March 22-23, 2013- North Carolina Zoological
Park, Asheboro, NC
Table of contents:
1) Resting Metabolism of Eastern Box
Turtles (Terrapene carolina)
2) Photography as a Means of Identification of
Individual Eastern Box Turtles, Terrapene carolina
carolina
3) Parentage in the Eastern Box Turtle
Terrapene c. carolina
4) Baseline
Hematology and Plasma Biochemistry Values for Free-Ranging Eastern Box Turtles
(Terrapene carolina carolina) in Illinois and Tennessee
5) Artificial Nest Experiments on Methods to Reduce
Predation on Ornate Box Turtle Nests
6) Helping Box Turtles by Educating the
Public
7) Road Mortality in Terrapene carolina
and T. ornata: Are Females More at Risk?
8) Effect of Prescribed Fire on Overwintering
Terrapene carolina
9) Young Citizen Scientists Tracking Box Turtles at
the Lake Raleigh Area
10) Use of
Automated Radio Telemetry to Detect Nesting Activity in Ornate Box Turtles,
Terrapene ornata
11) Patterns of Morphological Variation in the
Shell of the Eastern Box Turtle (Terrapene carolina)
12) Likelihood of Turtle Mortality During
Attempted Road Crossing
13) Risk and Response of Box Turtles to
Prescribed Fire
______________________________________________________
1) Resting Metabolism of Eastern Box Turtles
(Terrapene carolina)
Eva Grebe1
and C. M. Gienger
Center of Excellence for Field Biology at Austin
Peay State University, Clarksville, TN
Measuring the Standard Metabolic Rates (SMR) of
ectotherms is key to understanding their thermal physiology and understanding
the potential impacts of an altered global climate. We measured SMR of box
turtles from a population in Tennessee (USA) and determine how variation in body
size and temperature influence patterns of resting energy use. Our results
indicate that across both juvenile and adult body sizes, individuals tested at
30C have approximately double the SMR as individuals tested at 20C. There is
also no indication that a difference exists in male versus female SMR at the two
temperatures. This information will also aid in assessing potential effects of
global climate change on alterations of energy budgets of free-ranging box
turtles.
2) Photography as a Means of Identification of
Individual Eastern Box Turtles, Terrapene carolina
carolina
Donald E. Hoss1, Carolyn R. Hoss1 and Antoinette M. Gorgone2,3
1Beaufort, NC
2Southeast Fisheries Science Center, National
Marine Fisheries Service, National Oceanic and Atmospheric Administration,
Beaufort Lab, Beaufort, NC
Photographic techniques to identify individuals from
their natural markings have been well established for many species, including
turtles. The ability to identify individuals over long periods can be used for
mark-recapture techniques which can provide information on movement,
distribution and population size. Our objective was to determine if the patterns
on the carapace of individual Eastern Box Turtles (Terrapene carolina
carolina) could be a method to identify individuals and if this method could
be used over period of years. Box turtles were captured opportunistically over a
12 year period on a 3.4 ha mostly wooded site in the eastern portion of Carteret
County, North Carolina. All turtles were photographed, measured and weighed.
During the study period, we captured and photographed 40 turtles that ranged
from 2.8 to 15.2 cm straight plastron length. Sixteen turtles were captured more
than once. The longest period between capture and subsequent recapture was nine
years. The smallest turtles captured (less than 7 cm in plastron length) had not
developed the adult markings on the carapace. Turtles greater than 7 cm in
plastron length, at time of capture, had developed the adult pattern and showed
no change in shell pattern when recaptured. This method of “marking” turtles may
be a valuable tool for citizen scientist projects in that it is inexpensive,
easy to accomplish and is non-invasive to the turtle. We conclude that
photography can be used as a non-invasive method for identifying individual
eastern box turtles.
3) Parentage in the Eastern Box Turtle
Terrapene c. carolina
Steven J.A. Kimble1, Russell L. Burke, Tim Green, and Rod N.
