Harvesting as a factor in population decline of a long-lived salamander; the Ozark hellbender, Cryptobranchus alleganiensis bishopi Grobman

Abstract

We documented the harvesting of 558 Ozark hellbenders, Cryptobranchus alleganiensis bishopi, between 1969 and 1989, from the North Fork of the White River (NFWR), Ozark County, Missouri. Scientific studies accounted for 272 individuals. More than 256 Ozark hellbenders were taken for the pet trade for suppliers in Michigan, New Jersey, and Japan by collectors from Nebraska and Alabama. During the first weekend of September 1980, 171 were collected illegally. Estimates indicate that approximately 50% of the females were removed from the most significant hellbender habitat in the NFWR (riffle 2-3) that weekend. Between 1969 and 1980, coordination with the Missouri Department of Conservation helped insure that C. a. bishopi, used for scientific research, were not removed from a 2.67 km (NFWR 1) research section. Population estimates from 1970 and 1978 studies indicate stability in the most densely populated habitat. In the 1970's, larger samples of individuals collected for research were not removed from a single site, but a few individuals were collected from multiple sites within a 10 km reach of the NFWR. During 1982-1984 more than 100 individuals were removed from the same section as in 1980 by commercial collectors. This evidence supports harvesting of C. a. bishopi, especially illegal harvesting, as a contributing factor in the decline of this population and documents that the decline had begun by 1980.