Tricolored Blackbird Population at Atwell Island Continues to Expand

The population has nearly tripled over the past three weeks.

A recent image of Tricolored Blackbirds protecting their nests at Atwell Island.

As reported in our last Medium story, Tricolored Blackbirds have returned to Atwell Island, a restored wetland in Tulare County, Calif., for a third straight year.

In late April, approximately 1,000 Tricolored Blackbirds were seen on site. Over the past few weeks, this population has grown to 4,000 birds — and is expected to continue to increase in size. Females can be seen carrying nesting material into a 40-acre parcel primarily consisting of cattails.

Atwell Island is managed by the federal Bureau of Land Management, with assistance from USDA’s Natural Resources Conservation Service in California. NRCS anticipates this colony could continue to grow to at least 10,000 birds over the coming weeks — similar to the 2014 and 2015 populations.

For three straight years, colonies have been attracted to Atwell Island due to its safe and productive habitat for the birds away from active farming operations. The long term plan for NRCS and partners is to find scientific solutions to attracting these birds off dairy farms to restored wetlands — like Atwell Island — for long term sustainability.

To see video of Atwell Island’s 2015 colony (which became home to approximately 20,000 birds) please visit: https://youtu.be/iRxSC3H2oyk

Atwell Island provides safe and sustainable conditions for Tricolored Blackbirds to nest yearly. Sometimes multiple times per year.

In addition:

Dairymen throughout California’s Central Valley are answering the call for conservation to help save Tricolored Blackbird colonies through the USDA Natural Resources Conservation Service (NRCS) Regional Conservation Partnership Program (RCPP) Tricolored Blackbird Initiative. Colonies are actively in their nesting cycles, with sometimes over a thousand fledglings being observed.

Tricolored Blackbirds build large colonies of nests in the Central Valley areas that were once marshy ecosystems and are now cropland. The typical nesting cycle lasts approximately 35 days, before the young birds can safely leave their nest.

About 43 percent of the birds now use silage crops such as triticale and wheat to build their nests. Since Tricolored Blackbirds are colonial nesters, thousands of birds may impact — and be impacted by — farming operations where they build their nests. The species is now federally listed as a Bird of Conservation Concern, is protected under the California Endangered Species Act, and also protected under the provisions of the Migratory Bird Treaty Act.

NRCS provides an incentive payment to the property owner to offset the cost of delaying their harvest due to lost value in the silage. Over the past four years, farmers’ participation has resulted in nesting success for tens of thousands of birds.

Furthermore, NRCS works with conservation partners like Audubon California, Dairy Cares, the Farm Bureau, Sustainable Conservation, and Western United Dairymen through the RCPP Tricolored Blackbird Initiative. The long term goal is to invest technical and financial resources to create or improve wetland habitat, on land adjacent to farms, for the birds to nest there for long-term sustainability.


A baby Tricolored Blackbirds waits for its mother’s return … with food.

Check back soon for another story and updated information on the 2016 Tricolored Blackbird nesting season. For questions, please contact NRCS at (530) 792–5692.

To learn more about federal assistance available to dairy farmers with active colonies, a recent news release can be found at: http://go.usa.gov/cu5yH

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