nest-site selection in the eastern box turtle, terrapene
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Eastern Illinois UniversityThe Keep
Masters Theses Student Theses & Publications
2003
Nest-Site Selection in the Eastern Box Turtle,Terrapene carolina carolina, in a Population inCentral IllinoisBeth FlitzEastern Illinois UniversityThis research is a product of the graduate program in Biological Sciences at Eastern Illinois University. Findout more about the program.
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Recommended CitationFlitz, Beth, "Nest-Site Selection in the Eastern Box Turtle, Terrapene carolina carolina, in a Population in Central Illinois" (2003).Masters Theses. 1389.https://thekeep.eiu.edu/theses/1389
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http://www.eiu.edu/~graduate/thesisreproduce.htm 12/4/2003
NEST-SITE SELECTION IN THE EASTERN BOX TURTLE, TERRAPENE
CAROLINA CAROLINA, IN A POPULATION IN CENTRAL ILLINOIS
BY
BETHFLITZ
THESIS
SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS
FOR THE DEGREE OF
MASTER'S OF BIOLOGICAL SCIENCES
IN THE GRADUATE SCHOOL, EASTERN ILLINOIS UNIVERSITY
CHARLESTON, ILLINOIS
2003
I HEREBY RECOMMEND THAT THIS THESIS BE ACCEPTED AS FULFILLING
THIS PART OF THE GRADUATE DEGREE CITED ABOVE
DATE
DATE
Abstract
Nest site selection in turtles might allow females to increase the survival of their
offspring but little is known about the variables that influence that choice. I examined the
microhabitat variables at nest sites of the eastern box turtle, Terrapene carolina carolina,
at a Boy Scout camp in Shelby County, Illinois, to determine if females chose nest sites
that differed from random sites within the camp. Nest sites differed from random sites in
vegetation height and composition, percentage ground and canopy cover, and light
intensity. All females placed their nests in open habitat within the camp or a pasture
bordering the camp. I suggest that, due to the importance of incubation temperature on
hatchling development, open sites were selected due to the higher incubation
temperatures they provide.
11
Acknowledgments
I would like to acknowledge the following people for their help in the completion
of this project: Dr. Stephen Mullin, Dr. Robert Fischer, Dr. Eric Bollinger, Theron
Tinker, Nelda Foster, the Boy Scouts of America, Lincoln Trails Council, Jacques Nuzzo,
Jane Seitz, Cora Allard, Crystal Flitz, and Sara Denham. Partial funding of this project
was provided by Eastern Illinois University, the Illinois Department of Natural
Resources, and the Chicago Herpetological Society.
1ll
Table of Contents
List of Tables v
List of Figures VI
Introduction 1
Literature Review 2
Materials and Methods 4
Results 8
Discussion 10
Conclusions 16
Bibliography 19
Appendix I 26
IV
List of Tables
Table 1. Mean and standard deviation values for carapace length (CL), plastron length
(PL), carapace depth (CD), and mass of eastern box turtles (Terrapene c. carolina)
measured at Rhodes-France Boy Scout Camp, Shelby County, Illinois, during Summer
2001.
Table 2. Kolmogorov-Smimov test results for features of nest sites (NS; n = 24) and
random sites (RS; n = 75) at Rhodes-France Boy Scout Camp, Shelby County, Illinois,
during Summer 2001.
v
List of Figures
Fig. 1. Occurrence of nesting in eastern box turtles (Terrapene carolina carolina) with
precipitation events at Rhodes-France Boy Scout Camp, Shelby County, Illinois in
Summer 2001.
Vl
Errata
1. The sentence beginning at the bottom of page 8 of this thesis should read as follows:
Half of the females (50 % ) constructed nests during or within 24 hours of a
precipitation event but there was no relationship between the occurrence of
rainfall and nesting activity <-x2 = 2.06, p = 0.72).
2. Figure I shown on page 11 of this thesis should be replaced with the following:
I precipitation (mm) • nest events x 100 6
• x ...5
1 75-
x ... 4 -a j = 50- x x xx ... 3 ~ it
·f • x ...2 i !lo •
25- • x • • ...1
• • 0 -- - • - il 0
I I I I - I I I I - I
150 155 160 165 170 175 180 185 190 195 200
Julian date
Fig. 1. Occurrence of nesting in eastern box turtles (Terrapene c. carolina) with
precipitation events at Rhodes-France Boy Scout Camp, Shelby County, Illinois in
Summer 2001. Each dot in the figure, even those near the origin, represent
precipitation having occurred.
3. The reader should interpret with caution, statements in the Discussion section concerning
the relationship between precipitation and nesting activity in eastern box turtles.
Introduction
Patterns of habitat selection are an important aspect of an animal's natural history
because of the potential impacts on individual fitness (offspring production, survivorship,
etc.). One critical component of habitat selection among oviparous taxa is nest site
selection. Developing embryos at selected sites often have a greater chance of survival
than those at random sites (Wilson 1998); thus, natural selection should favor the
evolution of nest-site selection (Schwarzkopf and Brooks 1987, Temple 1987, Shine &
Harlow 1996, Kolbe & Janzen 2002). Research has shown that many species of turtles
choose non-random sites for egg placement (e.g., Malaclemys terrapin [Burger and
Montevecchi 1975], Kinosternon baurii [Wilson 1998], Chelydra serpentina [Kolbe &
Janzen 2002]). The early life history stages of turtles are typically characterized by the
absence of post nesting parental care and high egg and hatchling mortality rates (Keller et
al. 1997). The choice of a nest site is important because it will influence the likelihood of
predation of both eggs and hatchlings as well as affect the temperature and moisture
content at which the eggs develop (Dodd 2001 ). The microhabitat (primarily soil
moisture content and temperature) surrounding the nest site has been shown to affect the
developmental rate (Cagle et al. 1993), the sex of offspring (Wilhoft et al. 1983), and
some fitness characteristics of the hatchlings like size and growth rate (Burger 1976,
Packard et al. 1985, Janzen 1993).
