Brief History of the Bighorn Sheep Ice Age: Ancestor bighorns from Asia migrate into California 1860s – domestic sheep grazing in the Sierra Nevadas begins 1870s – Bighorn populations begin to decline 1876 – California bans sport hunting of bighorns, but population decline persists 1940s – Biologists estimate <400 individuals left in 5 isolated populations

Brief History of the Bighorn Sheep 1972 – Bighorn sheep listed as Endangered under the California Endangered Species Act state bans sport lion hunting first recorded livestock depredation 1978 – 250 bighorn sheep left in 2 isolated populations 1979 – Bighorn translocations begin Early 1980s – Translocations are initially successful - mountain lion population increase observed

Brief History of the Bighorn Sheep Late 1980s – 49 bighorns killed by lions - bighorn sheep abandon winter ranges 1990 – Voters of California pass Proposition 117 1990s – Bighorn populations decline, and decline, until… 1999 – Assembly Bill 560 goes before California legislature

…Where are they now? 1999 – Emergency listing of Bighorn Sheep as Endangered under Federal ESA 2000 – “Permanent” Endangered status 2005 – Recovery plan drafted, but still no Critical Habitat Designation for Bighorn Sheep - Current population: 350 - Major threat: disease from domestic sheep

Photo Credits Slide 1: Bighorn Sheep on Mt. Wilbur in Glacier National Park. Photo courtesy of Kim Keating, USGS. http://nrmsc.usgs.gov/node/433 This image is in the public domain because it contains materials that originally came from the United States Geological Survey, an agency of the United States Department of Interior. Slides 2 and 3: Bighorn Sheep (Male), Near Jasper, Alberta. Copyright © 2007, Alan D. Wilson. http://www.naturespicsonline.com/Nature32/index.htm?5 Used in accordance with Attribution-Share Alike 3.0 Unported as described by Creative Commons in their Public License at http://creativecommons.org/licenses/by-sa/3.0/