Replication of a 1970s Study on Domestic Sheep Losses to Predators on Utah's Summer Rangelands

摘要: Lamb losses to predation have historically ranged from 4% 8% in the western United States but most data are over 30 yr old. We repeated a sheep depredation study conducted 1972 through 1975 on Cedar Mountain, Utah, determine how rates changed last three decades. Pastures and herd sizes were similar (1 730 lambs) between our (2006 2007) prior one. Additionally, 40% of ranchers also participated study. During 2006 2007, 5.8% all lambs Mountain lost causes compared 9.5% during 1970s. Predators responsible for 87% verified lamb versus 83% estimated that 4.9% killed by predators 7.9% study, coyotes (Canis latrans Say) 67% depredated lambs, cougars (Felis concolor Linnaeus) 31%, black bears (Ursus americanus Pallas) 2%. 1970s, 98% 2%, 0%. In addition increase cougar kills, other change since 1970s is California condors (Gymnogyps californianus Shaw) begun scavenging carcasses. Our results indicate increasing populations cougars, bears, complicated task protecting predators.