Current Address:

Restoration Ecology Lab
Archbold Biological Station
P.O. Box 2057
Lake Placid, FL 33862

Postdoctoral Research:
I was a postdoctoral researcher at the University of Georgia's Savannah River Ecology Lab from September 2003 to May 2006. The main focus of my research was the LEAP (Land-Use Effects on Amphibian Populations) study in South Carolina. More information… http://www.uga.edu/srelherp/LEAP/

Dissertation Research:
Movement behavior, migratory success, and demography of juvenile amphibians in a fragmented landscape

Abstract:
I used experimental approaches to investigate movement behavior and growth and survival of juvenile amphibians in fragmented landscapes. Larvae of three species (spotted salamanders Ambystoma maculatum, small-mouthed salamanders A. texanum, and American toads Bufo americanus) were added to artificial pools on forest edges. Initial orientation of A. maculatum and B. americanus was significantly biased toward forest. A. maculatum moved more than eight times farther and toads more than three times farther into forests than into fields, and recapture rates of both species were much lower in fields. Juvenile salamanders also experienced higher dehydration rates in fields. In a separate experiment, I released A. maculatum and B. americanus larvae into artificial pools in pastures 5 to 50 m from forest edges. Metamorphosed salamanders oriented non-randomly at nine pools, but at only one was movement direction consistent with direction to the nearest forest edge. Emigrating salamanders likely responded to distinct features of each pool, rather than distant cues. Migratory success of both species declined with increasing distance to forest. Less than 15% of salamanders and toads released from 50-m pools reached the forest. To investigate the consequences of habitat choice, I raised juvenile spotted salamanders and marbled salamanders (A. opacum) in terrestrial enclosures in old fields, forest interior, and edge habitats for two years. Most mortality occurred during the first summer post-metamorphosis. Only 3.1% of juveniles survived the first summer in old fields. High temperatures in fields during summer likely caused mortality due to heat stress and desiccation. Larger metamorphs had greater chances of surviving until the first fall. Overall survivorship of A. opacum was 2.3 times higher than A. maculatum, perhaps due to the difference in timing of metamorphosis. I found no evidence of edge effects on demographic traits, nor of density-dependent effects on growth rates. Behavioral avoidance of, and lower survival in, fields imply that forest fragmentation is likely to reduce dispersal rates between local populations, with negative consequences for population persistence of the species tested. Similarly, breeding sites lacking connectivity to forest may be population sinks for some ambystomatid salamanders because juveniles suffer high mortality during emigration.

Rothermel, B.B. and R.D. Semlitsch. 2006. Consequences of forest fragmentation for juvenile survival in spotted (Ambystoma maculatum) and marbled (A. opacum) salamanders. Canadian Journal of Zoology 84(6):797-807.

Rothermel, B.B. 2004. Migratory success of juveniles: a potential constraint on connectivity for pond-breeding amphibians. Ecological Applications 14(5):1535-1546.

Rothermel, B.B. and R.D. Semlitsch. 2002. An experimental investigation of landscape resistance of forest versus old-field habitats to emigrating juvenile amphibians. Conservation Biology 16(5):1324-1332.

Semlitsch, R.D. and B.B. Rothermel. 2003. A foundation for conservation and management of amphibians. Pages 242-259 in: Semlitsch, R.D., editor. Amphibian Conservation. Smithsonian Institution Press, Washington, D. C.

Boone, M.D., C.M. Bridges and B.B. Rothermel. 2001. Growth and development of larval green frogs (Rana clamitans) exposed to multiple doses of an insecticide. Oecologia 129:518-524.

Boone, M.D., R.D. Semlitsch, J.F. Fairchild and B.B. Rothermel. 2004. Effects of an insecticide on amphibians in large-scale experimental ponds. Ecological Applications 14(3):685-691.

Rittenhouse, T.A.G., M.C. Doyle, C.R. Mank, B.B. Rothermel and R.D. Semlitsch. 2004. Substrate cues influence habitat selection by spotted salamanders. Journal of Wildlife Management 68(4):1151-1158.

Master's research:
Balcom, B.J. and R.H. Yahner. 1996. Microhabitat and landscape characteristics associated with the threatened Allegheny woodrat. Conservation Biology 10(2): 515-525.