

Labial pigmentation. The number of immaculate supralabials in

Florida C. adamanteus varies geographically as shown in Maps 225, 226,

and 227. There is a tendency for specimens from the western Panhandle,

the Upper Keys and the Everglades region to have dark pigmentation on all

upper labial scales. Rattlesnakes from the Central Ridge east of Tampa

Bay and from the Lower Keys frequently have the most immaculate labials.

Ventral pigmentation. Maps 228, 229, and 230 depict the geographic

variation in the degree of ventral dark smudging in Florida rattlesnakes.

There is a tendency for Crotalus from the Panhandle, the Everglades region

and the western coast of the peninsula to have lighter ventral patterns

than specimens from the interior of the peninsula. Snakes from the









Lower Keys usually have darker ventral patterns, more like specimens from

north-central Florida.

Factor 1. The first factor accounts for 16.7% of the total variation

in 14 characters, and most of the variation in labial pigmentation and the

number of immaculate supralabials. Map 231 shows its geographic variation

in Florida. Snakes from the western Panhandle, the Everglades region and

the Keys typically have darker supralabials. Specimens examined from the

Central Ridge consistently have the least labial pigmentation.

Factor 2. The second factor accounts for 12.8% of the total varia-

tion in 14 characters, and most of the variation in infralabial number.

Factor 2 also receives a contribution from the variation in the number of

supralabial scales. Map 232 shows how factor 2 varies geographically.

Specimens from the Florida Keys and parts of northern Florida tend to

receive higher factor 2 scores, and specimens from the southern half of

the peninsula usually score the lowest.

Environmental Data

I mapped environmental data from 196 weather stations in Florida,

Georgia and Alabama (Map 233). Maps 234 through 245 show the results of

the variables examined.

The Patterns

I used factor analysis to compare one hundred maps of morphological

variation in fifteen species of Florida snakes. The SPSS factor analysis

procedure extracted 24 factors (patterns of geographic variation) which

accounted for 76.9% of the total information in the maps. The maps









(characters) analyzed and their communalities (percentage of variation

accounted for) are presented in Table 1. Table 1 also gives the factor

(pattern of geographic variation) with which each character is most

closely associated.

Most of the geographic variation observed in Florida snakes is

distributed along a north-south axis. Factor 1 accounted for 26.7% of

the variation explained by the factor analysis procedure, and most of

the variation in those characters which showed distinct north-south

changes in character states. Of the 100 maps analyzed, factor 1 accounted

for more than half of the variation in ten maps, and was the principal

pattern of variation for 38 characters (Table 1). In all the maps,

factor 1 accounts for that part of the geographic variation that is

north-south oriented. Factor 1 actually identifies two important

patterns of geographic variation. The Suwannee River Pattern is shared

by those species which demonstrate distinct character state changes

occurring in the region of the present Suwannee River. The North-South

Pattern includes those species which show clinal changes in character

states southward on the Florida peninsula.

Table 2 presents the characters (maps) and their factor loadings

on factor 1. These factor loadings may be interpreted as the relative

importance of the various characters (i.e. maps) to the definition of the

factor. Their square is the percentage of variation accounted for by

the factor. The important observation to be made here is that nearly

all of the characters analyzed have a significant portion of their vari-

ation which may be described as a north-south gradient or a character

shift along north-south lines.









The North-South Pattern is the most important pattern of geographic

variation observed in Florida snakes. Table 2 presents the factor load-

ings for all maps analyzed. Even characters which are primarily varying

in some other pattern usually have some component of their variation which

can be described as north-south oriented. Many characters (e.g. ventrals

plus caudals in Storeria dekayi, Thamnophis sirtalis, Coluber constrictor,

Elaphe guttata, Lampropeltis getulus, Lampropeltis triangulrn, Cemophora

coccinea, Diadophis punctatus, and Sistrurus miliarius, and blotches or

crossbands in Elaphe guttata, Elaphe obsoleta, and Lwnpropettis getulus)

vary primarily in the North-South Pattern. Figure 3 diagrammatically

represents this important pattern of geographic variation.

