Field and Genetic Investigations of larval Movement of the Northern Dusky Salamander, Desmognathus fuscus

Dr. Don C. Forester, Dr. Colleen Sinclair and Dr. Joel W. Snodgrass

Dusky salamanders (Desmognathus fuscus) reach their highest population densities in small headwater streams and decline in number as streams become increasingly larger in size.  Previous studies have documented high nesting densities in headwater streams, suggesting that downstream populations may be supplemented by production in headwaters streams.  Recent studies also indicate very little movement by adults; however, movement during the approximately nine month larval period has not been investigated.  Passive downstream transport of small larvae may serve to connect headwater and downstream populations.  In this study we will use directional traps place at the confluence of small headwater streams and larger downstream channels to directly assess movement of larvae between these two habitats.  We will also use microsatellite markers to assess population structure of Northern Dusky Salamander across a third-order watershed and indirectly assess potential movement of individuals among local populations.  Students will be involved in fieldwork collecting tissue samples, measuring physical habitat, and constructing and monitoring directional movement traps.  In the laboratory student will be involved in DNA isolation and amplification, and microsatellite genotyping.  The results of this study will contribute to our basic understanding of streamside salamander biology, better define the importance of headwater streams for streamside salamanders, and ultimately contribute to the conservation of these secretive organisms.