Comparison of Movement Patterns in Captive-Released Eastern Hellbenders (Cryptobranchus alleganiensis alleganiensis) Using Three Different Release Methods

Eastern hellbender (Cryptobranchus alleganiensis alleganiensis) population size has declined throughout much of its range. Previous captive-release headstarting programs have resulted in minimal success, presumably due to movement of captive-released animals away from the release site. This study aimed to increase the success of hellbender headstarting programs by assessing the effectiveness of three release methods. Releases were conducted in two stream sites within the Allegheny River drainage. Streams were similar; however stream A contained a higher boulder density. In each site, three salamanders were placed individually in cages, three salamanders were placed individually in nest boxes with the entrance blocked with screen, and three salamanders were released directly under cover rocks. Animals were monitored between 18 June 2013 and 12 October 2013 using radio telemetry. Results showed little difference in total movement and survivorship between stream sites or treatments. Number of movements was marginally significantly higher in stream B. The number of movements was not different between release types. Overall survival was low; only three animals were found alive for longer than six months. Four animals were never recovered, three were found dead, and eight transmitters were found. Movement was most dependent on the phase of the moon. Both distance and frequency of movement increased with greater moon phase. Captive-released animals generally moved further than what has been reported in wild hellbenders, with an average cumulative distance moved of 653±138 m (SE). The information gathered from this study could aid further captive-rearing projects, as well as inform monitoring and survey efforts