Wildlife Services experts keep in touch with the National Wildlife Research Center in Colorado, which studies lethal and non-lethal livestock protection methods. Ranchers are required to tell Spencer when they move their flocks so he can remove active traps from the area. Repellents such as scarecrows, sirens and lights often deter coyotes for several months, but the animals usually adapt and continue to visit the area. Removing dead carcasses from fields may be as effective in reducing coyote predation, but ranchers and field agents often harbor traditional ideas on removing carrion. But a lot of these guys like to leave them at the edge of pastures so coyotes will feed on them and leave the herd alone.
Further misconceptions surround using guard animals such as dogs, llamas and mules.
While such methods appear to be effective in protecting livestock, misinformation and ranchers' resistance to change have prevented their large scale acceptance. When speaking of guard animals, most Wildlife Services agents immediately point to situations in which they didn't work. For every success story, we have a lot of folks that found that it simply cost them more livestock than it ever saved. And dogs are drawn to the same traps, snares and M-44s used to kill coyotes.