The Suwannee River Pattern is presented in Figure 4, and is best

exemplified by the geographic variation observed in such characters as

midbody scale rows in Storeria dekayi, number of supralabials in

Thamnophis sacritus, midbody scale rows in Lampropeltis getulus, and

dorsal blotch development in Elaphe obsoleta. Like the North-South

Pattern, this pattern is occasionally superimposed on other patterns

of geographic variation (e.g. number of labial spots in Diadophis

punctatus).

The second factor extracted from the matrix of 100 maps accounted

for another large proportion of the information. Table 3 presents

factor loadings on factor 2 for the variables which were important in

its construction. This pattern of geographic variation may be called the

Everglades Pattern and is the principal pattern of variation for such

characters as the number of immaculate labials in Crotalus adamanteus,

development of the dorsal blotch border in Elaphe guttata, and number









of crossbands, number of infralabials, and length of the red bands in

Cemophora coccinea. A diagrammatic representation of the Everglades

Pattern is provided in Figure 5.

Factor 3 describes a North Florida-Lower Keys Pattern, and is

best illustrated by the variation seen in supralabial and gular black

pigmentation in Coluber constrictor, and number of preocular scales in

Storeria dekayi. This pattern is concerned with a phenetic resemblance

between populations in northern Florida, the region east of Tampa Bay

and the Lower Florida Keys. Ventral white in Coluber constrictor,

ventrals plus caudals in Storeria dekayi, and supralabial-loreal contact

in Coluber constrictor also have elements of this pattern in their

geographic variation. Factor loadings for significant characters are

presented in Table 4, and Figure 6 illustrates the Lower Keys Pattern.

The fourth factor is the principal pattern of variation for number

of infralabials in Masticophis flagellum, number of infralabials in

Lampropeltis triangulzu, and the amount of white in the ventral pattern

of Sistrurus miliarius. The Panhandle-Everglades Pattern describes the

situation in which infraspecific populations in the Florida Panhandle

and the Everglades region are more similar to each other than either is

to geographically intermediate populations. Spot shape in Sistrurus

miliarius, supralabial brown pigment in Coluber constrictor, and ring

separation in Diadophis punctatus also have elements of this pattern

in their geographic variation. Table 5 gives the factor loadings for

characters with significant contributions to factor 4, and Figure 7

illustrates the Panhandle-Everglades Pattern.

The Coastal Pattern is defined by factor 5, and illustrated in

Figure 9. Table 6 presents the factor loadings for important characters









varying in a coastal manner. Such characters as ventral pigmentation

in Elaphe guttata, dorsal blotch border in the same species, labial

pigmentation in Diadophis punctatus, dorsal scale rows in Sistrurus

miliarius, and body blotches in Sistrurus load highly on factor 5.

In this pattern, populations from coastal regions and the Florida Keys

(when they occur there) tend to form a phenetic entity distinct from

populations farther inland.

Factor 6 represents the Okeechobee Pattern and is illustrated in

Figure 8. This pattern of geographic variation is seen in the number

of midbody scale rows in Lcnpropeltis trianguZun, number of supralabial

scales in Florida tantilla, and nuchal pigmentation in Tantilla. The

Okeechobee Pattern is characterized by geographic variation in which the

region around Lake Okeechobee, and especially the high ridge immediately

to the west, is inhabited by snakes phenetically different from con-

specifics to the north and to the south. Table 7 gives the factor

loadings for important characters in factor 6.

The remaining factors produced by the statistical procedure account

for smaller amounts of the information in the maps, and their interpre-

tation is omitted.

The multivariate analysis of contour maps of geographic variation

in Florida snakes has shown that the variation can be reduced to seven

major patterns. There are other patterns, but these are of less importance,

and are shared by fewer species. For example, Thawnophis sau~itus ground

color is distinctive in the Gulf Hammock region of central Florida. This

character fell out of the analysis in factor 22, which also received

significant loadings from Crotalus adamanteus ventral pigmentation and









T. sauritus parietal spot size. However, factor 22 accounted for only

1.2% of the variation explained in the analysis. Tables 8 through 11

present the factor loadings on factors 7 through 10 for the characters

which showed correlations with these factors.

