Population declines of a long-lived salamander: a 20+-year study of hellbenders, Cryptobranchus alleganiensis

Health and Habitat Quality Assessment for the Eastern Hellbender (Cryptobranchus Alleganiensis Alleganiensis) in Indiana, Usa

“…Given the hellbender's fully aquatic nature and mode of reproduction, pesticide exposure could greatly reduce the species reproductive output. Many hellbender populations comprise primarily adults in older age classes and exhibit low reproductive output (Wheeler et al, 2003). Assessing the reproductive output of males is one method of addressing this lack of recruitment at the prezygotic stage.…”

Using the Eastern Hellbender Salamander in a High School Genetics & Ecological Conservation Activity

“…Prosen et al (1998) surveyed ten sites along the River and found only two hellbender specimens, although no historical hellbender data exists for the river. Quantitative evidence of negative trends in hellbender abundance has been recently corroborated in work published by Wheeler et al (2003) whose 20-plus-year study of hellbender abundance shows an average decline of about 77 percent. This recent study focused on both the eastern and the Ozark hellbender and it was designed to yield independent sets of data that were both subspecies-and population-specific.…”

“…However, rigorous quantification of effort is lacking in most hellbender surveys so there are few data to back up these claims. Exceptions to this circumstance, that of Trauth et al (1992) and Wheeler et al (2003) documented drastic declines in hellbenders along rivers in Arkansas (Ozark hellbender) and Missouri (Ozark and eastern hellbender). Although no data were collected to monitor potential causal factors in theses studies the authors speculated that the declines were attributed to factors such as habitat alteration and degradation, elimination of riparian habitats leading to an increase in the silt burden, and water pollution associated with anthropogenic activities.…”

Historic occurrence of the amphibian chytrid ­fungus Batrachochytrium dendrobatidis in ­hellbender Cryptobranchus alleganiensis ­populations from Missouri

“…Spatial and temporal distribution of archived hell benders that were sampled and number of samples positive for Bd (numbers above bars). Data is presented relative to periods of decline (dark gray shading) when eastern hellbender populations regionally declined by about 80%, and Ozark hellbender populations underwent regional declines of about 70% (Wheeler et al 2003). A lack of historic data from the Meramec and Current Rivers precludes knowledge of the timing or intensity of declines in these populations.…”

“…1). Enigmatic range-wide declines of both subspecies, averaging 77%, have occurred in Missouri since the 1980s (Wheeler et al 2003). The initial detection of Bd in Missouri hellbender populations in 2006 and later surveys confirmed presence of the fungus throughout the species' range in the state (Briggler et al 2007(Briggler et al , 2008.…”