Status and management of the relict leopard frog, Rana onca , in southern Nevada and northern Arizona

Authors: Ross D. Haley, Dana Drake, Jef Jaeger, Jon C. Sjoberg

Year: 2008 (xl)

Abstract

First described by Cope in 1875 from a single specimen collected in the Virgin River basin of southwestern Utah, the relict leopard frog, Rana onca, was considered to be extinct for approximately 36 years until its rediscovery at several locations within the Lake Mead National Recreation Area (NRA), Nevada, in 1991. From 1991-1995 a total of seven populations were identified, six within Lake Mead NRA and one in Mohave County, Arizona. Of these seven, two were extirpated by 1998 and one more was apparently extirpated in 2007. The global population of this species was thought to number fewer than 1100 individuals in 2000 (Bradford et al., 2004, Southwestern Naturalist 49(2):218-228). Conservation efforts for this species are complicated by its historic distribution encompassing trans-boundary areas of three states, and multiple jurisdictional areas of federal management agencies. Coordinated conservation actions were initiated in 2001 with formation of the Relict Leopard Frog Conservation Team (RLFCT) and a comprehensive Conservation Agreement and Strategy (CAS) was completed in fall 2005. In accordance with the CAS, the RLFCT partners have successfully implemented captive breeding and head-start programs, established five additional populations in the wild, re-introduced frogs at one site of recent extirpation, conducted habitat improvement projects, completed critical life history research activities, and have developed a cooperative field monitoring program. Current efforts are focused on management of existing wild and experimental populations, and on developing additional viable populations near or within historic range.