Richard J. Burns

Secondary hazard of livestock protection collars to skunks and eagles

We evaluated the potential secondary hazard posed by striped skunks (Mephitis mephitis) and golden eagles (Aquila chrysaetos) scavenging carcasses of coyotes (Canis latrans) killed by Livestock Protection Collars (LPCs). These collars are filled with a formulation of Compound 1080 registered with the U.S. Environmental Protection Agency. Skunks and eagles were fed diets containing 4.1 and 7.7 ppm 1080, respectively, for 5 days. Although the treated diets contained 2-3 times the highest concentration of 1080 detected in carcasses of coyotes killed by LPCs, no deaths occurred. Some eagles showed signs of 1080 intoxication including loss of strength and coordination, lethargy, and tremors. Both species reduced consumption of treated diets but resumed normal feeding on untreated diets within a few days

Effect of lithium chloride in coyote pup diet.

Four experiments were aimed at detecting the possible influence of lithium on coyote pup growth and behavior when lithium chloride was fed to the parent coyotes in jackrabbit flesh. In experiment 1, milk samples from two lactating coyotes fed lithium chloride showed a maximum of 12.04 ppm lithium. In experiment 2, hand-raised coyote pups required a concentration of 262 ppm lithium, or more, in bottle fed milk to influence their feeding and weight. In experiment 3, nursing coyote pups showed no lasting influence on weight or nursing behavior when their parents were fed lithium chloride in jackrabbit flesh. In experiment 4, 40-day-old coyote pups showed no lasting effects on body weight or food soliciting behavior after feeding on lithium chloride-treated jackrabbit flesh provided by their parents in the form of regurgitate. Seven months later, the pups showed no avoidance of jackrabbit flesh, nor preference for an alternate food. The results indicated no lasting influence on coyote pup growth or feeding behavior when the pups were fed lithium chloride-contaminated food or milk provided by their parents. The results suggested that placing sheep-flesh baits treated with lithium chloride on ranches in efforts to reduce coyote predation on sheep would cause no lasting, detrimental influence on the pups of adult coyotes that fed on the baits.