Citing alarmingly steep declines in the species' population, a conservation group is asking the state of California to list the tricolored blackbird as Endangered under the California Endangered Species Act. The group also wants the state to take emergency action to prohibit plowing and harvesting on farmlands where the blackbirds are breeding.

The tricolored blackbird (Agelaius tricolor) breeds in massive colonies of up to 50,000 birds, and especially favors open fields in the Central Valley that have replaced the Valley's formerly extensive floodplain marshes. Agricultural activity such as harvesting crops when the birds are nesting can thus injure or kill tens of thousands of tricolored blackbird adults, eggs and nestlings in a single stroke.



According to the Center for Biological Diversity, which filed the petition to list the blackbird with the California Fish and Game Commission, the birds hit an all-time low count of 145,000 adults in the 2014 breeding season. That's down from almost 400,000 adults in 2008, and untold millions in the 19th century.

The close relative of the much more common red-winged blackbird is mainly restricted to the Central Valley's fields and wetlands, though smaller populations do hang along the coast and in Southern California, and a few outlying populations live in Washington, Oregon, Nevada, and Baja.

The California Fish and Game Code already makes it illegal for farmers (or anyone else) to damage bird nests and eggs in most circumstances, but that law isn't widely enforced. Listing the tricolored blackbird under the state Endangered Species Act would add significant leverage to compel farmers to delay potentially destructive activities until the birds leave the area.

Without such protection, the birds are at the mercy of farmers' goodwill. Earlier this year, Audubon California worked with a Madera County farmer to delay harvest of a crop in his fields that were occupied by tricolored blackbirds. Fortunately, that farmer was sympathetic to the birds, and a delay in his harvest saved as much as a sixth of the state's total population of the blackbirds.

That was a laudable outcome. With protection under the California Endangered Species Act, the birds wouldn't be as dependent on the thoroughgoing goodwill of individual farm operators.

"Biologists and conservationists have warned about widespread losses of tricolored blackbirds and nesting colonies over the past two decades, but state and federal wildlife agencies have failed to take any serious action," said CBD's Jeff Miller. "Unless we want to lose a unique California bird, it's imperative that harvesting and plowing activities on private lands used for tricolor breeding are prohibited or delayed during the upcoming 2015 nesting season -- and that prohibitions on shooting tricolors are enforced."