Williams
Department of Forestry and Natural Resources,
Purdue University, West Lafayette, IN
Multiple census studies of the eastern box turtle
(Terrapene c. carolina) demonstrate that this species is experiencing
steep population declines. Understanding basic biology of a declining species is
an indispensible first step in reversing these trends. While much of the natural
history of box turtles in known, key aspects remain poorly understood, leaving
management plans incomplete. These include traits that can be best assessed at
the genetic level, such as the mating system. Reproductive strategies such as
multiple paternity drive up reproductive variance. High reproductive variance
reduces the effective size of a population because it indicates that the actual
number of parents contributing to the next generation is much reduced.
Specifically, it means that every individual found in a census may not reproduce
successfully in a given year, and management plans must allow for this
phenomenon. High reproductive variance, therefore, can compound demographic
declines, a phenomenon that must be incorporated into management plans for any
such species. Multiple paternity is likely in box turtles as it has been
documented in several confamilial species (e.g., Glyptemys insculpta,
Emys blandingii, Emys orbicularis, Chrysemys picta) but
frequency can vary greatly among closely related species and even among
populations. This study will help parameterize effective population size
estimates, inform captive rearing efforts, and develop hypotheses about the
social mating system in box turtles.
4) Baseline Hematology and Plasma Biochemistry
Values for Free-Ranging Eastern Box Turtles (Terrapene carolina carolina)
in Illinois and Tennessee
Terrell C. Lloyd,1,6, Matthew C. Allender2, Michael J. Dreslik3, John Byrd4, Christopher A. Phillips3, and Russell Moore5
1College of Veterinary Medicine, University of
Illinois, Chicago, IL
2Department of Comparative Biosciences, University
of Illinois, Urbana, IL
3Illinois Natural History Survey, Prairie Research
Institute, University of Illinois, Champaign, IL
4Clinch River Environmental Studies Organization
(CRESO), Clinton, TN
5Dept. of Pathobiology, University of Illinois,
Urbana, Il
Few studies have established sufficient hematologic
and plasma biochemical analysis of free-ranging Eastern box turtles
(Terrapene carolina carolina). Thus, a comparative health
assessment was employed to 1) establish a baseline health assessment for two
populations and 2) provide a comparative health assessment between those
populations. Physical examinations were performed and blood samples were
collected from 426 Eastern box turtles in east central Illinois and Oak Ridge,
Tennessee. Individuals were sampled during three separate time periods: May
(spring), late June (summer), and September (fall) of 2011 and 2012. Several
comparisons were made including changes in health parameters based on age, sex,
institution, and season. Reference ranges were established for packed cell
volume, total solids, white blood cell and differential counts, calcium,
phosphorus, aspartate aminotransferase, bile acids, creatine kinase, and uric
acid. The results provide a baseline health assessment via clinical parameters
for both the Tennessee and Illinois populations. These results can be used as
baseline clinical parameters and serve as an indicator of population health in
future studies. Protocols established for this project can be adapted and
included for other box turtle biological surveys.
5) Artificial Nest Experiments on Methods to Reduce
Predation on Ornate Box Turtle Nests
Andrew McCollum1,4, Neil Bernstein2, Bob Black1,3
1Department of Biology, Cornell College, Mount
Vernon, IA
2Department of Natural and Applied Sciences, Mount
Mercy University, Cedar Rapids, IA
3Deceased
The ornate box turtle, Terrapene ornata, is
listed as threatened in Iowa, as it is in much of the Midwest. While it is
possible to identify a number of threats to the species in the state, the
greatest source of mortality in the life history of this species is nest
predation, closely followed by predation on hatchlings and young juveniles.
