California Drought Crushes Tricolored Blackbird Population

California's dry spell is exacerbating an existing decline in the local blackbird population. 

Editor's Note: This is the second of three short profiles explaining how the California drought is negatively impacting birds in the area.

The drought in California continues to worsen—over 50 percent of the state is experiencing exceptional drought conditions, the United States Drought Monitor announced last week. This is particularly troublesome for the Tricolored Blackbird. One of the last colonial bird species left in the United States, the current drought makes the species' future look grimmer than ever before.

Like the carrier pigeon from last century, tricolored blackbirds were once so numerous that they would black out the sky when a flock of thousands took flight. Known for their bright red-and-white wing patch, the species is unique to California. Now the conversion of wetland habitat into agricultural land and overhunting has made the population, formerly in the millions, take a nosedive.

In just the last three years, there has been a 44 percent population decrease, dropping from nearly 290,000 individuals down to 145,135 birds. "It typically used to nest in wetlands," says Daniela Ogden, marketing and communications manager for Audubon California, "but the natural habitat are gone."

Instead, the stranded birds flocked to nature refuges and agricultural fields. But water has become a limited commodity, transforming much of California's Central Valley into desiccated firetraps. Wheat fields no longer offer reliable food sources for the Tricolored Blackbirds, as the drought hurts crop yields. 

The birds' problems don't end with finding a place to nest. Even when they can find a decent field to raise little fledglings, Tricolored Blackbirds face another issue: Breeding season coincides with the harvest schedule. The birds are usually packed together in large groups, so a big harvesting machine mowing through is bad news. "In 10 minutes, a quarter of the population can be killed," Ogden says.

Experts fear that one year of poor breeding success could drastically affect the struggling population.

Recently, Audubon California partnered with the Natural Resources Conservation Service and the U.S. Fish & Wildlife Service to strike agreements with farmers to delay harvests and allow the young birds to fledge. Many farmers have agreed to work with them to find an acceptable solution. "They say it's the right thing to do," says Ogden.

Meanwhile the drought continues and all the Tricolored Blackbird can do is soldier on—hoping for as few casualties as possible.