Literaturdatenbank
Literaturdatenbank |
|
 |
|
Richter, A., Johansen, E., O'Connell, T., & Fox, S. F. , Road mortality in terrapene carolina and t. ornata: Are females more at risk? (poster). Unpublished paper presented at 2013 Box Turtle Conservation Workshop.
Added by: Admin (06 Jan 2014 18:25:15 UTC) |
| Resource type: Conference Paper BibTeX citation key: Richter2013a View all bibliographic details  |
Categories: General Keywords: Habitat - habitat, Nordamerika - North America, Schildkröten - turtles + tortoises Creators: Fox, Johansen, O'Connell, Richter Collection: 2013 Box Turtle Conservation Workshop |
Views: 7/695
Views index: 18% Popularity index: 4.5% |
| Abstract |
|
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.
Added by: Admin |