While this is common in turtle life histories, is it likely that predation rates
are artificially high in the modern agricultural-residential matrix of land use
in which populations of omnivorous predators are subsidized by agricultural
crops and human refuse. One goal of our research is to investigate practical
methods to reduce nest predation. While protecting nests with cages is
effective, it requires locating nests, which is labor intensive. Cages are also
highly visible to humans and may increase human disturbance or poaching. We
conducted three experiments using artificial nests to assess (1) the cues nest
predators use to identify nests, (2) the efficacy of a hot-pepper powder
(“Squirrel Away”) as a predator repellent, and (3) the efficacy of adding
increasing numbers of unprofitable (empty) nests into an experimental array as a
means of reducing detection and depredation of profitable (chicken egg-bearing)
nests. Artificial nests were depredated at equal rates regardless of distance
from an ecological edge, the presence of a marking flag or the presence of eggs
in a nest; from these observations we conclude that disturbed soil is the
primary cue used by nest predators to detect potential nests. Artificial nests
treated with hot pepper powder were no less likely to be depredated, so we
conclude that that approach seems unlikely to provide any protection to nests.
Finally, increasing the number of unprofitable nests in an experimental array
had no effect on the risk of predation on nests containing chicken eggs; in
fact, the overall rate of nest excavation by predators was greatest in arrays
with the greatest number of empty nests. This latter result may be an artifact
of the fixed size of our arrays, such that increasing the number of empty nests
increased nest density in the array and reduced the average distance between
nests. Our presence at one site, where we had crews of 2-3 people working daily
from approximately midnight until noon appears to have had a small but
significant effect on predation, as that site had a lower rate of predation than
the other two sites at which we set up experimental arrays but only visited
briefly in daytime to monitor experiments. While we have not to date developed
an effective alternative to cages for reducing nest predation, we remain
optimistic that better understanding of predator behavior may yield practical
solutions.
6) Helping Box Turtles by Educating the
Public
Andrew Mellon
Carolina Box Turtles, Lawndale, NC
Citizen scientists, amateur herpers, and volunteer
educators provide a valuable service to scientists by being able to access
geographic areas and demographics that may be unavailable to the scientific
community for a variety of reasons. Since 2012, I have been collecting box
turtle data as a citizen scientist and amateur herper for the Davidson College's
Carolina Herp Atlas. This data includes location, sex, physical characteristics,
ambient temperature at the time the turtle is found, and any human activity in
the vicinity. These research findings contribute not only to the Herp Atlas but
to my work as a volunteer educator in informing the public about the decline of
the box turtle in the Western Piedmont of North Carolina. I lecture and create
educational materials for children and adults about the care and husbandry of
box turtles, the dangers of the pet trade to wild box turtle populations, and
easy ways to promote the conservation of box turtles in their natural habitat.
In return, I often learn about new locations to collect information on these
animals.
7) Road Mortality in Terrapene carolina
and T. ornata: Are Females More at Risk?
Ariel Richter1,3, Eric Johansen2, Tom O'Connell1, and Stanley F. Fox2.
1Natural Resource and Ecology Department, Oklahoma
State University, Stillwater, OK
2Zoology Department, Oklahoma State University,
Stillwater, OK.
Many turtle species make periodic and extended
overland migrations, which can result in individuals being struck and killed by
motor vehicles as the turtles cross roads. While both sexes regularly migrate,
females may be more susceptible to collisions because they tend to move farther
than males and may seek out roadside ditches for nesting. Box turtles
especially make extensive overland movements and are often found dead on
roads. Human development is a major influence on turtle mortality because
it reduces the amount of suitable habitat overall and the number of safe
passages for migrating turtles. We predicted that areas with higher road
densities and human development would have a decreased turtle population and
would have higher road mortality. We predicted that both areas would have a
capture and roadkill bias towards females. We surveyed two road routes in the
Sequoyah National Wildlife Refuge (SNWR) in Sequoyah County, Oklahoma (19.4
total miles, forested and agricultural land), and two road routes in the
Norman/Noble city areas in Cleveland County, Oklahoma (41.6 total miles, urban,
suburban, and agricultural development). Each route was driven twice daily
(before 0800 and after 17:00 hrs CDT) for a total of 17 days for the
Norman/Noble routes during 20 May–13 August, 2011, and a total of 25 days for
the SNWR routes during 16 May–13 July, 2011. Surveys included both dead and live
turtles found within 2 meters of the roadway. We pooled data for both
Terrapene species. Road mortality was biased toward females (M=11, F=32).
