Central Valley Business Times, February 3, 2015

Federal protection sought for tricolored blackbirds

The Center for Biological Diversity has filed a petition to protect the tricolored blackbird — which once formed massive nesting colonies in the Central Valley — as endangered under the federal Endangered Species Act.
The state recently enacted emergency protections for tricolored blackbirds.

The dramatic decline in the number of the birds has been attributed to destruction of wetlands and native grasslands, shooting, pesticide use, and nest destruction during mowing and harvest of crops used as nesting sites.

“If tricolored blackbirds are going to survive for the long haul, they need the help only the Endangered Species Act can provide. First and foremost, federal protections are needed to halt the ongoing destruction of large nesting colonies, shooting and other threats,” says the Center’s Jeff Miller. “The tricolored blackbird population can’t recover without nest protection, because a small number of breeding colonies can contain most of the entire population. Unless there are immediate protections and limits on killing, this unique bird could go the way of the passenger pigeon.”

Tricoloreds form the largest breeding colonies of any North American land bird, with a single colony often consisting of tens of thousands of birds. The large breeding colonies are 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 alone.

Comprehensive statewide surveys in 2008 found only 395,000 tricolored blackbirds. Tricolored numbers declined to 259,000 in 2011 and only 145,000 were documented last year — the smallest population ever recorded.

The tricolored blackbird is a medium-sized bird that breeds in dense colonies in the Central Valley, coast ranges and in Southern 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 grayish streaks, with a small but distinct reddish shoulder patch. Tricolored blackbirds typically eat insects but will also take grains, snails and small clams.

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