The major patterns of geographic variation in Florida snakes

(North-South Pattern, Suwannee River Pattern, Everglades Pattern, North

Florida-Lower Keys Pattern, Panhandle-Everglades Pattern, Coastal Pattern,

and Okeechobee Pattern) account for 60.4% of the information contained in

the original contour maps. The remaining information is partitioned into

lesser patterns, and in some cases represents variation unique to a

particular species or character.


The Correlations

In order to search for correlations between the patterns of geographic

variation and environmental factors, I analyzed 17 parameters of environ-

mental variation. When these variables were factor analyzed, three

factors were extracted that accounted for 74.4% of the variation. These

factors are clearly defined as 1) average temperature, 2) maximum summer

temperatures, and 3) average rainfall. When the factor analysis of the

snake morphological data was carried out, representative variables from

the climatic data matrix were included.

Average annual temperature loads vary highly on factor 1 (Table 1).

Inspection of Map 235 reveals that average annual temperature belongs in

the North-South Pattern. Thus the North-South Pattern of geographic

variation is highly correlated with mean annual temperature. Similarly,

The Panhandle-Everglades Pattern is correlated with mean annual rainfall,









and the Coastal Pattern is correlated with maximum summer temperatures

(Table 1).

Although correlation does not prove cause and effect, its existence

does suggest the possibility of just such a relationship. Until experi-

mental falsification is at hand, I would hypothesize that the influence of

mean annual temperature on morphological variation in Florida snakes is

a great one. Using the same line of reasoning, very high summer maximum

temperatures may be responsible for the Coastal Pattern of geographic

variation, and mean annual rainfall may influence snake morphology to

vary in the Panhandle-Everglades Pattern.

The remaining patterns of variation are not highly correlated with

any environmental variables tested. These patterns may be maintained

by some other environmental variables (biotic or physical) that were

not examined, or they may be remnants of previous environmental conditions.

If the latter were the case, then we would have to believe that present

selective regimes have been insufficient to direct changes in phenotypes

towards adaptation to present conditions. For example, the Suwannee

River Pattern does not seem to correlate with any of the environmental

variables tested. Snakes showing this pattern of geographic variation

may be a result of past adaptations to an insular environment during

Pleistocene high sea levels. The Florida peninsula is no longer an

island, but selection has not been strong enough to eliminate (or

"spread out") the abrupt character changes in the region of the former

"Suwannee Straits." Furthermore, adaptations acquired during periods

of former isolation may have been accompanied by reduced reproductive

compatibility with mainland populations. This process speciationn) would






61



tend to preserve character states in both populations even after they

became geographically rejoined. Such a pattern would not necessarily be

expected to correlate with any present environmental parameter, and

would have to be interpreted as a remnant of some past selective

influence.










Table 1. Variables used in the factor analysis, their
communalities, and the principal pattern to which
each belongs. Note that most of the variables
belong to several patterns, but only the principal
pattern is included here.


Variable
Storeria.Sclsmid
Storeria.Ventrum
Storeria.Temppig
Storeria.Tempornt
Storeria.Subocspt
Storeria.Ventcaud
Storeria. Preocs
Storeria.Postocs
Storeria.Blklabs
Sirtais. Parietal
Sirtais. Dorspot
Sirtalis. Ventcaud
Sirtalis.Suplabs
Sauritus.Parsize
Sauritus.Dorbrn
Sauritvs.Stripe
Sauritus. Ventcaud
Sauritus.Suplabs
CoZuber.Ventrum
coluber.Gulbrn
CoZuber. Gulbl k
Coluber.Slbrn
CoZuber.Slblk
CoZuber.Slloreal
CoZuber.Vencaud
Masticop. Phase
Masticop.Ventcaud
Masticop.Inflabs


Communality
.95369
.68403
.58571
.80744
.83800
.82341
.54303
.71416
.73975
.62678
.73091
.54009
.95685
.57189
.48245
.66962
.63856
.91204
.76578
.46922
.80162
.79836
.84235
.42071
.78969
.75184
.77890
.69603


Principal Pattern
Suwannee River
Suwannee River
Factor 20
Suwannee River
Suwannee River
North-South
Keys
Factor 13
Factor 18
Factor 9
Factor 9
North-South
Factor 13
Factor 22
None
Factor 19
Factor 22
Suwannee River
Everglades, Keys
None
Keys
None
Keys
Factor 19
North-South
Suwannee River
Factor 15
Panhandle-Everglades










Table 1 Continued.


