Saturday, February 25, 2017

Burrowing Owl at Mission Bay

"The greatest concentration [of breeding Burrowing Owls] on Otay Mesa is at the mesa's extreme east end, at the southwest base of Otay Mountain, where the scrub is kept very open by frequent fires, started by children in Tijuana tossing burning objects over the international fence to taunt the Border Patrol." --San Diego County Bird Atlas, 2004, by Philip Unitt, page 287.

In that 2004 reference quoted above, Unitt predicted that the Burrowing Owl would be the next breeding species to become extinct in San Diego County. They were widespread, but sparse breeders, back then, and had become much rarer than in the past. The needed habitat is grasslands and open scrub, kept that way by frequent quick fires and protected from other uses during the breeding season. Ironically, eBird data suggests that the only breeding location for these owls that still remains today in the county seems to be Otay Mesa.

Burrowing Owls from inland in western North America migrate south. Several of these birds winter in San Diego County using ground squirrel burrows and road culverts. I've seen them at the Ramona Grasslands Preserve. But often they show up right on the edge of busy coastal residential areas.

One such bird showed up along the San Diego River mouth in late October 2016. It is on the edge of a road/bike path/hiking trail near SeaWorld theme park. It is easy to see and within 10 feet of the road, where it attracts a lot of attention from the hundreds of people passing by daily. It will probably remain through March before migrating back to wherever its summer home is located.

Burrowing Owl
Burrowing Owl amid ice plant. San Diego River mouth, Mission Bay, California. January 1, 2017. Greg Gillson.
Burrowing Owl
Burrowing Owl
Burrowing Owl
Burrowing Owl
Burrowing Owl. Colored pencil. Greg Gillson.