Alameda Whipsnake: Caught Speeding on Mt. Wanda, Sporting Yellow Racing Stripes

A juvenile Alameda whipsnake caught and released in the rocky outcrops of a small chaparral community. This was one of four individuals caught in the spring 2019 monitoring season.

NPS / Angel Sprague

February 2020 - The Natural Resource Management (NRM) team at John Muir National Historic Site (JOMU) is continuing its multi-year effort surveying for populations of the Alameda whipsnake, which occurs within the park on Mt. Wanda. Also known as a striped-racer, the Alameda whipsnake has been a federally listed species since 1997. As reported in December 2018, the NRM team was working cooperatively with The Wildlife Project to conduct these surveys. In January 2020, the NRM team was issued a U.S. Fish and Wildlife Service recovery permit for Alameda whipsnakes, under section 10(a)(1)(A) of the Endangered Species Act. All current and future surveys will be conducted under this permit and supervised by authorized biologists.

This adult Alameda whipsnake was caught and released in one of the two major trap site hotspots, next to a historic olive orchard and chamise shrubland.

NPS / Angel Sprague

Survey efforts continued into spring 2019, which resulted in four new individual captures. Over all four trapping seasons between fall 2017 and spring 2019, the team captured a total of 34 Alameda whipsnakes, including 26 “new” captures and eight “recaptures.” Of the 34 snakes captured, 26 were male and eight were female, resulting in a sex ratio of 3:1, male to female. This is an extreme ratio which could be due to higher movement patterns seen in male whipsnakes: males traveling through the habitat more frequently may have an increased likelihood of being captured and recaptured. Of the eight recaptures, six were male and two were female. Statistical predictive models on all current data have resulted in an estimated population range of 30-92 Alameda whipsnakes, and a likely population size of about 52. There was an increase in trapping success and an increase in the predicted population over the four trapping seasons.

Drift fence arrays are successful designs in controlling the movement of particular ground-dwelling species. This one is situated next to a historic olive orchard and small chaparral community.

NPS / Angel Sprague

These surveys continue to highlight significant, active populations of Alameda whipsnakes on Mt. Wanda. The Alameda whipsnake final report, prepared by The Wildlife Project and JOMU NRM, and subsequent findings, will provide meaningful contributions to the Mt. Wanda Comprehensive Site Management Plan currently being developed. It is essential that the NRM team continue its monitoring work to inform decision-making and to develop the best management practices on Mt. Wanda for protecting this threatened species.

Please contact Natural Resources Lead Angel Sprague or Chief of Resource Management and Planning Gretchen Stromberg for more information.

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