HCP IMPLEMENTATION AND ADAPTIVE MANAGEMENT AT A SANTA CRUZ LONG-TOED SALAMANDER BREEDING POND
|Mark L Allaback; Biosearch Environmental Consulting; firstname.lastname@example.org; Chad W. Steiner, David M. Laabs, Chad Mitcham, Chad W Steiner
The endangered Santa Cruz long-toed salamander (SCLTS; Ambystoma macrodactylum croceum) inhabits a restricted range and is in decline due to multiple stressors including climate change, habitat loss, and competition with nonnative species. From 2007 to 2017, we implemented a Habitat Conservation Plan (HCP) at Tucker Pond in Santa Cruz County. The HCP required control of nonnative American bullfrogs (Lithobates catesbeianus), specifically culling and annual pond draining. Bullfrogs were successfully eliminated by 2015. However, three pitfall trapping studies conducted under the HCP documented lower numbers of breeding SCLTS adults (~200-400) as compared with a baseline estimate (~1,000 in 2001-02). Over the same period, relative abundance of native rough-skinned newts (RSN; Taricha granulosa) increased exponentially, with nearly 7,000 adult captures in 2016-17. Observations of predation by RSN on SCLTS eggs were documented. We are concerned that high numbers of predatory RSN in the pond could result in extirpation of an already depressed SCLTS population. Annual pond draining, timed to favor SCLTS transformation, is ongoing. In addition, a study testing the effectiveness of a mesh fence, designed to permit free movement of SCLTS while restricting entry by larger RSN, was initiated in 2017 and continues to the present.