Gathering a sufficient amount of data on turtles to test life history theory has been
relatively slow and difficult, in part due to their longevity and secretive nature, and the
logistical difficulties when sampling during some or most of their life stages (Iverson
1990). However, box turtles have the potential to provide researchers with a large amount
1
of data on how reproductive traits affect the life histories oflong-lived organisms (Dodd
2001). With rare exception (Congello 1978, Nieuwolt 1996), the current understanding
about these aspects of turtle ecology is based on aquatic or semi-aquatic species (Tinkle
et al. 1981, Walker and Parmenter 1990, Brewster and Brewster 1991, Congdon et al.
1994, Wilson 1998). In this study I sought answers to the following questions: 1) Do
female eastern box turtles, Terrapene c. carolina place their eggs at sites at different
proportions than the available habitat? 2) What are the microhabitat variables of the nest
that differ from random sites?
Literature Review
Terrapene c. carolina is a small terrestrial turtle with a hinged plastron and a
keeled, high-domed carapace. Females can be distinguished from males by the usual lack
of red pigmentation in the eye, flat plastron (the male plastron is concave), and shorter,
more slender tails. Terrapene c. caro/ina is predominantly an open woodland species,
ranging from New England south to Georgia and west to Michigan, Illinois, Tennessee,
and northern Alabama. It is omnivorous, eating a wide variety of plants, small
invertebrates, and carrion (Ernst et al. 1994).
Box turtles are long-lived, sexual maturity is late, and annual reproduction is low.
Sexual maturity is reached in both sexes at 7-10 years and females usually produce only
one clutch of eggs a year, but may produce more, especially in captivity and in some
southern states (Dodd 2001). Courtship and mating usually begins in May and extends
through the summer into October (Ernst et al. 1994). Females are capable of storing
sperm in seminal receptacles, and have been known to produce fertile offspring up to four
2
years after copulation with a male (Ewing 1943). Nesting occurs from early May to
August depending on the latitude but generally occurs in June.
The exact criteria by which female turtles choose nest sites are unknown but
studies have shown that in some species, females will travel great distances from their
home ranges to nesting sites (Stickel 1950, 1989, Legler 1960, Landers et al. 1980,
Congdon et al. 1983, Diaz-Paniagua et al. 1995, Hall et al. 1999). Females also show
nest site fidelity, choosing locations within a few meters of previous years' sites
(Congdon et al. 1983, Stickel 1989). Nesting activity by female Terrapene begins in the
evening hours (1700-1900 h) and takes two to six hours to complete (Congello 1978).
Clutch size ranges from one to eleven eggs but averages four to five (Congello 1978,
Warner 1982, Ernst et al. 1994). Incubation times reported in the literature range widely
(e.g., 57-136 days; Allard 1948, Iverson 1977, Congello 1978) due to the fact that
developmental rate is temperature dependent (Ernst et al. 1994, Dodd 2001).
There are a number of studies that examined either habitat selection or
reproduction in Terrapene. Reagan (1974) studied habitat selection in the three-toed box
turtle (T. c. triunguis) but, except for the brief mention of an observation of a nesting
female, did not examine the microenvironment of nest sites. Nieuwolt (1996) examined
microhabitat selection in the western box turtle (T. ornata luteola), but did not include
nesting activity or nest-site selection. The same author later used reproduction in T.
ornata luteola to test optimal egg size theory (Nieuwolt-Dacanay 1997) but nest site
variables were not examined in this study.
Due to the relative difficulty in locating nesting females, most of the studies on
Terrapene nesting behavior have focused on captive populations (Bissett 1968, Riemer
3
1981, Messinger and Patton 1995). A five year study of nesting in captive T c. triungis
(Messinger and Patton 1995) described nesting behavior and nest site selection. Most
clutches were laid in open areas in direct sunlight but a few were laid in areas that never
received sunlight. However, the authors noted that the small size of the study area (31 x
34 m) limited the variety of nesting sites. Cahn (193 7), Allard (193 5), Bissett (1968),
Riemer (1981), and Ernst et al. (1994) all provide mostly anecdotal data on nesting
behavior and nest site characteristics. Congello (1978) provides a detailed description of
nesting and egg laying behavior in both wild and captive T c. carolina. The study found
that selection took place from 1700-1900 h and occurred in a cleared area where sunlight
could penetrate the canopy. Nesting activity always corresponded with overcast or rainy
days and the author also suggested a correlation of nesting activity to the lunar cycle
(Congello 1978).
Materials and Methods
Study site -The study was conducted at the Rhodes-France Scout Camp (RFSC), in
western Shelby County, Illinois. RFSC is 200 ha of mainly oak-hickory forest, 40 ha of
which are used by the scouts, who have placed some permanent structures and created
various open areas within the forest for campsites. The area is not open to the public and
has minimal human activity except for the months of June, July, and August, when
summer camps are held. Sections of the camp have been periodically logged as recently
as 30 years ago. The camp is bordered on the north and west by agricultural fields (com,
soybean, alfalfa) and on the south and east by a grazed cattle pasture. Because of the size
of the camp and limited manpower, I restricted my searching to the eastern third of the
4
camp, which contained all of RFSC camping sites and was therefore more accessible by
vehicle.
Methods - Beginning in April 2001, I located turtles by walking through RFSC and
searching. For each turtle encountered I recorded sex, mass(± 1 g), carapace length (CL,
± 0.01 mm), plastron length (PL,± 0.01 mm), shell depth (measured at plastral hinge to
top of carapace,± 0.01 mm), any unique features (bum scars, bite marks, old wounds,
etc.), time of day, and location where found. I then filed a set of unique notches into the
marginal scutes of the carapace (each scute being assigned a numeric value) for future
identification. Sex was determined based on eye color, plastron concavity, and relative
tail length and hind limb thickness as described by Cahn (1937). Any female found that
was greater than 120 mm CL had a radio transmitter glued to the right posterior of the
carapace using rubber silicone sealant (Advanced Telemetry Systems model 7PN). I then
released each turtle at its site of capture.