Variable
Opheodry.Slpig
Opheodry.Keels2nd
Opheodry.Ventcaud
Opheodry.Inflabs
Guttata.Bodyspts
Guttata.Tailspts
Guttata.Sclsmid
Guttata.Ventrum
Guttata.Spotbord
Guttata.Checks
Guttata.Ventcaud
Obsoleta.Blotches
ObsoZeta. Stripe
ObsoZeta.Spot
ObsoZeta.Ventrum
ObsoZeta.Labpig
Getulus.Blotches
Getulus.Sclsmid
Getulus.Pattern
Getulus.Vencaud
Getulus.Inflabs
TrianguZ.Sclsmid
Triangul.Bodybnds
TrianguZ.Tailbnds
Triangul.Ventcaud
Triangul. Inflabs
TrianguZ. Loreals
Cemophor.Sclsant
Cemophor.Sclspost
Cemophor.Bodybnds
Cemophor.Tailbnds
Cemophor.5thred


Communality Principal Pattern
.51104 Factor 7
.76185 North-South, Factor 7
.75063 None
.54415 Factor 24
.62129 North-South
.58125 North-South
.40211 Factor 16
.54088 Coastal
.62571 Everglades
.39840 Coastal
.59094 North-South
.73191 North-South
.70248 Suwannee River
.81187 Suwannee River
.87962 Suwannee River
.84859 Suwannee River
.92423 North-South
.86965 Suwannee River
.70095 North-South, Everglades
.66946 North-South
.68396 Factor 10
.58845 Okeechobee
.74186 Factor 7
.74450 Factor 7
.77099 North-South
.76916 Panhandle-Everglades
.65063 Factor 11
.65221 Factor 20
.86221 Suwannee River, Everglades
.88621 Everglades
.77072 Factor 11
.77706 Everglades









Table 1 Continued.


Variable
Cemophor.5thwht
Cemophor.Suplabs
Canophor.Inflabs
Cemophor. Ventcaud
Diadophi. Ventrum
Diadophi. Spotshap
Diadophi.Ringsep
Diadophi. Ringwdth
Diadophi.Labpig
Diadophi.Clrvents
Diadophi. Ventcaud
Diadophi.Suplabs
Diadophi. Labspts
Tantill. Ilfour
TantiZla.Parietal
Tantilla.Snout
Tantilla.Nuchal
Tantilla.Ventcaud
Tantilla.Suplabs
Sisatur. Bodyspts
Sistruru.Tailbnds
Sistruru.Sclsant
Sistruru.Sclsmid
Sistzuru.Contrast
Sistruru.Ventrum
Sistruru.Ventcaud.
Sistruu. Suplabs
Sistruru. Inflabs
Sistruwu.Sptshape
Sistruru. Sptspace
Cvotalus.Diamonds


Communality
.86478
.92083
.86708
.85531
.68257
.58628
.51227
.52656
.59992
.55130
.57328
.30275
.64861
.65249
.77002
.65309
.71403
.80101
.77949
.53895
.44302
.71182
.46439
.40396
.46360
.75488
.50758
.49931
.56716
.52296
.55132


Principal Patterns
Suwannee River
Suwannee River
Everglades
North-South, Everglades
Factor 8
Factor 8
Suwannee River, Panhandle-Everglades
Suwannee River
Coastal
Factor 8
North-South
Suwannee River
North-South, Suwannee River
Factor 23
North-South
Factor 7
Okeechobee
North-South
Okeechobee
Factor 19
Factor 19
North-South
Factor 18
Factor 21
Panhandle, Everglades
North-South
Factor 17
Factor 17
North-South, Panhandle-Everglades
North-South
Factor 14










Table 1 Continued.


