Op Image: Burrowing owls pick a precarious home

A pair of burrowing owls are nesting in a vacant commercial lot at the east end of Davis.
A pair of burrowing owls are nesting in a vacant commercial lot at the east end of Davis. dmorain@sacbee.com

The Western burrowing owl population is on the decline in my neighborhood, sadly.

They’re intriguing critters, especially this time of year when they’re rearing owlets. If you get too close, they’ll fake that their wing is injured, perhaps to draw you away from their offspring, or stand tall, maybe to frighten you by their size. They are diminutive, despite their best efforts.

John McNerney has a particular fondness for the raptors, gained during 14 years working as city of Davis’ wildlife specialist and three years before that as a consultant. Ask him why he thinks the birds are cool and he’ll rattle off facts.

Burrowing owls prefer open fields, not land covered by tall brush, the better to spot coyotes and other skulking predators. They don’t nest beneath trees; hawks perch in the branches and swoop down on their prey, which includes burrowing owls.

They a have symbiotic relationship with ground squirrels, occupying squirrels’ burrows, but also providing the rodents with additional sets of eyes to keep watch for outsiders.

The male’s mating call is not a hoot, but rather a coo, not unlike a wolf whistle, as imitated by McNerney. Mates stick together. Once the female turns broody, however, the male is all but unfriended, though he is welcome to return with offerings of food.

After owls have flown their nests, biologists rummaging through their burrows have found plastic toys and flowers. McNerney said the birds seem to prefer the color red. Perhaps males amass the treasures hoping to persuade females to stay awhile.

They also collect feces of mammals such as dogs. Who knows why? But as the stuff decomposes, it emits warmth. Maybe the smell keeps predators away by masking the owls’ scent. It also attracts insects, a staple, which basically transforms a hole in the ground into a burrow and breakfast.

The Burrowing Owl Preservation Society counted 15 breeding pairs in Yolo County in a recent census, down from 63 in 2007. Pam Nieberg, the society’s treasurer, attributes the decline to loss of habitat because of development. She and others also blame predators, the impact of the drought on their prey, rodent poison, and farmers who have been planting grapes and almonds trees, rather than keeping their land in pasture or row crops.

A few years ago, burrowing owls were common behind the Wildhorse Golf Course in Davis. They’re all but gone. Maybe they became flustered by the activity from a jogging and dog-walking path, the native grass grew too tall, or they succumbed to predators.

McNerney has been paying attention to a nesting pair in a burrow at the east end of Davis. By his count, the birds have produced a brood of five. It’s the second year the birds have chosen the field.

The federal government does not list the burrowing owl, which ranges across California and much of the west, as an endangered or threatened species. But they are protected by state and federal laws. So the owner, a partnership of the Buzz Oates Group of Companies and Ramco Enterprises, cannot develop it without taking care of the owls.

McNerney has suggested that the owners let the brush grow. Once the birds can no longer get a clean view of predators, they will get the hint. A far more costly alternative would be to deed comparable land as burrowing owl habitat.

The birds have reason to become alarmed. The Davis Enterprise detailed disturbing signs in the vicinity of the nest, including BBs, beer cans and cigarette butts. Someone, the paper reported, covered their burrow with rocks. McNerney had a name for them: jerks.

For now, however, the birds survive, poking their heads out of their burrow, and venturing out at dawn and dusk in search of mice, bugs, lizards, maybe snakes or smaller birds, and trying hard to look intimidating when a human lumbers near their turf with a long lens.