BERKELEY — A burrowing owl was found dead in Cesar Chavez Park over Thanksgiving weekend, worrying those trying to protect the birds.

The corpse was seen on a park bench on Nov. 27, the Sunday after Thanksgiving. Several people reported seeing the body to the Golden Gate Audubon Society, which left messages with park rangers. However, because it was a holiday weekend the body was gone by the time rangers arrived.

Pictures that were taken of the owl corpse appear to show part of its head gone. That could indicate an attack, perhaps by a house cat or off leash dog, according to Golden Gate Audubon Society Executive Director Cindy Margulis. She added that she was speculating and there was no way to know for sure without a necropsy.

“It was awful, it ruined my weekend for sure,” Margulis said

She also said it was possible somebody placed the body on the bench for a ranger to find and retrieve.

Burrowing owls have been coming to the shoreline for several years. This year they have been spotted in both Berkeley and on the Albany Plateau. However, numbers have been declining in recent years. It’s unknown exactly how many come to the shoreline each winter, according to Margulis. They breed in the grasslands and apparently look for food on the shore. Margulis said an owl that had been tagged in Idaho was seen in Berkeley one year.

The birds are 9 to 10 inches tall, approximately the same size as a robin. They breed and roam from the southern prairies in Canada through the western United States all the way down to Southern California. Locally, they use ground squirrel burrows as homes.

It’s not clear if the species has always called the Bay Area home according to Margulis, but it’s quite possible.

“We think so but it’s hard to know because we have done so much to our bay over 100 years,” she said. “There are populations in the Imperial Valley.”

Margulis added that development has squeezed the owl’s nesting habitat. The species is not listed as endangered, but Margulis said conservationists are concerned.

The Golden Gate Audubon Society has been training docents to help protect the owls and also to help the public spot them from a distance. Margulis said habitat has been set aside for the birds, but that it can be difficult to give the owls a protective barrier from domesticated animals.

Cesar Chavez Park has an off-leash area for dogs, but the area near where the owls generally live is supposed to be on-leash. She said sometimes owners don’t follow the rules because they don’t realize the dangers their pets can present.

“They have a quasi-protected area in Cesar Chavez Park but it takes help from the public,” Margulis said. “In any kind of an urban area, people don’t always appreciate the effect pets have on wildlife. They’ll tell you, ‘Fluffy doesn’t chase birds.’”

Margulis added that oftentimes, such a small owl can be extremely stressed if chased by a dog or cat, even if the bird aren’t physically injured.

“The wildlife doesn’t have another choice,” she said. “Either they have those places or we don’t have them, period. It comes down to domestic animals don’t belong off leash in wildlife areas. It’s important that we learn that our pets are not friends to wildlife.”