New Project Underway to Study Threatened Snake at John Muir National Historic Site

Alameda whipsnake

© John Sullivan / Photo 1049672 / May 2014 / iNaturalist.org / CC BY-NC

November 2017 - This fall, the Natural Resources Management Team at John Muir National Historic Site (JOMU) initiated a survey of the Alameda whipsnake (Coluber lateralis euryxanthus). Alameda whipsnakes are a sub-species of the California whipsnake that is only found in the eastern San Francisco Bay Area. The snake's preferred habitat includes chaparral and coastal sage scrubland, and they are a federally and state threatened species, primarily due to loss, fragmentation, and disturbance of these habitats. Although Alameda whipsnakes have been recorded in and around JOMU in recent years, this effort represents the first formal survey.

Funnel traps arranged at the ends of ply-wood "drift fences" have been set up throughout Mt Wanda. Animals that come across the array follow along the fence line and eventually go into the funnel traps.

NPS / Fernando Villalba

In partnership with The Wildlife Project, park staff set out 40 funnel traps arranged along ten drift fence arrays throughout Mt. Wanda for a preliminary two-week trapping session. While they did not catch any whipsnakes, they did find a variety of other species, including ensatinas, arboreal salamanders, California newts, and Pacific tree frogs. The survey will resume with a 90-day trapping session in the spring of 2018, during the peak of the Alameda whipsnake mating season.

Several arboreal salamanders were captured during the fall preliminary trapping session.

NPS / Denise Amador

The project aims to determine whipsnake occurrence and relative abundance in the park and on adjacent land managed by the John Muir Land Trust. This information will help address the current lack of data about how whipsnakes use park resources. Land managers will use the results to inform future decisions related to the restoration and protection of the resources that the whipsnake relies on. Additionally, the project will provide park staff with the training, skills, and experience they will need to qualify for state and federal permits to begin long-term Alameda whipsnake monitoring after this survey ends.

Questions? Contact Fernando Villalba.