Based on records in the literature (Ernst et al. 1994, Phillips et al. 1999), I
assumed that oviposition would begin anywhere from late May to early June. Therefore,
I chose the first week of May 2001 to relocate all females carrying transmitters and took
them to a veterinarian's office to be radiographed to determine gravidity. I removed the
transmitters from females lacking eggs and released them at their site of relocation. For
gravid females, I recorded clutch size and then attached a thread trailer with rubber
silicone sealant on their carapace on the side opposite the transmitter. The thread trailer
was constructed from a short length of polyvinyl chloride (PVC) pipe with caps at each
end. A small internally wound thread bobbin was placed inside the pipe. A small hole
was drilled in the middle of one of the caps for the thread to pass through. The trailer
5
was glued to the right posterior side of the turtle's shell with the cap free, to allow the cap
to be removed for replacement of the thread bobbin. The total mass of the thread trailer
with bobbin and the transmitter was 4 7 g (about 10% of the average body weight of an
adult female). Studies have shown that turtles can accommodate an attached load of this
magnitude without significant impairment of their locomotion (Zani and Claussen 1995,
Marvin and Lutterschmidt 1997) so it is unlikely that thread trailers altered behavior or
movement. Once the trailer was attached, I again recorded the turtle's mass and then
released her at point of relocation. I also flagged the location and tied the string from the
trailer to the flag.
Turtles were relocated daily. For each relocation, I recorded the position, activity
when found, and mass. Locations were described using visual landmarks and a flag was
placed at the site (it is unlikely the flag attracted predators to the turtle as no instances of
predation on an marked adult turtle were recorded in this study). Latitude and longitude
were later recorded for each relocation site using a global positioning system (GPS) unit
(accuracy of 15 m). Descriptions of activity when found were based on Dodd et al.
( 1994) and were recorded as either walking, feeding, resting while exposed, resting while
buried under cover, or engaging in nesting behaviors (digging, oviposition, covering nest,
etc.). Box turtles generally nest in the evening hours (Allard 1935, Legler 1960, Dodd
2001) so I always located females between 1700 and 2100 h to increase the chance of
locating a turtle while nesting. I also searched both forested and cleared areas for nesting
activity by unmarked females. After 1700 h, a female was either searching for a nest, in
one of the stages of nesting, or in a "form," a shallow depression in the soil or leaf litter
6
in which the turtle spends the night (Stickel 1950). Locating females in the evening
hours made it relatively easy to determine if a female would lay eggs that night.
If a female was active when found, she was observed from a distance (to prevent
her spotting me and potentially abandoning a nesting attempt) every half hour until
nightfall to determine if she was nesting. When possible I continued observing the
female until oviposition was completed. If this was not possible, I marked the nest site
with a coin and returned to the site the next morning. If the female was found in a form, I
checked the thread trailer and then recorded her mass to make sure she had not laid eggs
earlier in the day. Because each egg weighs approximately 10 g, and there are several per
clutch, abrupt weight reductions (> 30 g) would indicate if eggs have been laid (Doroff
and Keith 1990). If a female had laid eggs without my observation of the occurrence, I
followed the path left by the thread trailer to search for the nest. Nesting dates were
recorded and later compared with precipitation data for Pana (approximately 14 km away
from RFSC), Christian County, Illinois received from the Midwest Climate Center.
If the nest was still intact when located, I recorded the number, size, and mass of
the eggs, and then protected the nest from future predation attempts by placing a circular
cage, 30 cm in diameter, of 1.3-cm hardware cloth over the top and down 15 cm into the
soil around the nest (Graham 1997). Relative clutch mass was also determined for each
female with an intact nest.
On 30-31July2001, I quantified the vegetation structure of the sites using
methods similar to those of Wilson (1998). A one-meter square area centered on each
nest site was visually estimated for percentage bare ground, herbaceous plants, woody
plants, and leaf litter. Vegetation height was measured to the nearest centimeter with a
7
ruler and assigned to a category (0-10 cm, 11-20 cm, 20-30 cm, etc.). I also measured
canopy cover using a spherical densiometer, and light intensity(± 1 lux) with a hand-held
light meter. I then recorded the same measurements for 75 random sites. I located
random sites by first making an east and west border on each side of my study area. I
then started at the western side and made a series of parallel lines, spaced 15 m apart, that
extended from west to east. At the starting point of each of these parallel lines, I then
moved eastward across the site, pacing random distances (determined by pulling two
numbers, 0-9, out of a cup) until I had reached the other side, marking each randomly
located site with a flag. The categories from nesting and random sites were then analyzed
using a principle component analysis (Ludwig & Reynolds 1988).
Results
A total of 117 turtles of both sexes were observed in this study. Sixty-three males
and 35 females were found and marked, giving a male: female sex ratio of 1.8:1.0. I also
found eight juveniles(< 120 mm CL) and recorded eight hatchlings from three successful
nestings. Morphometric data for these individuals are reported in Table 1.
Of the 35 female turtles observed, ten had transmitters attached to their carapace
and were radiographed, eight of which were gravid. Clutch size was determined from the
radiographs and ranged from one to seven eggs (mean= 3.88 eggs). However, only four
of these turtles nested. The remaining four females were tracked until September and
then radio graphed again. No eggs were visible in any of these individuals.
I located twenty-four nests, all through direct observation of nesting activity, from
both marked and unmarked females. Most of the females (88%) nested within 24 hours,
8
\0
Table 1. Mean and standard deviation values for carapace length (CL), plastron length (PL), carapace depth (CD), and mass of eastern
box turtles (Terrapene c. carolina) measured at Rhodes-France Boy Scout Camp, Shelby County, Illinois, during Summer 2001.
Sex CL (mm)
Males (n = 63) 139.20 ± 10.59
Females (n = 35) 134.81±13.91
Hatchlings (n = 8) 32.02 ± 0.87
PL(mm)
128.49 ± 7.01
128.14 ± 9.00
29.87 ± 1.79
CD(mm)
65.17 ± 8.34
66.78 ± 4.12
14.06 ± 1.82
Mass (g)
468.95 ± 78.21
468.29 ± 108.01
8.00 ± 0.00
before or after, a precipitation event (y_2 = 4.46, p ~ 0.05; Fig. 1), and laid their eggs in
either open areas (campsites or unpaved roadways) within the camp or in grazed
meadows bordering the camp. Each female from the three intact nests I recorded had a
relative clutch mass of 0 .10 (following Shine and Schwarzkopf 1992). The principle
component analysis applied to the measured habitat variables resulted in 98.8% of the
variance being explained by one component. Nest sites differed from random sites in
percent woody vegetation, bare ground, leaf litter, canopy cover, vegetation height, and
light intensity (Kolmogorov-Smirnov tests, p < 0.02; Table 2). When compared to
random sites, nest sites are characterized as having shorter vegetation, less leaf litter,
more bare ground, less woody vegetation, less canopy cover and higher light intensity
than random sites.