Variable

Crotalus.Blkcauds
Crotalus .Ventrum
Crotalus. Clrlabs
Crotalus. Ventcaud
Crotalus.Suplabs
CrotaZus.Inflabs
Florida.Anntemp
Florida.Annrain
Florida.over 90


Communality

.41927
.51970
.44236
.48915
.70976
.61233
.76211
.59495
.67363


Principal Patterns

None
Factor 22
Everglades, Panhandle-Everglades
Factor 23
Factor 12
Factor 12
North-South
Panhandle-Everglades
Coastal










Table 2. North-South pattern and Suwannee River
pattern (Factor 1). Variables followed by
an asterisk (*) have factor 1 as their
principal pattern.


Variable

Storeri. Sclsmid*
Storeria. Ventrum*
Storeria.Tempig
Storeria.Tempornt*
Storeria.Supocspt*
Storeria.Ventcaud*
Storeria.Preocs
Storeria.Postocs
Storeria.Blklabs
Sirtalis.Parietal
Sirtalis.Dorspt
Sirtalis. Ventcaud*
Sirtalis. Suplabs
Sauritus.Parsize
Sauritus.Dorbrn
Sauritus.Stripe
Sauritus. Ventcaud
Sauritus. Suplabs*
Coluber.Ventrum
Coluber. Gulbrn
Coluber.Gulblk
Coluber.Slbrn
Coluber.Slblk
Coluber.Slloreal
Coluber.Ventcaud*
Masticop. Phase*
Masticop.Ventcaud
Masticop.Inflabs
Opheodry.Slpig
Opheodry.Keels2nd*


Factor Loading
0.88912
0.58711
0.03903
0.73400
0.59878
0.68715
0.09941
0.02662
0.15218
0.17929
0.02442
0.50298
0.23957
0.02563
0.24255
0.03231
0.30364
0.77160
0.29000
0.36889
0.01574
0.34031
0.03129
0.13485
0.73851
0.39039
0.31311
0.01632
0.26689
0.48867









Table 2 Continued

Variable
Opheodry. Ventcaud
Opheodry. Inflabs
Guttata.Bodyspts*
Guttata.Tailspts*
Guttata. Sclsmid
Guttat. Ventrum
Guttata. Spotbord
Guttata. Checks
Guttata.Ventcaud*
Obsoleta. Blotches*
Obsoleta. Stripe*
Obsoleta.Spot*
Obsoleta. Ventrum*
Obsoleta.Labpig*
GetuZus.Bloaches*
Getulus. Sclsmid*
GetuZus.Pattern*
GetuZus.Ventcaud*
Getulus.Inflabs
TrianguZ. Sclsmid
TrianguZ. Bodybnds
TrianguZ. Tailbuds
Triangul.Ventcaud*
Triangul. Inflabs
Triangul. Loreals
Cemophor. Sclsant
Cemophor.Sclspost*
Cemophor.Bodybnds
Cemophor.Tailbnds
Cemophor. 5thred
Cemophor. 5thwht*
Cemophor. Suplabs*
Cemophor.Inflabs


Factor Loading

0.31820
0.08321
0.51736
0.38104
0.06079
0.35622
-0.03501
0.01880
0.45058
0.70040
0.68599
0.81544
0.84751
0.84396
0.77272
0.78203
0.38190
0.47711
0.00146
0.30452
0.23409
0.28188
0.43181
0.29109
0.14573
0.16574
0.45041
0.08845
0.31636
0.25570
0.49114
0.72762
0.05655










