Abstract
San Diego County and the surrounding areas in southern California harbor a wealth of wildlife and people. However, maintaining healthy wildlife populations into the future will require a concerted effort between scientists, managers, and the public. Wildlife health issues often cross disciplinary boundaries, and solutions require that you follow the problems wherever they lead. Ecosystem health is more than just a buzzword—in fact, it requires a broad ecosystem-based approach to identify and ultimately solve problems.
The Wildlife Health Center’s Southern California Program began in the early 1990s as a research study into the cause of bighorn sheep population decline in the Peninsular Mountain Ranges of San Diego and Riverside Counties. Although infectious disease appeared to be the primary cause of mortality, field investigations revealed that mountain lion predation was the major factor limiting bighorn sheep population growth. Lions normally utilize deer as their primary prey, but here we had lions literally driving a bighorn sheep population to near extinction. To further complicate the picture, the conflict between lions and bighorn sheep occurred simultaneously with a sharp increase in lion attacks on people nearby.
Clearly there was more to this wildlife health issue than just the two species (lions and bighorn sheep, or lions and people). To identify, understand, and address the issues in this region, the WHC’s Southern California Program has developed an ecosystem-based approach that encompasses mountain lions, bighorn sheep, deer, people and habitat. The picture that is emerging suggests that the pervasive influence of humans in this region has dramatically altered the system. “Problems,” whether they involve bighorn sheep or lions, have largely been created by humans and human activities. For example, habitat loss (urban development) and modification (fire suppression and catastrophic wildfires) has altered the distribution and abundance of lions, bighorn sheep, and deer. In addition, it has altered the interactions between people and wildlife in ways that pose new problems for people (pets and livestock killed by lions) and wildlife (lions killed for killing domestic animals).
It takes a multidisciplinary, team approach to solve wildlife or ecosystem health problems. The Southern California Program has formed partnerships with state and federal wildlife and wildland agencies, as well as with land trusts and private stakeholders, to develop, fund, and implement solutions. More information on the program is available at http://www.vetmed.ucdavis.edu/whc/scp/default.htm (VIN editor: This link was not accessible as of 2-3-21.)