Alameda whipsnake/striped racer research project, by Jessica Sheppard

By Jessica Sheppard, Resource Analyst, East Bay Regional Park District, with input from Doug Bell, Wildlife Program Manager, EBRPD and Ricka Stoelting, Research Associate, Swaim Biological, Inc. Edited by Kay Loughman.

Claremont Canyon Regional Preserve is hosting a research project focused on the Alameda whipsnake (Masticophis lateralis euryxanthus), also sometimes referred to as the Alameda striped racer (Coluber lateralis euryxanthus). This elusive and speedy snake is protected at the state and federal level and may be found in the park.

The East Bay Regional Park District is implementing its 2010 board-approved Wildfire Hazard Reduction and Resource Management Plan in the East Bay Hills to lower the risk of catastrophic wildfires. Because this plan calls for altering some habitat of the Alameda whipsnake, the US Fish & Wildlife Service called for several mitigation measures, including designing and implementing a study to determine how Alameda whipsnakes might be affected by the fuels management activities.

Swaim Biological Inc. has been hired to implement the US Geological Survey study protocol, titled “Measuring the response of the Alameda striped racer Masticophis lateralis euryxanthus to fuels management in the East Bay Regional Park District, California” by Richmond et al. (2015). Karen Swaim has been studying the Alameda whipsnake for over 25 years, and holds a US Fish and Wildlife Service Threatened and Endangered Species Recovery Permit.

The Swaim team has placed traps* throughout several District parks in potential Alameda whipsnake habitat. Traps were activated in mid-April and are checked daily. Captured snakes are marked, measured, weighed and released on-site. This intensive trapping will continue through spring, concurrently with vegetation reduction in certain pre-designated areas. Trapping and vegetation treatments will take place over the next five years. The results of this study should provide information on the population of Alameda whipsnakes in Claremont Canyon and elsewhere, as well as help us understand how vegetation treatments affect whipsnake movements throughout their habitat.

To monitor snake response, the researchers use drift-fence funnel trap surveys. A drift-fence funnel trap, is basically a length of 1-2’ tall, thin fenceline (plywood, erosion-control fabric or other material) inserted into the ground to a slight depth (say 2” covered by soil) at whose terminal ends can be found box-style traps (in this case, wire mesh panels covering a wooden frame) with one or two large funnels projecting from inside the traps onto the fenceline. Upon approach to a drift fence, a snake or lizard or other small mammal typically will orient parallel to and travel along the length of the fence until it reaches the end of the line where it slithers, slinks or crawls right into the funnel trap.

If you come across a trapline during your hikes, please be respectful of this very sensitive research project; and inform Park District if any evidence of vandalism is observed. Thank you for your assistance.