We also found 9 juveniles, 1 hatchling, and 1 adult of unknown sex. We kept note
of all turtle species encountered for a total of 50 individuals of 6 species
(M=11, F=15, unknown sex=3, juveniles=6, and hatchlings=15). Turtle density was
different and significantly higher at SNWR (mean = 0.078 turtles/mi) compared to
the Norman/Noble locality (mean = 0.023 turtles/mi). We found a significantly
greater proportion of the turtles at the Norman/Noble locality were found dead
on the road (0.69) than at the SNWR (0.08), suggesting that the population at
the more human-developed locality is strongly influenced by road mortality. Box
turtles disproportionately selected areas around large bodies of water and
expanses of herbaceous vegetation. We conclude that roads negatively impact box
turtle populations directly by vehicular mortality and indirectly by leading
towards a male bias in the population, both factors that may greatly impact
recruitment rates for future generations.
8) Effect of Prescribed Fire on Overwintering
Terrapene carolina
Jordan A. Smink1, Kristoffer Wild, and John H. Roe
Department of Biology, University of North
Carolina at Pembroke, Pembroke, NC
There is a keen interest in maintaining and
increasing the population of the only terrestrial turtle species found in North
Carolina, the Eastern Box Turtle, Terrapene c. carolina. These
turtles are slow to mature and have a low reproductive rate, making
them especially susceptible to population decline as a direct or indirect result
of human activities. Prescribed fire is a common management practice employed in
much of the range of T. c. carolina in the southeastern United States. To
develop effective conservation strategies it is important to understand the
behavioral responses of these turtle to fire. In particular, we are studying the
effects of prescribed fire on overwintering microhabitat selection in T. c.
carolina in the North Carolina Sandhills. As turtles may be especially
vulnerable to fire at this critical time of year when their movement responses
are severely impaired, we expect them to associate with habitat features that
confer some protection against fire. We located the overwintering sites of
turtles using radio telemetry in the Weymouth Woods Nature Preserve, where
controlled fire is used to manage the understory of the Long Leaf Pine forest,
and in the Lumber River State Park, where fire is not used. Turtles at both
sites reduced activity throughout October and November, and finally settled into
overwintering sites by early December. Turtles at both sites moved into lowland
habitats near water for overwintering. We are now in the process of collecting
microhabitat environmental variables. Understanding how fire impacts the
availability and distribution of suitable overwintering habitat of T. c.
carolina will yield insight into the effects of fire on this non-target
species, and thus help improve management for this species of conservation
concern.
9) Young Citizen Scientists Tracking Box Turtles at
the Lake Raleigh Area
Juliana Thomas
Exploris Middle School, Raleigh, NC, and
Centennial Campus Center for Wildlife Education in the North Carolina Wildlife
Resources Commission, Raleigh, NC
Exploris Middle School sixth graders have been
collaborating with the Centennial Campus Center for Wildlife Education since
2007 to learn more about Eastern box turtles and the habitats in which they
live. Our study site is Lake Raleigh Woods and some of the surrounding wooded
area not protected from development on North Carolina State University’s
Centennial Campus in Raleigh, NC. Students have used radio telemetry equipment
to track box turtles. With guidance from our educators they collect real data,
learn about the scientific method, and receive hands-on experience with GPS,
temperature guns, sling psychrometers, soil and light testers, Kestrel units,
and GIS. Students develop their own study objectives, carry out all the field
work, plot the data points, analyze the data, write conclusions and develop
questions for continued study. Students also learn about the challenges facing
urban populations of wildlife, relocated turtle complications, and discuss ways
to prevent continued turtle fatalities. They have contributed to news stories,
newspaper articles, given presentations at NCGIS conferences and to our state
government GIS committee, and presented posters of their work with the
turtles.
