Sampling Considerations for Amphibian Surveys: Evaluating Risks of Committing Type I and Type II Errors

Global amphibian declines pose a major threat to the world’s biodiversity. We examined the observation bias associated with volunteer based anuran surveys, such as the North American Amphibian Monitoring Protocol (NAAMP). We followed NAAMP protocol to examine if variation in the persons (1-3) in an observer unit affected observer error. We hypothesized that observation units with multiple observers have less observer bias and would better report anuran assemblages compared to single observers. Larger observer units had fewer incidences of false positive observations. Additionally, we attempted to determine which sampling method for the eastern hellbender (Cryptobranchus a. alleganiensis) had the highest detection rate. We examined the detection probability of three methods: visual encounter surveys (VES), nocturnal spotlighting, and un-baited trapping. After 200 search hours and 300 trap nights, one hellbender was detected during a VES. Due to the small sample size we were unable to determine site occupancy and detection probabili

SEASONAL INCIDENCE OF CAPTURE AND REPRODUCTION OF FIVE FOSSORIAL SNAKE SPECIES IN WEST VIRGINIA

Museum specimens of five species of fossorial snakes collected in West Virginia during 1930–2000 were examined to determine monthly incidence of capture, adult body sizes, reproductive cycle, and clutch characteristics. Captures occurred over the shortest time in the year in the Eastern Earthsnake (Virginia valeriae valeriae) and Northern Red-bellied Snake (Storeria occipitomaculata occipitomaculata) and were longest in the Northern Brownsnake (S. dekayi dekayi). Male gonadal cycle conformed to the temperate pattern, whereas that of females tended towards a tropical pattern. Incidence of females nearing oviposition or parturition was highest during June–July for all species, and length of their reproductive seasons were generally in keeping with those of northerly populations of the respective species. Mean clutch sizes were largest in the Northern Brownsnake (mean = 20.5) and smallest in the single oviparous snake, the Eastern Wormsnake (mean = 2.8). Adult body sizes were similar to respective populations elsewhere within their ranges. The Mountain Earth Snake (V. pulchra) was the least represented species in this study. A meaningful degree of predictability existed in the life history traits examined in our study as they related to geographic trends of this Allegheny snake assemblage