Table 2 Continued


Variable

Cenophor.Ventcaud*
Diadophi.Ventrum
Diadophi.Sptshape
Diadophi. Ringsep*
Diadophi.Ringwdth*
Diadophi. Labpig
Diadophi.Clrvents
Diadophi.Ventcaud*
Diadophi.Suplabs*
Diadophi.Labspts*
Tantilla.Ilfour
Tanti la.Parietal*
Tantilla.Snout
Tantillta.Nuchal
Tantilla.Ventcaud*
TantiZa. Suplabs
Sistruru.Bodyspts
Sistn ru.Tailbnds
Sistruru.Sc1sant*
Sistrru. Sclsmi d
Sistruru. Contrast
Sistruru.Ventrum
Sistruru.Ventcaud*
Sistruru.Suplabs
Sistruru. Inflabs
Sistruru.Sptshape*
Sistruru.Sptspace*
CrotaZus.Diamonds
Crotais- Bl1kcauds
Crotalus.Ventrum
Crotaluz.C1rlabs


Factor Loading

0.53298
0.00094
0.20558
0.30422
0.53219
0.15822
0.05158
0.58642
0.31443
0.41560
0.17786
0.40090
0.35250
0.20308
0.55866
0.03635
0.07901
0.15767
0.48877
0.28273
0.30038
0.01047
0.58554
0.16292
0.15802
0.42178
0.41702
0.14065
0.18888
0.05286
0.17053









Table 2 Continued


Variable Factor Loading

CrotaZus.Ventcaud 0.14411
CrotaZus.Suplabs 0.10392
CrotaZus.Inflabs 0.20077
Florida.Anntemp* 0.82022
Florida.Annrain 0.35357
Florida.Over 90 0.23942














Table 3. Everglades pattern (Factor 2). Variables
followed by an asterisk have factor 2 as
their principal pattern.


Variable

Coluber.Ventrum
Guttata.Spotbord
Guttata.Ventcaud
Getulus. Pattern
Cemophor.Sclspost
Cemophor. Bodybnds*
Cemophor.5thred*
Cemophor.Inflabs*
Cemophor.Ventcaud
CrotaZus.Clrlabs*


-Factor Loading
0.42099
0.45133
0.29934
0.28488
0.37496
0.74285
0.56371
0.84919
0.45206
0.36125


__














Table 4. Keys pattern (Factor 3). Variables followed
by an asterisk have factor 3 as their principal
pattern.


Variable
Storeria.Ventcaud
Storeria.Preocs*
Storeria.Blklabs
Coluber.Ventrum
Coluber.Gulblk*
Coluber.Slblk*
CoZuber.Slbrn
Coluber.Slloreal
Opheodry.Ventcaud


Factor Loading
0.23989
0.40677
0.23295
0.45636
0.85700
0.88389
0.32688
0.28467
0.27052


--------














Table 5. Panhandle-Everglades pattern (Factor 4).
Variables followed by an asterisk (*) have
factor 4 as their principal pattern.


Variable
Masticop. Phase
Masticop.Inflabs*
Opheodry.Ventcaud
Opheodry.Keels2nd
Guttata.Bodyspts
Triangul.Inflabs*
Triangul. Ventcaud
Diadophi.Ringsep
Tantilla.Suplabs
Sistruru.Ventrum*
Sistruru.Sptshape
Crotaus. Blkcauds
CrotaZus.Clrlabs
Florida.Annrain*


Factor Loading
0.31427
0.72896
0.28898
0.24849
0.27224
0.46470
0.27908
0.30168
0.28222
0.44881
0.31826
0.26556
0.30508
0.37981


I













Table 6. Coastal pattern (Factor 5). Variables followed
by an asterisk (*) have factor 5 as their
principal pattern.


Variable
Masticop.Phase
Guttata.Ventrum*
Guttata.Spotbord
Guttata.Checks*
Diadophi. Labpig*
Sistruru.Bodyspts
Sistruru.Sclsant
Florida.over 90*
Sistruru.Sclsmid
Triangul.Sclsmid
CrotaZus.Clrlabs


Factor Loading
0.28903
0.46907
0.34480
0.61322
0.44062
0.25744
0.34333
0.40011
0.22124
0.23046
0.24009












Table 7. Okeechobee pattern (Factor 6). Variables
followed by an asterisk (*) have factor 6
as their principal pattern.


