Survival Estimates for Adult Eastern Hellbenders and Their Utility for Conservation

The Eastern Hellbender (Cryptobranchus alleganiensis alleganiensis) is a large, completely aquatic salamander native to the eastern United States. Hellbender populations have experienced numerical declines and range contractions over a large geographic area, but few demographic data are available to allow biologists to diagnose specific causes of the declines. We estimated survival of Hellbenders in Indiana using radio telemetry. We monitored 21 adult eastern Hellbenders during July 2008–October 2009 and documented three mortalities. Using a known-fate model, we estimated annual survival as 0.804 (±0.089 SE). This estimate is lower than expected for a long-lived species and signals the continued decline of Hellbenders in Indiana. Estimates of survivorship such as this provide baseline data for translocation programs and are useful in parameterizing population models.