Of the twenty-four nests that were observed, 21 were destroyed by predators
within 72 hours of oviposition, with 85.7% (18 nests) of this predation occurring within
24 hours. The three nests I located intact and protected with hardware cloth from
predators each had hatchlings emerge from them in September.
Discussion
Body size - The morphometric data I collected in this study is typical of T. c. carolina.
Males in this taxa are on average larger and reach greater maximum sizes than females
(Ernst et al. 1994, Dodd 2001 ). The best explanation for this difference is that larger
males have an advantage over smaller males in copulation because the plastron concavity
of larger males allows a better fit against the female's carapace (Dodd 2001 ).
10
I precipitation (mm) • nest events x 100- 6
• x 5
75-
i x 4 ....,
~ 3 ;I 50- x x xx 3 t ·i 1 ·g • a x • 2
25-• x • •
• • 0- ·- - • - .. ... 0 150 155 160 165 170 175 180 185 190 195 200
Julian date
Fig. 1. Occurrence of nesting in eastern box turtles (Terrapene c. carolina) with
precipitation events at Rhodes-France Boy Scout Camp, Shelby County, Illinois in
Summer 2001. Each dot in the figure, even those near the origin, represent precipitation
having occurred.
11
Table 2. Kolmogorov-Smimov test results for features of nest sites (NS; n = 24) and random sites (RS; n = 75) at Rhodes-
France Boy Scout Camp, Shelby County, Illinois, during Summer 2001. Means are reported± 1 SD.
%woody % bare % leaf Light intensity % canopy Vegetation Variable vegetation ground litter (lux) cover height (cm)
Mean (NS) 0.0 ± 0.0 0.39 ± 0.36 0.03 + 0.05 656.7 ± 399.3 0.26 ± 0.39 8.3 ±4.8
Mean (RS) 0.11±0.2 0.15±0.24 0.27 ± 0.29 138.7 ± 216.2 0.71±0.38 37.4 ± 46.3
- Chi square 21.734 9.601 15.501 31.202 19.918 18.670 N
P-value <.0001 .0165 .0009 <.0001 <.0001 .0002
Lack of egg laying by gravid females - Four of the eight females I tracked using radio
transmitters never oviposited. All eight females showed eggs in radiographs taken in
May 2001 and were tracked continuously from May until September. During that time
period I observed no nesting activity and did not observe a weight loss of more than 30 g
in any of these four females, so I must assume that the eggs were laid in increments, less
than three at a time, at different sites. One possibility for its cause is that my nightly
inspections may have stressed the turtles enough to either delay or even prevent
oviposition. Female turtles have been known to abandon nesting activity if they suspect
the presence of a predator (Dodd 2001 ). While I cannot rule out my disturbances as a
cause, the fact that the other four females successfully laid eggs makes this possibility
unlikely.
Nest site selection - All nesting females laid their eggs at sites that differed from random
sites in regard to each variable examined except percent herbaceous cover. All females
placed their nests in open areas within RFSC or within a meadow next to the camp's
boundaries. Previous studies suggest that sunnier areas free of debris may be preferred
by nesting females (Cahn 1937, Legler 1960, Congello 1978, Messinger and Patton
1995). The reasons for this preference are many. For one, although ground temperatures
were not recorded, it is logical to assume that areas with a higher light intensity and less
canopy cover would be warmer than sites with lower light levels and high canopy cover.
Incubation temperature is important because it affects the sex of offspring, developmental
rate, and can possibly influence the fitness of the hatchlings (Burger 1976, Packard et al.
1985, Janzen 1993). Besides providing a higher incubation temperature, bare ground that
is free of debris would also provide an area easy to excavate a nest cavity and may play a
13
role in hatchling survival. Studies with hatchling snapping turtles have shown that the
probability of survival increased with decreasing ground vegetation (Kolbe & Janzen
2001). Survival is probably increased because hatchlings emerging in sparsely vegetated
areas move quicker and more continuously than hatchlings emerging in denser
vegetation. In box turtles, bare areas may encourage hatchlings to disperse quickly into
forested habitat and may aid in their movement by providing fewer obstacles to move
through.
Turtles may use soil temperature, soil moisture, slope, vegetation, or even
predation risk when choosing a nest site (Wilson 1998, Weisrock & Janzen 1999, Wood
& Bjomdal 2000, Kolbe & Janzen 2001, Spencer 2002, Morjan 2003). I believe that the
turtles in this study chose this type of micro habitat because of the higher soil
temperatures. However, because the females in this study all began digging from 1800-
2000 h, it is unknown whether they were using light intensity, lack of canopy cover,
density of vegetation, or were sensing changes in soil temperatures when choosing sites.
No nesting activity was observed in the wooded areas of my study site, even
though I spent approximately twice as much time searching in wooded areas as I did open
areas. It could be argued that nesting females were easier to find in the open areas than in
wooded areas and this explains why none were discovered nesting in the forest.
However, the four females I found nesting with radiotransmitters all chose open areas,
and previous studies suggest that an open canopy is a key element in nest site choice and
that females prefer open areas (Cahn 1937, Legler 1960, Congello 1978, Messinger and
Patton 1995). Also, the amount of tree and shrub roots in wooded areas would appear to
make digging a nest cavity difficult if not impossible. For these reasons, I feel I obtained
14
a fairly accurate sample of nesting activity. This idea could be tested in a future study by
including a larger area of the camp. Because of the relative ease in locating and traveling
to sites with turtles, I concentrated my efforts in an area of RFSC that contained
campsites. By observing females in a part of the camp that did not contain campsites one
could compare nest site choice between the two groups. It is possible that the females in
my study readily used the campsites because they were convenient and that females
without these options are forced to choose less favorable sites or travel farther to reach
more favorable sites (see Appendix I).
Most turtles in this study nested within 24 hours of a rain event. This phenomenon
has been recorded by Congello (1978), who suggested that females may use cloud cover
and rising humidity levels to predict favorable nesting conditions several hours before a
rain event. Nesting around a rain event could be favorable in two ways: the precipitation
would soften the ground and make it easier for a female to excavate a nest cavity, and
rain immediately following nesting could wash away the scent of the female from the
nest site, making nest predation less likely. Some authors have reported observing
females voiding their bladders over the nest site (Conant 1938, Legler 1960) but I neither
observed, nor saw evidence of, this activity at any of the nest sites in this study.