Variable
Storeria.Temppig
Sauritus. Stripe
Opheodrys Inflabs
Guttata.Ventrum
Getulus. Ventcaud
Traingul.Sclsmid*
Tantilla.Nuchal*
TantilZa.Ventcaud
Tantilla.Suplabs*
Tantilla. Ilfour


Factor Loading
0.28584
0.25478
0.23024
0.23154
0.25687
0.41243
0.71364
0.41977
0.65938
0.23273










Table 8. Factor 7. Variables followed by an asterisk
(*) have factor 7 as their principal pattern.


Variable


Sauritus.Parsize
Sauritus. Ventcaud
Coluber.Ventrum
Coluber.Slloreal
Masticop. Phase
Opheodry.Slpig*
Opheodry. Keels2nd
Guttata. Ventcaud
Getulus.Blotches
Getulus. Pattern
Triangul. Bodybnds*
Triangul.Tailbnds*
Cemophor.Bodyspts
Cemophor.Suplabs
Tantilla. Snout*
Tantilla.Ventcaud
Sistruru.Sclsant
Sistruru. Sc smid
Sistruru. Spotspac
Crotalus.Blkcauds
Florida.Anntemp


Factor Loading

0.24072
0.33728
0.25387
0.23442
0.28746
0.43284
0.44881
0.27252
0.36369
0.34378
0.71653
0.61504
0.22212
0.26222
0.60343
0.29430
0.33893
0.25518
0.29105
0.24405
0.32135














Table 9. Factor 8. Variables followed by an asterisk
(*) have factor 8 as their principal pattern.


Variable
Storeria.Blklabs

Diadophi. Ventrum*

Diadophi. Sptshape*

Diadophi. Clrvents*


Factor Loading
0.32766

0.77950

0.67326

0.63635














Table 10. Factor 9. Variables followed by an asterisk
(*) have factor 9 as their principal pattern.


Variables

Cemophor.5thred

Diadophi. Ringsep

Diadophi. Labspts

Storeria.Postovd

Sirtalis.Parietal*

Sirtalis.Dorspot*

Sirtalis.Ventcaud

Sauritus.Dorbrn

Sauritus. Stripe

Opheodry. Ventcaud*


Factor Loading

0.32272

0.27036

0.28795

0.28601

0.71245

0.79233

0.29031

0.27573

0.24338

0.33016












Table 11. Factor 10. Variable followed by an
asterisk (*) has factor 10 as its principal
pattern.


Variable
Storeria.Ventcaud

Guttata.Bodyspts

Guttata.Tailspts

Getulus.Inflabs*

TrianguZ.Sclsmid

Triangul. Inflabs


Factor Loading
0.27751

0.24571

0.25619

0.74571

0.28497

0.53247





















































Figure 3. North-South Pattern (Factor 1, in part).


















































Figure 4. Suwannee River Pattern (Factor 1, in part).

















































Figure 5. Everglades Pattern (Factor 2).
















































Figure 6. Keys Pattern (Factor 3).














































Figure 7. Panhandle-Evergladers PattPrn (Factcr 4).



















































Figure 8. Okeechobee Pttern (Factor 5).















































Figure 9. Coastal Pattern (Factor 6).











06




















--------------------

------ ----------






~----------------
--------------- ------------------ ---
~---------------------------------
~------ ---------------------------------------------

------- ------------- :::::::

--- ------ --- -- ;-1 1r,-- :----:-:_:: :_:::_ ::::_

------------- ------------

~--------------------------- ---------
..... .......-----------.... .......... .. . . ...-.-.................. ..










~-----------------------------------~-
i] ] .............. .............. ]]]] ]:2 i_]]]]]] ]]]]]]-]]i] ]]]]K ]]]K ] -:!]K ]]] ] ]





.. . .. . .... .. . .. .... .. ... -. .

















