Survival and body condition of captive-reared Juvenile Ozark Hellbenders (cryptobranchus alleganiensis bishopi) following translocation to the wild

We used radiotelemetry and recapture to monitor survival and body condition of 36 captive-reared Ozark Hellbenders (Cryptobranchus alleganiensis bishopi) released at two sites on the North Fork of the White River, Missouri, from May 2008 to August 2009. At the end of our study 16 salamanders were alive, 13 had died, and the fate of seven could not be determined. Captive-reared hellbenders released at a site with densely arranged boulders exhibited approximately 1.5-fold higher annual survival (0.7467; daily survival = 0.9992 ± 0.0004 95% CI) than hellbenders released at a site where boulders were patchily distributed (0.4816; daily survival = 0.9980 ± 0.0007 95% CI). When compared to log-transformed lengthmass relationships developed for wild hellbenders from the same river in the 1970s, mean body condition of hellbenders at the patchy boulder site was about average at the end of the study (mean residual distance = -0.0273 ± 0.0234 SE, n = 7; range = -0.13750.0486), while mean body condition of hellbenders at the dense boulder site was above average (mean residual distance = 0.0423 ± 0.0402 SE; n = 8; range = -0.03740.1088). In addition to lower survivorship and body condition, a greater proportion of hellbenders at the patchy site accrued physical abnormalities (6 of 13 vs. 2 of 14), carried leech parasites (9 of 16 vs. 4 of 14), and carried the fungus Batrachochytrium dendrobatidis (3 of 11 vs. 1 of 13). A 'site only' model of survival was most supported, though additional supported models suggested increased mass at release may have increased daily survivorship. While more work is needed to determine the impact of translocation on long-term population dynamics of Ozark Hellbenders, our study demonstrated that about half of a translocated population of captive-reared hellbenders can survive while maintaining or increasing in body condition during their first year post-release, given release sites are well selected.