10) Use of Automated Radio Telemetry to Detect
Nesting Activity in Ornate Box Turtles, Terrapene ornata
Charles R. Tucker1,7, Thomas A. Radzio2, Jeramie T. Strickland3, Ed Britton4, David K. Delaney5 and Day B. Ligon6
1Department of Biology, Missouri State University,
Springfield, MO
2Department of Biology, Drexel University,
Philadelphia, PA
3US Fish and Wildlife Service, Thomson,
IL
4Upper Mississippi River National Wildlife and
Fish Refuge,
IL
5US Army Construction and Engineering Research
Laboratory, Terre Haute, IN
6Department of Biology, Missouri State University,
Springfield, MO
Researchers often employ radio telemetry to
efficiently locate study animals, but the time required to locate individuals
can make monitoring large populations difficult and costly. In 2010–2011, we
located nesting ornate box turtles (Terrapene ornata) in a large group of
radio-tagged animals. To minimize search efforts, we investigated whether
automated radio telemetry and the signal change method could be used to identify
nesting activity before locating animals. The signal change method relies on the
principle that any movement of a radio transmitter, including minor changes in
orientation, can strongly affect the intensity of the transmitter’s signal at a
stationary receiving station. Using video recordings of free-ranging
radio-tagged turtles, we confirmed that transmitter signal strength values can
be analyzed to identify periods of box turtle activity. Early in the 2010
nesting season, automated telemetry observations indicated that some females
engaged in nocturnal activity. Previous reports indicate that ornate box turtles
often nest at night, but are otherwise inactive after dark. Based upon this
information and relatively little indication of nocturnal activity by males, we
hypothesized that nocturnal activity corresponded to nesting. We subsequently
monitored female nighttime activity in near real time, hand-tracked 4
night-active individuals, and found 3 of these turtles nesting. In 2011, we
again selectively hand-tracked night-active females and located nests for 12 of
18 study animals, which approximates the expected annual reproductive rate for
our population. We demonstrate that the signal change method can be used to
identify nesting activity in ornate box turtles and suggest this method may be
of use in other species that nest outside of their normal activity
periods.
11) Patterns of Morphological Variation in the
Shell of the Eastern Box Turtle (Terrapene carolina)
Natasha S. Vitek
Jackson School of Geosciences, The University of
Texas at Austin, Austin, TX
An accurate understanding of subspecific structure
and variation within the Eastern Box Turtle (Terrapene carolina) can
inform conservation efforts, highlighting unique populations or regions that may
deserve particular focus. Terrapene carolina was traditionally divided
into four extant and one extinct subspecies. The high level of intraspecific
variation within the species was assumed to be a reflection of subspecific
diversity. However, research based on genetic data has recovered conflicting
relationships between some subspecies and no support for others. In addition,
researchers studying the largest subspecies have questioned whether supposedly
diagnostic features for those groups may simply be features of large-bodied box
turtles in general. In order to investigate potential morphological support for
the traditionally recognized subspecies, I used geometric morphometrics with two
datasets to investigate to what extent size and subspecific identity can explain
variation in shell shape. One dataset contained 136 specimens ranging from
hatchlings to adults. A second dataset consisted of 200 adult specimens equally
distributed across the four extant subspecies recognized in the United States.
Specimens in both datasets were compared qualitatively and quantitatively
through multiple analyses. Regardless of whether the dataset included or
excluded juveniles, size explained a significant component of shape variation.
In both datasets, larger turtles were more elongated anteroposteriorly, more
bell-shaped dorsoventrally, and had more distinctive marginals in comparison to
smaller turtles. The extent to which subspecific identity explained patterns of
shape variation was more difficult to assess. Statistical comparisons of mean
shape resulted in significant differences between all four nominative
subspecies. I found minor differences in a qualitative comparison of average
shell shape for each subspecies. In contrast, I found that all of the shell
shape of each subspecies was not distinct in morphospace in canonical variates
analyses. Additionally, multiple assignments tests based on shell shape could
not reliably assign specimens to subspecies. It is possible that those
differences between the shell shape of the four nominative subspecies of T.
carolina may be significant statistically, but not significant biologically.
