I recently did a webinar for The Mountain Lion Foundation on the complex issue of bighorn sheep management and mountain lions with a focus on the Southwest United States. Routinely, mountain ranges are cleared of mountain lions for relocation of bighorns, and then predator management is continued in those areas with either increased hunt quotas or agency-paid contractors to protect these small bighorn herds.
It’s a complex subject because bighorns are under continual stress due to diseases from domestic sheep and goats, never able to get a leg up to build a healthy herd. Although bighorns are subject to many diseases, the major respiratory disease, Mycoplasma ovipneumoniae (MOVI), is the ringleader. MOVI weakens the bighorn’s immune system, making them vulnerable to a host of diseases and stressors. Unlike the herd in the Absaroka mountains of Northwest Wyoming where I live that has a metapopulation of over 4000 bighorns in a contiguous protected landscape, desert bighorns live in small herds, on isolated ranges, where connective corridors have been disrupted by domestic animals, roads, and housing developments. Small herds, with weakened genetics, are especially vulnerable to mass die-offs due to MOVI.
Last year I conducted a series of interviews with biologists and agencies and made a trip to Arizona and New Mexico to dig deeper into this issue. Bighorns need our help, but killing lions continuously cannot be the answer. While disease is the lynchpin issue with bighorns, other factors contribute to weakening them, including water, genetic diversity, how to establish metapopulation connectivity, degraded habitat, and of course climate change.
In my latest book, Shadow Landscape, I include an essay that explores these issues and what might be done to help bighorns that would also protect mountain lions. You can read that essay for free on my website blog site. You can also watch the webinar on youtube.
The issue is complex and I encourage everyone who cares about wildlife, bighorns and mountain lions, to watch the webinar and/or read my essay.