The California Fish and Game Commission on Wednesday will consider an emergency listing of the tricolored blackbird as a threatened or endangered species in response to a statewide survey showing its population has plummeted 44% since 2011.
The population crash is alarming and appears to be accelerating, Robert J. Meese, an avian ecologist at UC Davis, said in an interview.
"Listing is definitely warranted – there aren't many places left for this species to make a living," said Meese, who is scheduled to testify before the panel in San Diego. "We've never seen a rate of decline as dramatic as the one we've seen in this species."
The tricolored blackbird was once among the most common birds in California, with vast colonies of the colorful and gregarious species nesting and foraging in marshes and rangelands.
Today, they exist in far smaller numbers in areas including dairy lands, where insects on which they depend are suppressed and nesting grounds are routinely destroyed through the harvesting of grain fields.
A recent survey conducted by Meese with the support of Audubon California and the California Department of Fish and Wildlife counted 145,000 tricolored blackbirds remaining in California, down from 260,000 in 2011.
Already designated a California state species of special concern, the bird could be reduced in number to 50,000 statewide in less than a decade, Meese said.
As part of an effort to save the species, Audubon California and the
“Without the cooperation and commitment of farmers,” Brigid McCormack, executive director of Audubon California, said in a prepared statement, “this bird would be even closer to extinction."
So far, however, that program has failed to stem the decline. Listing would help provide funding for the development and implementation of additional new strategies for stabilizing at-risk colonies.
Some biologists believe, for example, that a ban on shooting red-wing blackbirds in autumn in rice fields would save untold numbers of tricoloreds, which are shot by mistake because the species are nearly identical in appearance and often flock together.
In 2012 alone, 10,878 red-wing blackbirds were reportedly shot in California, nearly all of them in Shasta County, according to the USDA's California Wildlife Services.
Conservationists assume that the number of blackbirds actually shot are higher than the number reported to federal wildlife authorities.
Under the California Endangered Species Act, the commission may list a species when there is an imminent danger. If approved, the bird will be fully protected for six months, after which time the listing may be renewed for another six months.