Tricolored Blackbirds

Tricolored Blackbirds have been disappearing from California’s wetlands since the 1930’s. Previous attempts to address this loss have failed due to a lack of a reliable evidence of a population trend, or information about what might be driving it. Tricolored Blackbirds are challenging to study; they do not reliably breed or overwinter in the same sites year after year, so it is difficult to know where to monitor colonies in any given year. With the support from Carol and Russ Faucett, annual unrestricted funds, and grant money, we partnered with UC Davis and California Audubon to generate the first population analysis for Tricolored Blackbirds. We used year-round observations in eBird, leveraging the ability of eBirders to submit checklists from any location and maximized the spatial coverage of our data relative to other past field studies. We combined eBird observational data with existing banding and nesting data to show that Tricolored Blackbird populations have likely declined by 34% over the last ten years. The California Department of Fish and Wildlife cited our work as the best available science and recommended the listing of the species under the California Endangered Species Act. At a hearing on April 19 our research (in press in Biological Conservation) was heavily cited, and the vote was 4-0 in favor of listing the species as threatened! We now hope to work with our partners in California to help guide and inform a Recovery Plan, and continue to make an impact on the conservation of this iconic species.