Nest predation- Of the 24 nesting events observed, 21 ended in predation of the nest
(most of these within 24 hours). Almost any digging animal will consume turtle eggs,
and predators include raccoons (Procyon lotor), opossums (Didelphis virginiana),
coyotes (Canis /atrans), mink (Mustela vison), skunks (Mephitis mephitis), and foxes
(Vulpes, Urocyon) (Temple 1987). While I could not positively identify the species of
15
animal that destroyed the nests in my study, it is likely that raccoons were responsible for
the majority of predation. Due to their adaptability and lack of natural predators, raccoon
populations in many areas are at an abnormally high abundance (Garrott et al. 1993).
This same problem exists at RFSC (pers. obs.), which has an extremely high raccoon
population (trapping and removal has been attempted with little success; Theron Tinker,
pers. comm.). The problem of nest predation at this site may even be exacerbated by the
fact that young campers often leave food items strewn about their campsites. The
raccoons are drawn to the campsites in search of food left by campers and can easily
encounter nesting females and eggs. Given this pattern of land use, female box turtles at
RFSC are placing their eggs in areas that are less than ideal for survival.
Conclusions
Female box turtles in this study chose nest sites that differed from random sites in
percent woody vegetation, bare ground, leaf litter, light intensity, canopy cover,
vegetation height, and light intensity. Light intensity and ease of digging in the bare
ground are the most likely factors affecting female choice, but it is not known exactly
how nesting females are detecting or comparing these factors. Females appeared to
prefer to nest either shortly before, during, or immediately following a rain event. The
fact that all the females in this study nested in man-made clearings (campsites, roads, or
meadows) is important for two reasons. First, it indicates that the use of artificial nesting
areas or structures may have a potential use in helping increase turtle numbers for
populations threatened by habitat loss. Conversely, nesting in man-made areas may
actually be producing a negative effect on turtle populations by encouraging females to
16
nest in less than ideal sites. Another issue threatening the turtles in this study is nest
predation, and must be considered if creating a management plan for this species at
RFSC.
Populations of many Terrapene species have been steadily declining in the past
50 years (Stickel 1978, Williams and Parker 1987, Doroff and Keith 1990, Schwartz and
Schwartz 1991, Dodd and Franz 1993, Belzer and Steisslinger 1999), mainly due to
collections for the pet trade and the influences of urbanization and agriculture (Butler and
Sowell 1996). The fact that the annual survivorship of either turtle eggs and hatchlings is
lower than those of later life stages (Iverson 1991) makes understanding these early
stages a vital component in understanding and conserving a species. The use of habitats
for nesting that are different from habitats utilized during other parts of the activity
season also has important conservation implications. If box turtles' home ranges are
protected, but not their nesting sites, the loss of quality nest sites may lead to decreased
egg and hatchling survival (Wilson 1998, Tucker and Paukstis 1999). The division of
home ranges and nesting sites by roads or unsuitable habitat may have the added effect of
increasing the mortality of gravid females as they move between sites (Stickel 1978, Hall
et al. 1999). Increasing fragmentation of turtle habitat may also increase rates of nest
predation (Temple 1987).
Terrapene. c. carolina is still considered a common species in North America, yet
little is known on its status in the wild (Dodd and Franz 1993, Hall et al. 1999). A lack of
basic ecological information on many turtle species, including data on nest site selection,
has hindered efforts to interpret population declines or recommend management-related
research (Landers et al. 1980, Dodd and Franz 1993). It is only by establishing
17
population and life history data on a species while it is still common that wildlife
managers will have the information necessary to initiate conservation actions when
declines become apparent.
18
Bibliography
Allard, H. A. 1935. The natural history of the box turtle. Sci. Monthly 41 :325-338 .
. 1948. The eastern box turtle and its behavior. J. Tennessee Acad. Sci. 23:307----
321.
Belzer, W.R., and M. B. Steisslinger. 1999. The box turtle: Room with a view on
species decline. Amer. Biol. Teacher 61:510-513.
Bissett, D. 1968. Box turtle nesting. Int. Turtle and Tortoise Soc. J. 2:12-16.
Breder, R. B. 1927. Turtle trailing: A new technique for studying the life habits of
certain testudinata. Zoologica 9:231-243.
Brewster, K. N., and C. M. Brewster. 1991. Movement and microhabitat use by juvenile
wood turtles introduced into a riparian habitat. J. Herpetol. 25:379-382.
Burger, J. 1976. Temperature relationships in nests of the northern diamondback
terrapin, Malaclemys terrapin terrapin. Herpetologica 32:412-418.
Burger, J., and W. A. Montevecchi. 1975. Nest site selection in the terrapin Malaclemys
terrapin. Copeia 1975:113-119.
Butler, B. 0., and S. Sowell. 1996. Survivorship and predation ofhatchling and yearling
gopher tortoises, Gopherus polyphemus. J. Herpetol. 30:455-458.
Cagle, K. D., G. C. Packard, K. Miller, and M. J. Packard. 1993. Effects of the
microclimate in natural nests on development of embryonic painted turtles,
Chrysemys picta. Fune. Ecol. 7:653-660.
Cahn, A. R. 1937. The turtles of Illinois. Illinois Biol. Monogr. (35):1-218.
19
Claussen, D. L., M. S. Finkler, and M. M. Smith. 1997. Thread trailing of turtles:
methods for evaluating spatial movements and pathway structure. Can. J. Zool.
75:2120-2128.
Conant, R. 1938. The reptiles of Ohio. Amer. Midl. Nat. 20:1-200.
Congdon, J. D., D. W. Tinkle, G. L. Breitenbach, and R. C. van Loben Sels. 1983.
Nesting ecology and hatchling success in the turtle Emydoidea blandingi.
Herpetologica 39:417-429.
Congdon, J. D., A. E. Dunham, and R. C. van Loben Sels. 1994. Demographics of
common snapping turtles (Chelydra serpentina): Implications for conservation
and management oflong-lived organisms. Amer. Zool. 34:397-408.
