State Protections Sought For Five Imperiled Populations Of California Burrowing Owls

Last week, conservation groups petitioned the California Fish and Game Commission to protect five imperiled populations of the western burrowing owl under the California Endangered Species Act.

The petition seeks endangered status for burrowing owls in southwestern California, central-western California, and the San Francisco Bay Area, and threatened status for burrowing owls in the Central Valley and southern desert range.

“These fascinating ground-dwelling owls need relief from their homes being bulldozed for irresponsible development,” said Jeff Miller, a senior conservation advocate at the Center for Biological Diversity. “I’ve witnessed the disappearance of burrowing owls from much of California over the past two decades, and it pains me to watch their extinction trajectory. They need immediate protections if we want to keep these owls around to grace our grasslands and open spaces.”

The only owl species that nests and roosts underground, the burrowing owl was formerly widespread in California and commonly nested in grasslands throughout low elevation areas of the state. Burrowing owls have suffered significant habitat loss due to exurban sprawl, conversion of grasslands to agricultural lands, and large-scale wind and solar energy infrastructure. They are also killed by rodenticides and collisions with wind turbines and cars.

The owls rely on burrowing mammals such as ground squirrels to excavate underground burrows for nesting and roosting. Sprawl development removes suitable nesting and foraging habitat, while ground squirrels are routinely eradicated from ranching and agricultural lands.

“When a formerly common species disappears from our landscape, what does it say about the health of our ecosystems? Abundant burrowing owls once brought so much joy to residents of our valley, but development has pushed them to the brink of extinction,” said Shani Kleinhaus with Santa Clara Valley Audubon Society.

Protecting the burrowing owl under the California Endangered Species Act would require state and local agencies to manage threats. That would include ending the state policy of allowing owls to be excluded or removed from lands slated for development, and requiring adequate mitigation for habitat loss. Regional planning efforts, and in some cases direct intervention to boost owl abundance, are needed to prevent the imminent disappearance of burrowing owls from many areas of the state.

“State protections are urgently needed since the environmental review process hasn’t meaningfully protected or conserved burrowing owls,” said Catherine Portman with the Burrowing Owl Preservation Society. “We’ve tried to get mitigation for owl habitat destroyed by scores of development projects in Yolo County, but owl colonies are routinely evicted without requiring habitat protections. For example, 103 acres of prime burrowing owl breeding habitat in Yolo County were developed in 2015 in exchange for only 19.5 acres at a mitigation bank that has never hosted nesting owls.”

State policy allows burrowing owls to be “passively relocated” (excluded) from breeding sites during the non-breeding season to accommodate encroaching development. Many evicted owls don’t survive and rarely do they successfully breed elsewhere. The practice pushes surviving owls onto more fragmented and marginal patches of habitat.

“In mere decades, California has seen the decimation of formerly thriving populations of burrowing owls, once one of the more common birds in California,” said Scott Artis with Urban Bird Foundation. “These unique underground owls, with a life history fine-tuned over millions of years, are now in a fight for survival and need increased state protections without delay.”

Some of the largest remaining burrowing owl populations in the state are facing significant mortality and habitat loss from industrial energy development, with large solar and wind projects killing and displacing scores of burrowing owls in California each year.

“Increased renewable energy development to mitigate climate change impacts should not exacerbate the biodiversity crisis or come at the expense of thriving burrowing owl populations,” said Pamela Flick, California program director with Defenders of Wildlife. “Unfortunately, the existing policy framework has not proven adequate to protect these charismatic owls, so legal protections under the California Endangered Species Act are now urgently needed.”

In addition to the Center for Biological Diversity, the petitioners include Defenders of Wildlife, Burrowing Owl Preservation Society, Santa Clara Valley Audubon Society, Urban Bird Foundation, Central Valley Bird Club, and San Bernardino Valley Audubon Society.