Literaturdatenbank
Literaturdatenbank |
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Cook, R. P. (1996). Movement and ecology of eastern box and painted turtles repatriated to human-created habitat. Unpublished thesis , City University, New York.
Added by: Sarina Wunderlich (12 Dec 2010 20:43:02 UTC) |
| Resource type: Thesis/Dissertation BibTeX citation key: Cook1996 View all bibliographic details  |
Categories: General Keywords: Chrysemys, Chrysemys picta, Emydidae, Habitat = habitat, Nordamerika = North America, Schildkröten = turtles + tortoises, Terrapene, Terrapene carolina Creators: Cook Publisher: City University (New York) |
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| Abstract |
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The feasibility of repatriation as an approach to conservation and population restoration in the eastern box turtle (Terrapene Q. carolina) and the eastern painted turtle (Chrysemys p. picta) was studied at Floyd Bennett Field, Brooklyn NY. The 579 ha site, originally salt marsh filled in to construct an airport, consists of mid-successional habitats such as grasslands, native shrub thickets, developing woodlands, and mixed stands dominated by giant reed (Phragmites australis). The site is now managed by the U.S. National Park Service for recreation and ecological restoration. Prior to this project, the site did not support populations of these species. Eastern box and painted turtles were collected and released after data on size, weight, age, and sex were recorded. In 1990, 55 painted turtles were released into a 0.3 ha pond created in 1989. These individuals were monitored using funnel traps through the end of 1993. From 1987 through 1990, 335 box turtles were released into developing wocdlar.ds I most after 30 days in an acclimation pen. Fifty three individuals were fitted with radio-transmitters and monitored for up to seven years. Additional data were obtained through active search and the use of a Labrador retriever. Recapture rates of ~. picta ranged from 87.8% to 97.7 % annually, indicating they rernained at the release pond and had high survi val. Growth varied by sex and age, and fecundity was estimated at 11.7 eggsjadult femalejyear. Rates for these parameters were comparable to similar non-repatriated populations. Though individually variable, ~. carolina tended to disperse homeward after release. Of the 53 radio-tagged individuals, 13 (24.6%) left the site, 25 (47.2%) established horne ranges, and 15 (28.3%) died before sufficient data were collected. Most individuals radio-tracked long term established horne ranges within a kilometer of the release point. Sorne may disperse greater distances. Of the 25 individuals that established horne ranges, 17 (68%) did so in the release year, two (8%) in outyear #1, three (12%) in outyear #2, and three (12%) in outyear #3. These generally positive results were mitigated by low rates of survival. Annualized survival of T. carolina for five years post-release was 71%, with lowest survival in the first two years. Principal causes of "mortality" were dispersal from the site and pneumonia, both of which were greatest initially, plus winter kill, a randorn event. Annualized survival for the final three years was 84%. Patterns of growth, horne range size, activity season, habitat use, annual reproductive output, and production of young were generally comparable to similar populations of T. carolina not subject to repatriation. These results, based on short to interrnediate-term rnonitoring indicate that ~. picta rnay be easily repatriated, but that T. carolina is more difficult. Assuming a circular shape, release sites for T. carolina need to be at least 300 hectares of predominantly woody habitat in order to retain most individuals, and initial mortality rates may be relatively high. Data on behavioral and reproductive parameters suggest that a population is in the process of becorning established, but conclusions on long-term results will require follow-up assessment after another 20-30 years.
Added by: Sarina Wunderlich |