A survey of amphibian and reptilian populations in Huron County, Michigan, with a comparative analysis of 1908 vs. 1996 species richness and relative abundance

Scientists have become concerned about an apparent decline in amphibian populations around the world. Comprehensive amphibian surveys are needed to provide a benchmark for species' presence and abundance, and against which future surveys may be compared. For those areas where comprehensive surveys have been conducted in the past, surveys are needed to compare with the past surveys' species' presence and abundance. The intent of the research here described was to survey a site in Michigan that was surveyed in the past, and also to compare the data from the current and past surveys to suggest possible amphibian population changes.;The 1996 survey repeated another conducted in 1908 of an area in Huron County, Michigan. The 1908 investigation described the surveyed sites as in the Rush Lake area. Without more specific detail on the sites, it was impossible to repeat the survey in an identical manner. Instead, the 1996 investigation utilized a randomized technique that incorporated many different habitats. The 1996 survey can now be used as a basis against which other future investigations of the same area can be compared. An additional 1997 survey was added to include the breeding season for many amphibians.;The 1996 Rush Lake survey findings indicate that three species of amphibians and five of reptiles may have experienced population declines between 1908 and 1996. Two amphibian--Rana catesbeiana and Pseudacris t. triseriata--and three reptilian species--Chrysemys picta marginata, Lampropeltis t. triangulum and Nerodia s. sipedon--that were located in 1908 were not found in 1996. Other species located in 1996, but in what appeared to be reduced numbers compared to 1908, included: Thamnophis s. sirtalis, T. sauritus septentrionalis, and R. clamitans melanota. Additional monitoring and surveying of the herpetofauna in the Rush Lake area is recommended to determine the extent of possible declines and to provide information about potential population fluctuations.