Nestled inside the eave spout of a South Shore business office that overlooks Lake Tahoe is a bird’s nest with three squawking, hissing chicks and an adult.

But it’s no ordinary nest where one may find a Steller’s jay or sparrow family. Instead, the nest is holding a family of barn owls, perhaps the first ones documented in the Lake Tahoe Basin, according to wildlife experts here.

The owl family was discovered about three weeks ago. The owners of the building have asked the Tahoe Daily Tribune not to disclose the site fearing vandalism to the nest.

“My boss was outside the building taking pictures and saw something moving. They looked like owls but I wasn’t sure, so I called Lake Tahoe Wildlife center,” said Janel Morales who works in the building.

A videotape of the nest and birds was made by a Lake Tahoe Wildlife Care volunteer and it was identified as a barn owl by Executive Director Cheryl Millham.

“In all the years we’ve been doing this, we’ve never seen them up here,” Millham said of the bird. “I’m stunned because they live in agricultural areas where there’s barns and lots of mice.”

The barn owl is common in the Carson Valley and on the West Slope. They have a body length of 14 to 20 inches, a 31Ú2-foot wingspan, and weigh anywhere from 8 to 21 ounces, according to the Web site peregrinefund.org.

The owls prefer open lowlands with some trees, including farmlands, plantations, urban areas, various forest types, semi-arid shrub lands and marshes, according to the Web site.

But the Tahoe basin is not a place where one would find the owl, Millham said, mainly because of the extreme seasons and a limited food source.

“They prefer the open fields where they can find mice. We really don’t have that type of habitat up here,” she said.

Where they came from, Millham doesn’t know. The mother could have flown in from the Carson Valley or the West Slope to lay her eggs.

Obviously she’s found some kind of food source, she added.

Deposits fallen from the nest in the owl’s fecal matter show the owls have been eating rodents like chipmunks and small birds, Morales said.

A food source may be Campground by the Lake, which is near the building, both women suggested.

Still, when colder weather sets in at the basin, the birds won’t stick around for very long, Millham said.

“They won’t stay for the winter. They will go where the food is and there is no food up here in winter,” Millham said.