The Western Burrowing Owl (Athene cunicularia hypugaea) is one of the most endearing and beloved of bird species. It was abundant in the Bay Area in the 1920s and was reduced but still commonly seen as recently as the 1990s. Today, it is almost gone in the Bay Area and much reduced in the entire state and elsewhere. It is now a California Species of Special Concern. An estimated 70 per cent of the current population of these owls in California reside in the Imperial Valley in southeast California on the border with Mexico. The only known breeding pair in the Bay Area is in Mountain View Shoreline Park in the South Bay.
There are other populations that breed in the North and Midwest of the United States. A small number of these birds migrate here to spend the winter months in the Bay Area. Their wintering season includes the months from October through March. These winter visitors have been reported in recent years in San Francisco and at several locations in the East Bay: The Albany Plateau, Gilman playing fields, Cesar Chavez Park, Berkeley Meadow, and the Martin Luther King Jr Regional Shoreline in Oakland. A decade ago, observers saw populations of ten or twelve or more Burrowing Owls on any given day in Cesar Chavez Park in the north side “Nature Area,” in the green strip along the northern and northeastern waterfronts, and elsewhere.
Burrowing Owls are unique among owls in that they reside in ground burrows — usually burrows that ground squirrels dug — and do much of their hunting on their feet. They can fly, of course, but commonly use their long legs to run down their prey — typically insects, small birds, mice, lizards, and snakes. They prefer settings with short grass for better ground-level visibility. They also commonly show themselves standing in or near their burrows during the daytime. These characteristics make the Burrowing Owl exceptionally vulnerable to terrestrial predators, including dogs, feral cats, and similar four-footed carnivores.
In Cesar Chavez Park in 2008, an off-leash dog dug up the burrow where one of the owls lived, and the owl left and did not come back. Following that incident, Golden Gate Audubon Society (GGAS) volunteers working with the City of Berkeley installed a temporary fence around part of the northeast corner of the park where there was a concentration of owl-occupied burrows. GGAS refers to the enclosed area as a Wildlife Protective Area.
In 2010-2011, the City of Berkeley in cooperation with the GGAS installed the Open Circle public art project in that area. The art project replaced the temporary protective fence with a permanent decorative fence consisting of six horizontal cables spaced four to eight vertical inches apart, three feet high at the max. The northern third has only five wires and is barely two feet high. The decorative fence offers no effective resistance against dogs or other mammalian predators, and adult humans can easily step over it. No ordinance or regulation prohibits human entry into the fenced area.
On December 2 2016, the Berkeleyside online newspaper published a photo of a dead Burrowing Owl that a runner had found a few days before on a northside bench in Cesar Chavez Park. The carcass showed signs of having been crushed and punctured and partly coated with saliva, but had not been dismembered or partially eaten. The carcass disappeared before wildlife staff could retrieve and analyze it, and has never been found. The injuries to the bird are consistent with attack by a hunting dog.
Since 2007, the City of Berkeley’s Shorebird Nature Center at the Berkeley Marina, in coordination with GGAS, has conducted an annual Burrowing Owl docent training program. Program presenters in September 2017 included Anthony DeCicco of the City of Berkeley’s Shorebird Nature Center, Della Dash for the GGAS Burrowing Owl Docent Program, Karen Rosenbaum and Ben McClinton, veteran docents, David Snippen of the City of Berkeley’s Civic Arts Commission, Sharon Peterson of the Shorebird Nature Center, and Noreen Weeden, GGAS Volunteer Coordinator. Docents visit the protection area, make a careful survey, and if an owl or owls are present, spend an hour or more at the site, perhaps with a spotting scope, showing and explaining the owls to park visitors. Docents record the number of visitors, the number of dogs, on or off leash, other wildlife, and the prevailing weather. Docents are requested to fill out and file extensive paperwork for a database.
During the 2016-2017 winter season, docents spotted at least two and possibly as many as four Burrowing Owls in the Cesar Chavez Park protective area. The first owl was sighted on October 6, 2016, and the last on March 2, 2017. Other sightings occurred on February 11 and 12, 2017. It’s unclear whether the first seen owl was the one killed at the end of November, and there was no way to be certain whether each later sighting represented a different owl or was a repeat sighting of an owl previously reported.
During the 2017-2018 winter season, up to March 6 2018, no owl sightings were reported in the Cesar Chavez Park protective area or anywhere else in the park. Owls may have been present in other park areas with limited visibility, but it’s unlikely.
Three owls were consistently sighted during the same period in the Albany Plateau area. An email list available to owl docents serves as a platform for sharing owl sightings and concerns.
There are four entrances into the Park’s owl protective area. When the area is closed, the decorative fence is stretched across these entrances. The City of Berkeley’s busy Parks and Waterfront staff is responsible for putting up and taking down the fence and for mowing inside the area. (Mowing is important because the owls prefer areas with short or no vegetation.) Opening and closing the fence has not always gone smoothly, as I’ve observed on this blog. In October 2017, within days of being put up, the fence was vandalized at the north and south entry points. Parks staff rebuilt it promptly. In 2015, Parks staff left the fence up all summer, and it was vandalized and practically destroyed in June and July 2015, and not repaired until October. The fence was again left up all summer in 2016, then briefly opened for two weeks for mowing in August, and then closed again.
The fence across the north and south pathways is practically invisible. Unless some marker is hung on it, it poses a hazard to bicyclists.
The nature and location of the decorative fence was negotiated between representatives of GGAS and the City of Berkeley in 2010-11, when the Open Circle art installation was built. It seemed like a good deal at the time, but in retrospect, the arrangement has revealed negatives for both the birds and the public. The decorative fence is worthless protection for the owls against dogs. Extending the fence across the entrance to the Open Circle viewpoint on the south end of the site cuts off the public from an important birding viewpoint and outdoor classroom site that could be used to observe and educate about Burrowing Owls, the Bay, and other wildlife and conservation issues.
I am a sustaining member of the Golden Gate Audubon Society and a current Burrowing Owl docent. I visit the park almost daily. In my opinion, the decorative fence should be reinforced with a taller and tighter barrier, such as four-foot high plastic gardening fence, or better, during the October-March bird visiting season, and the southern end of the fence should be relocated a few yards to the north so that humans can enter the Open Circle outdoor classroom and viewpoint year round. The City should also enact an ordinance prohibiting human entry into the reconfigured fenced area when it is closed during the October-March season, with penalties for violation.
There is an extensive literature and web imagery about the Burrowing Owls. Here is a charming video about a group of owls, produced by the Cornell bird lab. A review of a scholarly treatise on the owls in California is on this site. The Cornell bird lab website, the Audubon Society website, and Wikipedia all have pages on this bird. A thorough report on the owls in Contra Costa County appears here. A web search on Athene cunicularia hypugaea will turn up many more sources.