Literaturdatenbank
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Tarasan, K., & Delis, P. R. , Demography and morphology of the eastern box turtle (terrapene c. carolina) in a partly agriculturally disturbed habitat, letterkenny army depot, south-central pennsylvania. Paper presented at Third Box Turtle Conservation Workshop.
Added by: Admin (14 Aug 2008 20:33:48 UTC) |
| Resource type: Proceedings Article BibTeX citation key: Tarasan2007 View all bibliographic details  |
Categories: General Keywords: Emydidae, Habitat = habitat, Nordamerika = North America, Schildkröten = turtles + tortoises, Terrapene, Terrapene carolina Creators: Delis, Tarasan Collection: Third Box Turtle Conservation Workshop |
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| Abstract |
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Worldwide declines in herpetofaunal populations, as part of a general biodiversity crisis, are deeply troubling for the scientific community. At least anecdotal reports suggest that reptilian species such as the eastern box turtle, Terrapene carolina carolina, have been undergoing widespread population reductions. Unsustainable use and habitat loss and degradation are two of the main reasons supposedly responsible for these population declines. During 2007, we studied the demography and morphology of the population of T. c. carolina in Letterkenny Army Depot (LEAD) Zone 2, South-Central Pennsylvania, as part of an ongoing long term effort to compile data on the status of its general herpetofauna. The site studied contains two contiguous sub areas (approximately 1,000 ha each); one of relatively pristine northeastern natural habitats and another of habitats intensively disturbed by agriculture. To determine the effects of anthropogenically modified habitat on this population, we surveyed turtles using on foot transects and road cruising throughout the main axes of LEAD Zone 2. These techniques were used for approximately similar amounts of time and effort in the two sub areas: Mountain Side Zone 2 (NAT), a relatively undisturbed habitat, and Buds Lake Zone 2 (AGR), a highly disturbed agricultural habitat. During the first half of the 2007 season, morphological characteristics, frequency of injuries, and age and sex ratios have been preliminarily analyzed. To date, no turtles have been found in the agricultural sub area, while forty turtles have been found in the natural sub area. We found 16 males, 21 females, and 3 juveniles, with the youngest being two years of age. More than half of the turtles found appear to be over 20 years old. Eight turtles were between the age of 15 and 20 and three in the age class of 10 to 15 years old. Most common injuries seem to be chipping and scrapping of the carapace and plastron- with 12 turtles having shells that were not fully intact. Three turtles had one missing leg, one turtle had a missing foot, and four turtles had toes and/or claws missing or injured. There was one incidence of a dermal cephalic tumor. During our study, we have documented three deaths: one caused by road mortality, the second apparently by respiratory infection and the third was of unknown causes as the turtle was found dead and intact in the field. Preliminary findings suggest that box turtles do not utilize the agriculturally impacted zones within LEAD. Routine use of heavy machinery, the dominance of monocultures, the exposed nature of the soils, and other consequences of agricultural practices might deter individuals from inhabiting this area. On the other hand, the relatively pristine habitats seem to have a significant number of individuals, including juveniles, which hints a viable population dynamic. These data and additional information to be collected in future seasons, will advance our understanding of long-term population trends of T. c. carolina in LEAD and aid in the conservation and management of this important species in Pennsylvania.
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