Livestock guard dogs reduce predation on domestic sheep in Colorado

We surveyed the effectiveness of livestock guard dogs for reducing predatio n on domestic sheep in Colorado during 1993. The number of producers using dogs increased from about 25 in 1986 to >159 in 1993. The proportion of she ep with dogs increased from about 7% in 1986 to about 68% in 1993. Producer s with dogs, compared to producers without dogs, lost smaller proportions o f their lambs to predators, especially coyotes (Canis latrans Say), and sma ller proportions of ewes and lambs to black bears (Ursus americanus Pallas) and mountain lions (Felis concolor L.). Overall, producers who did not hav e guard dogs lost 5.9 and 2.1 times greater proportions of lambs to predato rs than producers who had dogs in 1986 and 1993, respectively. Proportions of sheep killed by predators decreased with the number of years that produc ers used guard dogs. Mortalities of ewes to predators regardless of type of operation and lamb mortality on open range decreased more from 1986 to 199 3 for producers who obtained dogs between these years compared to producers who did not have dogs. Of 160 producers using dogs, 84% rated their dogs o verall predator control performance as excellent or goad, 13% as fair, and 3% as poor. More producers (n = 105) indicated effectiveness of their dogs did not change with time, compared to producers (n = 54) indicating effecti veness changed. More producers (n = 35) also indicated their dogs became mo re effective over time compared to producers (n = 19) indicating their dogs became less effective. Estimates provided by 125 producers indicate that t heir 392 dogs saved $891,440 of sheep from predation during 1993. A total o f 154 of 161 (96%) producers recommend use of guard dogs to other producers .