Leigh Anne Harden's Webpage

Leigh Anne Harden

Davidson College

Class of 2007

Hatching Loggerhead

I am a senior biology major and have been involved with the Davidson College Herpetology Lab since spring of my sophomore year. I began last year by aiding our research coordinator, Steve Price, and other herp lab members in the trapping, measuring, and collecting of stream salamanders for a three-year landscape-scale study. This experiment is designed to explore the effects of urbanization on stream salamander populations in the greater Charlotte area. I will continue to help with this study for the next two spring seasons.

I also help to run the drift fence on the Davidson College Ecological Preserve, assist in various students’ projects when help is needed, and participate in educational outreach programs (i.e. Reptile Day and Ada Jenkins).

Semi-Aquatic Turtle Research

In April of 2006 I began a semi-aquatic turtle study with Nick DiLuzio, junior member of the herp lab. This study was actually the second of a three-year mark-recapture study initiated by Betsy Failey and Clint McCoy in the summer of 2005. Last summer Nick and I used aquatic trapping to examine implications of turtle detectability on pond occupancy of several farm and golf course ponds. After trapping a surprising number of eastern mud turtles at a local golf course pond, I became interested in this species' terrestrial activity and habitat use and intiated a long-term radiotelemetry study soon after. I will be continuing the third and final turtle trapping session this summer at the same farm and golf course ponds.

Terrestrial activity of eastern mud turtles (Kinosternon subrubrum) on golf courses: an investigation of habitat selection

Harden, Leigh Anne, Steven J. Price, and Michael E. Dorcas

In urbanized landscapes, golf course ponds may provide the only remaining suitable habitat for semi-aquatic turtles. Eastern mud turtles (Kinosternon subrubrum), which rely heavily on not only aquatic, but terrestrial habitats, may face unique challenges on golf courses with heavily modified terrestrial habitat. We conducted a radiotelemetric study of 11 mud turtles inhabiting a local golf course pond in the western Piedmont of North Carolina to investigate their terrestrial activity and habitat selection in a fragmented landscape. In conjunction with radiotelemetry, we used micro-dataloggers to continuously monitor both turtle and environmental temperatures. Mud turtles emerged from the pond from 15 July to 24 November 2006, with the majority of mud turtles emerging in August. On land, mud turtles moved a mean total distance of 182.2 m ranging from 44.7 to 787.9 m and moved a mean straight line distance of 119.3 m ranging from 36.3 to 581.3 m from the pond. On average, mud turtles moved 5 times before selecting an overwintering site. We determined habitat selection using logistic regression by comparing turtle locations with random locations. Mud turtles selected forested habitats with moderate canopy cover, and little to no grass. Mud turtle temperatures were closely correlated with environmental temperatures of the habitat they used (e.g., pond and soil). Data resulting from our studies will assist in developing effective habitat management plans for wildlife on golf courses and other urbanized areas.

Spatial and thermal ecology of diamondback terrapins (Malaclemys terrapin) in a South Carolina salt marsh

Harden, Leigh Anne, Nick A. DiLuzio, J. Whitfield Gibbons and Michael E. Dorcas

Since the 1980’s, east coast barrier islands such as Kiawah Island, South Carolina, have experienced rapid urbanization resulting in alteration of their salt marsh ecosystems. These estuarine ecosystems serve as critical habitat for numerous endemic wildlife species such as diamondback terrapins (Malaclemys terrapin) which, because of their high site fidelity, may be particularly vulnerable to anthropogenic disturbances. To better understand the interactions between terrapins and their environment, we initiated an intensive six-day radiotelemetric study to investigate the daily movements and habitat use of five terrapins within a tidal creek. In conjunction with radiotelemetry, we used microdataloggers to continuously monitor both terrapin and environmental temperatures. We found that during high tides, low tides, and ebbing tides, terrapins spent more time in the marsh (Spartina sp., mud, and occasional shallow water) than in open water of the creek channel. Terrapins moved a mean total distance of 750 m with individual total distances moved ranging from 440 to 1159 m. The mean straight-line distance between the two farthest points was 642.5 m with individual straight-line distances ranging from 287 to 1035 m. We were able to recover micro-datalogger temperature information from two male terrapins and found that from 13 May until 1 June 2006 terrapin carapace temperatures varied from 16.0 to 41.0 C. Comparing these temperatures to environmental temperatures allowed us to make detailed inferences about basking behavior. Our short radiotelemetry study provides new insight to understanding diamondback terrapin habitat use, which will assist in developing predictive models to estimate population sizes.