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Our next meeting will be Monday, November 18th, 7PM at the Caspar Community Center 15051 Caspar Rd, Caspar, CA 95420.

Marbled Murrelet Restoration, Corvid Management and Conditioned Taste Aversion

The decline of Marbled Murrelet (Brachyramphus marmoratus) populations in California, Oregon and Washington has been linked to strong predation pressure on murrelet nests by corvids, especially Steller's jays (Cyanocitta stelleri). Jays thrive in the fragmented and recreationally used forests that are also used by murrelets for nesting. As an alternative to lethal control of jay populations (which can be logistically difficult and potentially counterproductive), a unique management action was implemented to modify jay behavior in central California. Jays were exposed to murrelet colored and sized eggs that had been treated with a chemical that causes temporary discomfort and possibly vomiting when ingested by jays. This exposure was used to induce an aversion to the murrelet-mimic eggs. From 2012-2015 California State Parks, placed thousands of murrelet-mimic eggs throughout State and County Parks. Results suggest that predation could be reduced by as much as 80% when using this technique. Conditioning was successful for the majority of resident jays in the treated areas of the parks. Conditioned taste aversion treatment appears to be a promising and cost-effective management technique that can complement other management actions that already implemented to improve reproduction of murrelets on the Pacific coast. In time, at-sea surveys for juvenile murrelets may give a better indication of the ultimate success of this management approach.

Portia Halbert Portia Halbert is a Senior Environmental Scientist with the Santa Cruz District of California State Parks. For 19 years she has been part of a resource management team that works to manage parkland and restore habitat in the 70,000 acres of Parks in Santa Cruz and San Mateo counties. Her experience is based on a wide variety of things she has had the opportunity to do, such as restoration using heavy equipment for earthmoving, planting and maintaining large areas with native plants, refining the work on invasive exotic plants and incorporating early detection and rapid response, and working with sensitive species such as the marbled murrelet, California red-legged frog and San Francisco garter snake. As a last and personal favorite, she is also a member the statewide burn crew, helping to reintroduce fire to the landscape; through this work she has discovered that everyone is a closeted pyromaniac. In her consulting business she conducts inland surveys for the marbled murrelet, and eradicates non-native plant species. She is a member of the California Invasive Plant Council, and is Vice President of the Santa Cruz Mountains Bioregional Council.


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