Congello, K. 1978. Nesting and egg laying behavior in Terrapene carolina. Proc.
Pennsylvania Acad. Sci. 52:51-56.
Diaz-Paniagua, C., C. Keller, and A. Andreau. 1995. Annual variation of activity and
daily distances moved in adult spur-thighed tortoises, Testudo graeca, in
southwestern Spain. Herpetologica 51 :225-233.
Dodd, C. K., Jr. 2001. North American Box Turtles: A Natural History. University of
Oklahoma Press, Norman, Oklahoma.
Dodd, C. K., Jr., and R. Franz. 1993. The need for status information on common
herpetofaunal species. Herpetol. Rev. 24:47-50.
Dodd, C. K., Jr., R. Franz, and L. L. Smith. 1994. Activity patterns and habitat use of
box turtles (Terrapene carolina bauri) on a Florida island, with recommendations
for management. Chelonian Conservat. Biol. 1:97-106.
20
Doroff, A. M., and L.B. Keith. 1990. Demography and ecology of an ornate box turtle
(Terrapene ornata) population in south-central Wisconsin. Copeia 1990:387-399.
Ernst, C.H., J.E. Lovich, and R. W. Barbour. 1994. Turtles of the United States and
Canada. Smithsonian Institution Press: Washington, D.C.
Ewing, H. E. 1943. Continued fertility in female box turtles following mating. Copeia
1943:112-114.
Garrott, R. A., P. J. White, and C. A. V. White. 1993. Overabundance: An issue for
conservation biologists? Conservat. Biol. 7:946-949.
Graham, T. 1997. Effective predator excluders for turtle nests. Herpetol. Rev. 28:76.
Hailey, A. 1989. How far do animals move? Routine movements in a tortoise. Can. J.
Zool. 67:208-215.
Hall, R. J., P. F. P. Henry, and C. M. Bunck. 1999. Fifty-year trends in a box turtle
population in Maryland. Biol. Conservat. 88:165-172.
Hurlbert, S.H. 1984. Pseudoreplication and the design of ecological field experiments.
Ecological Monographs 54: 187-211.
Iverson, J.B. 1977. Reproduction in freshwater and terrestrial turtles of North Florida.
Herpetologica 33:205-212.
___ . 1990. Nesting and parental care in the mud turtle, Kinosternonflavescens. Can.
J. Zool. 68:230-233.
___ . 1991. Patterns of survivorship in turtles (order Testudines). Can. J. Zool.
69:385-391.
Janzen, F. J. 1993. An experimental analysis of natural selection on body size of
hatchling turtles. Ecology 74:332-341.
21
Keller, C. 1993. Use of fluorscent pigment for tortoise nest location. Herpetol. Rev.
24:140-142.
Kolbe, J. J., and F. J. Janzen. 2001. The influence of propagule size and maternal nest
site selection on survival and behaviour of neonate turtles. Fune. Ecol. 15 :772-
781.
___ . 2002. Impact of nest-site selection on nest success and nest temperature in
natural and disturbed habitats. Ecology 83 :269-281.
Landers, J. L., J. A. Gamer, and W. A. McRae. 1980. Reproduction of gopher tortoises
(Gopherus polyphemus) in southwestern Georgia. Herpetologica 36:353-361.
Legler, J.M. 1960. Natural history of the ornate box turtle, Terrapene ornata ornata
Agassiz. Univ. Kansas Puhl. Mus. Nat. Hist. 11 :527-669.
Ludwig, J. A., and J. F. Reynolds. 1988. Statistical ecology: a primer of methods and
computing. Wiley Press, New York, New York.
Marvin, G. A., and W. I. Lutterschmidt. 1997. Locomotor performance in juvenile and
adult box turtles (Terrapene carolina): A reanalysis for effects of body size and
extrinsic load using a terrestrial species. J. Herpetol. 31 :582-586.
Messinger, M.A., and G. M. Patton. 1995. Five year study of nesting of captive
Terrapene carolina triunguis. Herpetol. Rev. 26:193-195.
Morjan, C. L. 2003. Variation in nesting patterns affecting nest temperatures in two
populations of painted turtles (Chrysemys picta) with temperature-dependent sex
determination. Behav. Ecol. Sociobiol. 53:254-261.
Nieuwolt, P. M. 1996. Movement, activity, and microhabitat selection in the western
box turtle, Terrapene ornata luteola, in New Mexico. Herpetologica 52:487-495.
22
Nieuwolt-Dacanay, P. M. 1997. Reproduction in the western box turtle, Terrapene
ornata luteola. Copeia 1997:819-826.
Packard, G. C., M. J. Packard, and W. H. N. Gutzke. 1985. Influence of hydration of the
environment on eggs and embryos of the terrestrial turtle Terrapene ornata.
Physiol. Zool. 58:564-575.
Phillips, C. A., R. A. Brandon, and E. 0. Moll. 1999. Amphibians and Reptiles of
Illinois. Illinois Natural History Survey Pub. 8: Champaign, Illinois.
Reagan, D. P. 1974. Habitat selection in the three-toed box turtle, Terrapene carolina
triunguis. Copeia 1974:512-527.
Riemer, D. N. 1981. Multiple nesting by a female box turtle (Terrapene c. carolina).
Chelonogica 2:53-55.
Schwartz, C. W., and E. R. Schwartz. 1974. The three-toed box turtle in central
Missouri: Its population, home range and movements. Missouri Dept. Conserv.
Terrestr. Ser. 5:1-28.
Schwartz, E. R., and C. W. Schwartz. 1991. A quarter-century study of survivorship in a
population of three-toed box turtles in Missouri. Copeia 1991 :1120-1123.
Schwarzkopf, L., and R. J. Brooks. 1987. Nest-site selection and offspring sex ratio in
painted turtles, Chrysemys picta. Copeia 1987:53-61.
Shine, R., and L. Schwarzkopf. 1992. The evolution of reproductive effort in lizards
and snakes. Evolution 46:62-75.
Shine, R., and P.S. Harlow. 1996. Maternal manipulation of offspring phenotypes via
nest-site selection in an oviparous lizard. Ecology 77: 1808-1817.
23
Spencer, R.J. 2002. Experimentally testing nest site selection: fitness trade-offs and
predation risk in turtles. Ecology 83:2136-2144.
