title: Terrestrial distribution of pond-breeding salamanders around an isolated wetland.
abstract: Terrestrial habitats surrounding isolated wetlands are a critical resource for many pond-breeding amphibian species, yet few studies have examined the terrestrial distribution of post-metamorphic juveniles and adults. We used an encircling drift fence at a breeding pond in conjunction with partial fences at 90, 172, and 332 m from the wetland to estimate the terrestrial distribution of adult marbled salamanders (Ambystoma opacum; four breeding seasons) and mole salamanders (A. talpoideum; two seasons), as well as the dispersion of newly metamorphosed A. opacum (one summer). For newly metamorphosed A. opacum, 79% emigrated < 90 m from the wetland, and 8% moved beyond 172 m; movement distance was unrelated to body size. Distribution of adult A. opacum varied among years, with an average of 28% (range 23-31%) occurring beyond 172 m in all years. Averaged across two years, 51% of adult A. talpoideum occurred beyond 172 m. Lognormal models provided a good fit to both the juvenile and adult ambystomatid distributions, and parameters differed between age classes, sexes, species, and years within species. For adult A. opacum a buffer radius of 300 m or 340 m, depending on the year, is estimated to include 95% of adults; for A. talpoideum the estimate is 464 m or 501 m. A reanalysis of distribution data for seven ambystomatid species shows that a previous estimate of a 164-m radius to protect 95% of a population underestimates the needed buffer radius by 185 m. Because our study wetland requires a nearly 500 m wide radius to protect 95% of its ambystomatid adults, preservation of similar communities may require much more surrounding terrestrial habitat than previously thought.
authors.affiliation: Savannah River Ecology Laboratory, University of Georgia, Drawer E, Aiken, South Carolina 29802-1030, USA. dsopacum@gmail.com
authors.forename: David E
authors.initials: DE
authors.lastname: Scott
authors.affiliation: Swansea High School, Swansea, South Carolina 29160, USA.
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Komoroski
authors.affiliation: Swansea High School, Swansea, South Carolina 29160, USA.
authors.forename: Dean A
authors.initials: DA
authors.lastname: Croshaw
authors.affiliation: Swansea High School, Swansea, South Carolina 29160, USA.
authors.forename: Philip M
authors.initials: PM
authors.lastname: Dixon
mesh_terms: D000818:Animals; D003710:Demography; D005260:Female; D008297:Male; D012098:Reproduction; D012737:Sex Factors; D014562:Caudata / Q000502:physiology*; D053833:Wetlands