Meeting Abstract

103.3  Tuesday, Jan. 7 08:45  The effects of urbanization on physiological stress of Jollyville Plateau salamanders, Eurycea tonkawae BENDIK, NF*; DAVIS, DR; ZABIEREK, K; GABOR, CR; City of Austin; University of South Dakota; Texas State University; Texas State University nathan.bendik@austintexas.gov

Jollyville Plateau salamanders (Eurycea tonkawae) are aquatic neotenes endemic to two highly populated counties in central Texas. Much of the species’ range has been negatively impacted by anthropogenic disturbance, exhibiting low population densities and declining trends in heavily urbanized watersheds. Gross changes in water chemistry have occurred in these areas due to the release of pollutants from a wide variety of sources associated with urbanization. At the same time, increases in flash flooding and sedimentation have altered the physical environment. Assessing stress levels in field-caught animals may provide important insights into population health. Using a recently developed technique to evaluate water-borne stress hormone levels, we compared corticosterone (CORT) levels of salamanders across populations in two urbanized and two non-urbanized sites. We found that salamanders from urbanized sites had significantly higher CORT levels than salamanders from non-urbanized habitats. Our results indicate that anthropogenic disturbance may be contributing to elevated CORT levels in populations of E. tonkawae. Further evaluation of stress hormone levels in E. tonkawae may help elucidate the mechanistic link between the ‘urban stream syndrome’ and population declines in this federally threatened species.