Stickel, L. F. 1950. Population and home range relationships of the box turtle,
Terrapene c. carolina (Linnaeus). Ecol. Monogr. 20:351-378.
___ . 1978. Changes in a box turtle population during three decades. Copeia
1978:221-225.
___ . 1989. Home range behavior among box turtles (Terrapene c. carolina) of a
bottomland forest in Maryland. J. Herpetol. 23:40-44.
Strang, C. A. 1983. Spatial and temporal activity patterns in two terrestrial turtles. J.
Herpetol. 16:320-322.
Temple, S. A. 1987. Predation on turtle nests increases near ecological edges. Copeia
1987:250-252.
Tinkle, D. W., J. D. Congdon, and Rosen. 1981. Nesting frequency and success:
implications for the demography of painted turtles. Ecology 62:1426-1432.
Tucker, J. K., and G. L. Paukstis. 1999. Post-hatching substrate moisture and
overwintering hatchling turtles. J. Herpetol. 3 3 :608-615.
Walker, T. A., and C. J. Parmenter. 1990. Absence of a pelagic phase in the life cycle of
the flatback turtle, Natator depressa (Gaiman). J. Biogeogr. 17:275-278.
Warner, J. L. 1982. Terrapene c. carolina (Eastern box turtle): Reproduction. Herpetol.
Rev. 13:48-49.
Weisrock, D. W., and F. J. Janzen. 1999. Thermal and fitness-related consequences of
nest location in painted turtles (Chrysemys picta). Fune. Ecol. 13:94-101.
24
Wilhoft, D. C., E. Hotaling, and P. Franks. 1983. Effects of temperature on sex
determination in embryos of the snapping turtle, Chelydra serpentina. J.
Herpetol. 17:38-42.
Williams, E. C., Jr., and W. S. Parker. 1987. A long-term study of a box turtle
(Terrapene carolina) population at Allee Memorial Woods, Indiana, with
emphasis on survivorship. Herpetologica 43:328-335.
Wilson, D. S. 1998. Nest-site selection: Microhabitat variation and its effects on the
survival of turtle embryos. Ecology 79: 1884-1892.
Wood, D. W., and K. A. Bjorndal. 2000. Relation of temperature, moisture, salinity, and
slope to nest site selection in loggerhead sea turtles. Copeia 2000: 119-128.
Zani, P. A., and Claussen, D. L. 1995. Effects of extrinsic load on locomotion in painted
turtles (Chrysemys picta). Copeia 1995:735-738.
25
APPENDIX I
26
Daily Movement and Activity of Gravid Female Box Turtles in Central Illinois
Abstract
I examined the daily movements of 5 female eastern box turtles, Terrapene c.
carolina. Turtles were fitted with a radiotransmitter and thread trailer and were relocated
daily. Using thread trailers I measured daily movements and compared distances moved
to daily temperature, rainfall, and relative humidity. In contrast to previous studies, I
found no correlation between daily movements and any of these meteorological factors.
These findings may be due to the small sample size in this study, or the condition of the
females being followed.
Introduction
Box turtles are, with rare exception (Dodd 2001), diurnal or crepuscular. As
ectothermic animals, box turtles are influenced by exogeneous factors that may affect
their movements. Studies have found that box turtles have periods of activity and
inactivity throughout the day, and these may depend on season (i.e., feeding and
reproduction [Dodd 2001]), temperature (Legler 1960, Nieuwolt 1996, Schwartz and
Schwartz 1974), rainfall (Stickel 1950), and relative humidity (Reagan 1974, Stickel
1950). Turtles are most active when warm temperatures (20°-30°C), high humidity (60%
+),and frequent rainfall occur (Stickel 1950, Strang, 1983, Dodd 2001). When studying
an animal's daily activities and movements, knowing its specific path taken provides
information on types of habitat utilized by the animal, the effect of habitat structure or
landscape features on an animal's movements, distance traveled per day, seasonal
27
changes in movement patterns, and the effect of meteorological conditions on movements
(Claussen et al. 1997).
There are at least three ways in which an animal's movements can be studied:
mark-recapture, radio telemetry, and thread trailing. Mark and recapture provides the
cheapest, least labor intensive approach but recapture rates can be low and the interval
between captures is often unpredictable (Claussen et al. 1997). This technique also gives
no information about the path taken between successive capture points. Radiotelemetry
is a high-cost method that can provide many more location points and is useful in
providing information on long-term habitat use and movements but again, it cannot show
the exact pathway the animal took between relocation points. Thread trailing is a more
time consuming method to track animals but, with the exception of extremely
sophisticated satellite-tracking devices that continuously monitor an animal's position, is
the best option to obtain information about the specific path an animal takes.
The turtle's hard carapace makes them excellent subjects for the attachment of
thread trailers and many studies have used this method (Breder 1927, Legler 1960,
Schwartz and Schwartz 1974, Hailey 1989, Diaz-Paniague et al. 1995, Claussen et al.
1997). Studies have shown that turtles can accommodate an attached load without
significant impairment of their locomotion (Zani and Claussen 1995, Marvin and
Lutterschmidt 1997) so it is unlikely that thread trailers alter behavior or movement.
While turtles may take a seemingly direct path when moving to a specific
location, thread-trailing studies have shown that box turtles often leave meandering trails
that tum, move around objects like trees, and often repeatedly cross their own paths and
those of other turtles (Dodd 2001, Stickel 1950). The distance measured between two
28
capture points may be considerably shorter than the actual distance traveled by the turtle.
For example, Stickel (1950) found that a box turtle in Maryland traveled 139 min one
day but was only 52 m from its last point of capture. When examining the effects of
environmental factors on daily distance moved, it is essential that the actual distance
moved is recorded. Knowing the actual distance moved and the path taken by a turtle
reveals valuable information, especially when developing a conservation management
plan, on how much area and what types of habitat the animal is actually using. For
instance, comparisons of paths and movements between differing box turtle populations
might provide insights into the possible effects of human disturbance on the species. In
this study I sought answers to the following questions: 1) How far does a box turtle
move in a day? 2) Is distance traveled have any relationship to temperature, rainfall,
and/or relative humidity?