The results of this study should not be interpreted as an argument against
existing subspecific taxonomy of T. carolina. Rather, the results
highlight the need for a better understanding of what explains variation, both
genetic and phenotypic, within the species and how best to conserve the
resulting diversity.
12) Likelihood of Turtle Mortality During
Attempted Road Crossing
Nathaniel S. Weaver1 and Robert Baldwin
Wildlife and Fisheries Biology, Clemson
University, Clemson, SC
Box turtles and other species of turtle crossing the
road are a common sight in the southeastern United States, especially during
breeding season (May-June) (Cureton and Deaton 2012). This puts the animals in
direct danger from motor vehicle strikes. Understanding the reasons for these
strikes and where collisions are most common could prove useful in developing
appropriate strategies to reduce loss. I hypothesize that more turtles are hit
during low light periods (early morning and evening) by accident, and that
deliberate impact is higher in the daytime when turtles are more visible. I also
hypothesize that impact is more likely in urban areas due to the higher number
of cars, but the ratio of the number of impacts to the number of cars passing is
lower for the urban areas. This could occur because fewer people will hit
turtles on purpose on urban roads, possibly for fear of being seen. This could
also occur because drivers are more likely to see a car ahead of them dodging
something in the road and prepare to dodge it themselves on urban
roads.
In a pilot study, a rubber toy turtle approximating
the size and shape of a real box turtle was placed in the road in an urban
setting. In the first hour, 7 out of 267 passing vehicles (2.6 %) swerved and
hit the artificial turtle. In subsequent trials, the decoy was struck 2.7% in
urban areas (n= 713) and 7.2% in rural areas (n= 153).
These findings can be part of a greater conservation
strategy for turtles crossing roads in the southeastern United States. They can
identify the most dangerous time of day and location (urban vs. rural) for a
turtle crossing the road. They can also determine whether vehicle-caused turtle
mortality in this area is high enough to be of concern to long-term population
survival. This information can be distributed to the public, especially in areas
known to have high turtle density.
I am using Twitter and Facebook to collect turtle
sightings on roads in Pickens County, SC where Clemson is located. I collect GPS
coordinates or a description of the location. I will compile this information
into GIS and determine turtle crossing hotspots in Pickens County. This will
help determine where to focus management efforts.
Cureton, J. C. and Deaton, D. R. 2012. Hot Moments
and Hot Spots: Identifying Factors Explaining Temporal and Spatial Variation in
Turtle Road Mortality. Journal of Wildlife Management 76: 1047-1052.
13) Risk and Response of Box Turtles to
Prescribed Fire
Kristoffer Wild1, and John H. Roe
Department of Biology, University of North
Carolina at Pembroke, Pembroke, NC
Prescribed fire is a common management technique
used to maintain the characteristics indicative to longleaf pine communities,
but the effects on non-target species are not well understood. The Eastern Box
Turtle, Terrapenecarolina,is commonly found in longleaf systems, but its
limited mobility and terrestrial tendencies put it at heightened risk of
exposure to fire. Understanding the response of this non-target species to
prescribed fire can assist park mangers in planning more effective management
activities. Using radiotelemetry, we are examining the behavioral response of
T.carolinafire management at Weymouth Woods Sandhills Nature Preserve,
where prescribed fire has been used for decades, as well as at the Lumber River
State Park, where fire is not used. Turtles at both study sites have selected
areas that are in close proximity to watercourses, with several individuals
spending extended periods in water. Turtles are primarily associating with
non-burned areas of the park, including bottomland and upland mixed hardwood
forests, though several areas of intensive activity occur in the longleaf burn
units. We suggest that turtles are selecting habitats that confer some
protection against fire, though they regularly make forays into burn management
units and are then at risk of injury or death from fire. Indeed, one turtle has
been burned and sustained injuries that we suspect contributed to its later
death. Though still preliminary, our study highlights areas and habitats of
intense turtle use that can help park managers assess the risks of prescribed
fire to T. carolina, and ultimately lead to more effective management of
this species of management concern.
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