Whooo is Saving the Burrowing Owl?

After nearly two years of planning and brainstorming, the San Diego Zoo Institute for Conservation Research is launching a new program focused on burrowing owls and their habitat right here in San Diego County.

Dr. Ron Swaisgood, Director of Applied Animal Ecology at the Institute, has been working with a team of Institute scientists, U.S. Fish & Wildlife Service, California Department of Fish & Game, San Diego Area Governments, San Diego State University (SDSU), and others to craft a new approach to conservation right here in our own backyard. With a new team of Institute researchers headed by postdoctoral researcher Dr. Colleen Lenihan now in place, the team is ready to hit the ground running. And there will be a lot of groundwork, literally, to be done.

In this project, we will start with the ground, and the California ground squirrels that dig in it. First, SDSU researchers, led by Professor Douglas Deutschman and graduate student Sarah McCullough, will prepare the ground by conducting “vegetation manipulation” designed to create the more open grassland habitat favored by ground squirrels and burrowing owls.

Then, Institute researchers will release ground squirrels captured from nearby areas where they are not wanted. While it is true that squirrels can be pests in agricultural areas, they play an extremely valuable role as “ecosystem engineers” in California grasslands. Their burrowing activity creates refuges for a variety of wildlife, including nesting sites for burrowing owls, and their foraging activities keep the vegetation low and more open.

Studies have shown that there is a greater diversity of animal life where squirrels are present than where they are absent. Their rodent relatives, the kangaroo rats, are known to play an instrumental role in maintaining native vegetation, and this may well be true for ground squirrels too. So, give our local squirrels the respect they deserve!

Finally, the Institute-SDSU team will keep returning for years to come, monitoring the effects of their experiment. Different methods will be tested so that we can determine the most optimal strategy for restoring more functional grassland habitat in Southern California, and, we hope, draw in burrowing owls. If this build-it-and-they-will-come approach doesn’t work, we may decide to translocate burrowing owls to these newly “engineered” areas later.

In a second study, the Institute-SDSU team will study a few of the small remaining population of burrowing owls still residing in San Diego County. In addition to more traditional techniques, we plan to place “burrow cams” in their underground nests to observe how they care for their developing chicks. We are hopeful that this research will give us a richer and more detailed picture of their breeding and foraging patterns and will give us new insights into the ecology of this species.

The end goal, of course, is to provide new found knowledge that will aid in future policy and conservation management decisions.

These endearing owls, familiar to and beloved by so many, are in decline throughout their range. We hope that our science-driven approach will help define strategies that can be used regionally to help restore this unique and irreplaceable grassland system that defines much of the West. We are already making plans to launch a second California-wide program examining ecological and genetic factors that may be contributing to the owls’ decline or important for their recovery.

Photos by Gloria Kendall, San Diego Zoo Safari Park