...................... ..~.~. ............. ...........
~~~~~ ~~.. ............ ...




















- -- - - -

~-----------------------------------





----------





~.------- --- -----------
~~.--- ------------- -------------------------------- ---------- ----- ----------
------- ------ ----- ---- - ------------------------- ---------------- --
S.~. ...... ~ -.--.... ~...........~............................ ........................~ ~



























RAP 1. Localities of 151 Storeria dekayi specimens

examined. An asterisk represents one specimen; an S

represents more than one.







87







I ------------ "--- *i i *-- --- --- -------.-..- - -


























as- - -













MAP 2. Geographic variation in number of ventral scales in
Storeria dekayi, males only. Levels by increased shading are:
124-131, 132-138, 139-145, 146-153. Based on 69 specimens.





________ ___F____~__ r___l_____l___ __F______ lCI__~_1___


___r_~_l___~ C___1_11__I


- - -.













MAP 3. Geographic variation in number of ventral scales in
Storeria dekayi, females only. Levels by increasing shading
are: 126-i31, 132-139, 139-145, 116-152. Based on 80 speci-
mens.






39



..-~c...-.. r-.-...~- -----.--- c-~--.---~------- ----------------- ----- -----:

I ----- ------
^ i l l l l l l l l i l::: . . .. . . .: :... .
................. ................ .........



.-.-
..... :* :... "



















MAP 4. Geographic variation in number of subcaudal scales in
Storeria dekayi, males only. Levels by increasing shading are:
50-56, 57-63, 64-70, 71-77. Eased on 63 specimens.
________--__ A -













1







90













-- --------------- --------.--------




















moo= 7:. .. .. ii
--. --. -- --.-..











MAP 5. Geographic variation in number of subcaudal scales
in Storeria dekayi, females only. Levels by increasing
shading are: 43-9, 50-55, 56-61, 62-68. Based on 77
specimens.

















O ml .......... ... .. ................






































MAP 6. Geographic variation in the sum of ventrals plus
caudals in Storeria dekayi, both sexes. Levels by increasing
shading are: 169-186, 187-200, 201-215, 216-227. Based on
138 specimens.
1-. -'




























138 specimens.







92











----------------------------- ----- ----- -
































MAP 7. Geographic variation in tail length divided by total
length in Storeria dekayi, males only. Darker shading repre-
sents proportionately longer talIs. Based on 67 specimens.
MAP 7. Geographic variation in tail length divided by total
length in Storeria dekayi, males only. Darker shading repre-
sents proportionately longer tails. Based on 67 specimens.





























































MAP 8. Geographic variation in tail length divided by
total length in Storeria dekayi, females only. Darker shading
represents proportionately longer tails. Based on 75 specimens.


I


-- ------------- ------ --------- --- ---------- ---- ------------ -------


_~_~... ........ .... 1/1.i

1^11... ,,~_L----~1 H,. ,,,, H..
.... in|,., .. ., ,u..


~I-m--___ I_-___i-- ll-..., ...... IIIIII 1-_iiiii
~^-IIlfL_ L~--1-11 1--.___1 I--lil- Ls--l. .I. iiiiiiii iii
C-~~~~~~ ~ ~ ~ -I'"_-_-II i.iiiiii It-._i_'--__~ -C


---------- I-----------.---- ----- ----


I




I






















I







94















........ ....




























represents 15 scale rows; darker shading represents 17.
Based on 151 specimens.



















...........







95





---------- ---- ----- ------------* ---+ --- ---- I----- ---*---4------- --- ---r--- ----- --- ---- ----a





































MAP 10. Geographic variation in number of preoculars (both
............iiii: ......... :::: ..... i




































sides) in Storeria dekavi, both sexes. Lighter shading repre-
-------- ----- ------------- --------- ----------------------------- --------~---- -----------


MAP 10. Geographic variation in number of preoculars (both
sides) in Storeria dekavi, both sexes. Lighter shading reore-
sents 2 preocular scales; darker shading represents 3 or 4.
Based on 149 specimens.





















.aaa..-i.e,aa .,.. ......... I.......*





















.
















~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ... ...s ........... --- ---s--*--s --' -- *--*- i- ---*- - -







--------- ---------- _



MAP 11. Geographic variation in extent and development of
ventral dark pigment in Storeria dekayi, both sexes. Increased
shading represents increased dark pigment on the ventral sur-
face. Based on 149 specimens.




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