Center for Biological Diversity

For Immediate Release, August 19, 2015

Contact: Jeff Miller, (510) 499-9185,

California Given a Third Chance to Protect Endangered Tricolored Blackbirds

SACRAMENTO, Calif.— The Center for Biological Diversity today petitioned to protect tricolored blackbirds under the California Endangered Species Act — its third attempt in the past decade to gain protection for a unique California bird species that is declining at a rate comparable to the extinction of the passenger pigeon.

Tricolored blackbird
Photo courtesy USFWS. Photos are available for media use.

“There’s no question that tricolored blackbirds require protection to avoid a continued slide toward extinction,” said the Center’s Jeff Miller. “The California Fish and Game Commission needs to stop playing roulette with our native species. We could lose tricoloreds entirely if protection for their vulnerable breeding colonies is delayed any longer.”

Tricolored blackbirds — which once formed massive nesting colonies of millions of birds in California’s Central Valley — have declined dramatically due to destruction of wetlands and native grasslands, shooting, pesticide use, and mass destruction of nests through mowing and harvest of crops tricoloreds use for nesting. Comprehensive statewide surveys found only 395,000 tricoloreds in 2008, followed by a decline to 259,000 in 2011 and only 145,000 in 2014 — the smallest population ever recorded.

The Center first petitioned for emergency protection for tricoloreds in 2004. The Fish and Game Commission ignored the recommendation of experts familiar with the species and rejected the petition. After a decade of further population declines, the Center petitioned again for emergency listing in October 2014. In December 2014 the commission determined the status of tricoloreds was precarious and by a 3-2 vote implemented emergency protections from nest destruction and shooting. Those protections expired in June 2015. With two commissioners absent, the commission made a bizarre and contradictory finding, voting 2-1 that there was not enough information to move the species toward permanent protection. On Aug. 5, 2015 the full commission, with two new commissioners, acknowledged its June 2015 finding was unsupportable but refused to revisit the decision, despite testimony from ornithologists that the remnant breeding populations are in imminent danger of extinction.

“The commission was legally required to initiate a status review for the species based on the 2014 tricolor petition,” said Miller. “Out of an abundance of caution, we’re initiating this parallel process because our primary concern is to get protections in place as soon as possible.”

The tricolored blackbird (Agelaius tricolor) breeds in dense colonies in California’s Central Valley, coast ranges and Southern California. More than 99 percent of tricolors live in California; the primary breeding range is the Sacramento and San Joaquin valleys. Adult males are a glossy blue-black with striking red and white shoulder patches, while females are mostly black with a small reddish shoulder patch. Tricolored blackbirds typically eat insects but will also take grains, snails and small clams.

Tricoloreds form the largest breeding colonies of any North American land bird, with a single colony often consisting of tens of thousands of birds, as a defense again predation. In the 1800s one observer described a wintering tricolored flock in Solano County as “numbering so many thousands as to darken the sky for some distance by their masses,” and in the 1930s a biologist reported a flock of more than a million tricoloreds in the Sacramento Valley. Tricolored numbers declined in the Central Valley at least 50 percent between the 1930s and early 1970s, and an additional loss of more than half the remaining population was reported from 1994 to 2000.

Forced from their natural nesting sites by conversion of wetlands and native grasslands to urban and agricultural development, many tricoloreds have adapted by nesting in agricultural crops — typically dairy silage fields. Harvest of these crops often coincides with egg laying and hatching, and many tricolor eggs and nests are destroyed during harvests. Recent surveys documented nearly half the entire tricolored population nesting in just two colonies in the Central Valley in dairy silage fields in which thousands of nests containing eggs and hatchlings were mowed down during harvest. An unknown number of tricoloreds are shot each year by rice farmers to protect their crops.

The California Department of Fish and Wildlife and other partners have attempted voluntary measures to save tricolor nests from destruction during crop harvest by making crop purchases or reimbursing farmers for delayed harvest on private agricultural lands where tricolors nest. Unfortunately these efforts have not stopped the decline of the species or prevented destruction of tricolor nests on many dairy farms. For example, in 2011, more than half of all tricolor nests in silage fields were destroyed despite efforts to contact farmers and coordinate buyouts of harvest delays.

The Center for Biological Diversity is a national, nonprofit conservation organization with more than 900,000 members and online activists dedicated to the protection of endangered species and wild places.

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