Materials and Methods
The data in this study were collected at the Rhodes France Scout Camp (RFSC)
located in western Shelby County, Illinois, from gravid female T c. carolina that were
being tracked with both radio transmitters and thread trailers for the purpose of locating
nest sites (see above for descriptions of the trailers and methods). Thread trailers were
used from 16Juneto31 July2001(Juliandays165-215). Irelocatedturtlesdailyand
recorded mass, activity when found, and location where found (location was recorded by
using visual landmarks and later recorded in latitude and longitude using a global
positioning system [GPS]). I recorded the path taken by following the thread trail that
had been laid out by the turtle from that day's movements, and then collected the thread
29
and measured it to the nearest centimeter. In this study, I was more interested in total
distance moved then the exact path taken so I did not measure each tum the turtle had
taken, only the total distance. In the event that a turtle would run out her trailer in a 24
hour period, I would record the data as> 175 m moved, which was the total length of
thread in the trailer. Daily measurements were then compared to weather data for Pana
(approximately 14 km from RFSC), Illinois, compiled by the Midwest Climate Center.
Mean values of all five turtles were analyzed using simple regression for mean daily
temperature, daily rainfall, and mean relative humidity.
Results
Daily movement for each turtle varied considerably, from no movement to
movements greater than 175 m, with an average of 64.14 m moved each day. One turtle
was completely inactive for ten days while another turtle moved every day of the study.
Paths were often meandering, circling around trees and crossing each other repeatedly,
with the turtle usually ending her day a short distance from where she had started.
Simple regressions showed no relationship between daily distance moved and daily
temperature (r2 = 0.01, p = 0.61, n = 40) or relative minimum (r2 = 0.02, p = 0.37, n = 39)
and maximum (r2 = 0.01, p = 0.59, n = 39) humidity. A one-way ANOVA did not detect
any relationship between daily distance moved and whether or not it rained that day (F1,Js
= 0.75, p = 0.39).
Discussion
Many people view turtles as slow-moving creatures that lead relatively inactive
30
lives. However, turtles engage in a variety of behaviors and activities in their daily and
seasonal lives. As in other studies (Dodd 2001, Stickel 1950), the turtles in this study
exhibited meandering movements, with a path often circling around objects (one female
continually circled and passed through a camper's tent and around the legs of a cot) and
crossing and recrossing itself. Distance between relocation points could not provide a
true account of the daily distance moved as a turtle was often relocated a short distance
from her last location. One reason for this it that all of the females in this study had a
tendency to have 3 or 4 locations that they used for sleeping, known as forms, and were
repeatedly found at these locations when I checked them in the evening, even though they
had moved a considerable distance away from the form during the day. As an example,
one female moved 67.25 m in one day but was found only 2 m from her last location.
Despite their tendency to meander, occasionally a turtle would lead a very straight
path, often for a considerable distance. Many times a turtle would follow a dry creek bed
or animal path, but other times the turtle would create her own trail through a mix of
vegetation and straight over any obstacles (i.e., fallen trees) in the way. The length of
these straight line paths could be as short as 6 m but were often longer and on 5 occasions
turtles were located 500 m (straight line distance) or more from their previous location.
In these instances, the turtle would always stay in the area for only one or two days and
then the thread trail would show another straight path back to where she had been found
on previous locations. For example, one female that I had located in one of her forms the
previous night was found in the late afternoon of the next day 512 m (the trailer laid a
straight path for 175 m, I then measured a straight line distance from the end of the trailer
to the turtle) away under a multiflora rose (Rosa sp.) in a cow pasture bordering the
31
camp. She was located there the following day but on the third day had made another
straight line path (following almost exactly her previous path) back to the form used on
the first day. My first thought upon encountering her in the pasture was that she had
moved to this location to nest, but no nesting activity was observed and no drop in mass
was recorded (indication eggs had been laid). This behavior has also been observed in a
population of three-toed box turtles (T. c. triunguis) in Texas (J. Koukel, pers. comm.).
While I observed only females, Koukel found that only male turtles would move these
large, straight line distances. The reason for these movements is unknown: previous
studies have shown that female box turtles may move long distances in order to reach a
suitable nesting site (Stickel 1950, Legler 1960). Another hypothesis is that the turtle is
following some olfactory cue (i.e., food source, member of the opposite sex, etc.).
Further study of these movements is important as it may cause a re-evaluation of a
turtle's habitat requirements and home range size.
Unlike previous studies (Stickel 1950, Claussen et al. 1997, Dodd 2001), my
turtles showed no correlation between daily distance moved and daily mean temperature,
occurrence of rainfall, or daily mean relative humidity. These results should be
interpreted with caution, however, as analyses are based on a pseudoreplicated data set
(Hurlbert 1984). Also, my sample size was small and I was recording data from only
gravid females. It is possible that their behavior may have been modified by their
condition and therefore affected the results, (i.e., the demands of egg production and the
motivation to find a nest site for oviposition may have been a larger determinant of
distance moved than meteorological factors). In a study of ornate box turtles (T. ornata),
Legler (1960) found that gravid females had the greatest daily mean distance moved
32
(110.6) as compared to males (88.1) and non-gravid females (68.9). A larger sample size
including males and both gravid and non-gravid females would be required to gain a
better understanding of what factors influence daily movements and activities at RFSC.
Conclusions
Female box turtles at RFSC showed no correlation between daily distance moved
and either daily mean temperature, occurrence of rainfall, or daily mean relative
humidity. These results could be explained either by the small sample size or the fact
that gravid turtles may behave differently than non-gravid or male turtles. Their daily
movements showed meandering paths that covered little straight line distance and ended
in often-utilized resting locations, or forms.
An interesting aspect of this study was the occurrence of lengthy straight line
movements by three of the females to a particular spot and then the direct movement
back to their previous locations a few days later. I believe that investigating the reasons
(i.e., nesting, hibernation, mating, finding a food source, etc.) behind these movements in
the turtle warrants further study for many reasons. If one discounts, or is unaware of,
these long distance movements, the amount of habitat needed by a turtle could be
drastically underestimated. If it is necessary for some turtles to move long distances to
nest, it may shed light on the inappropriateness of captive nest site selection studies.
And, with the ever increasing amount of habitat loss and fragmentation occurring in our
environment, understanding these long distance movements may have important
conservation implications as well.
33
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