One of the joys of being a naturalist is finding the unexpected. That just happened to me as I was driving around Brentwood, CA and saw a pair of burrowing owls. It is a reminder of how adaptable and at the same time fragile is the wildlife that live in and around our sprawling urban areas.
The owls were standing on the sidewalk next to their burrow at the edge of a vacant lot. In the absence of enough grasslands and other natural habitats, disturbed areas and vacant lots have become prime habitat for burrowing owls.
Burrowing owls in California chose sites with available burrows often made by ground squirrels.
The pair was not alone, I counted a total of at least 4 pairs as I scanned the area. The unexpected today is not only that I found burrowing owls, but a small breeding colony. It’s early in the breeding season in California and burrowing owls are just beginning to lay eggs. Females can lay a clutch of up to 11 eggs but more often 4 to 8. Raising a large family takes a lot of energy and the male and female have evolved to take on different roles. The female will sit on the eggs and stay underground for the entire 4-week incubation period, only coming out briefly to feed throughout the day. The male does all the hunting and provides fresh prey daily, primarily insects, small rodents and other vertebrates like small birds, amphibians and reptiles.
Depending on the time of the year, one can often distinguish burrowing owl males from females. Females, are a bit smaller and usually darker with a dirty-looking facial disk (look at the photo above, the male is on the right).
Spring has just begun, and I’ll be observing this small colony during the next few months. I know it isn’t going to be easy for both fledglings and adults.
For starters, they live in an urban area right next to a busy road- collisions with vehicles is one of the main causes of fledgling mortality. In the long-term, it is very likely that the lot in which they are now will be developed in the near future. Burrowing owls are permanent residents in Northern California, so this would mean they’ll have to go somewhere else and take the risk of looking for a new territory- likely another vacant lot or disturbed construction site.
Habitat loss is at the center of the story of burrowing owls across California and the U.S. They have adapted to live around us, but haven’t quite evolved to deal with extensive habitat loss and fragmentation. If you see burrowing owls, consider yourself lucky and just let them be. Also, please report your sighting to the Burrowing Owl Conservation Network based in Berkely, CA - www.burrowingowlconservation.org