Olfactory discrimination of lithium chloride by the coyote ( Canis latrans)

Following illness from 100 g dog food containing 6 g lithium chloride, coyotes ( Canis latrans) were presented with a series of simultaneous olfactory discrimination tests. In the first test the coyotes avoided dog food laced with 6 g lithium chloride, choosing plain dog food on all trials. In the second test the coyotes avoided dog food laced with 6 g sodium chloride, again choosing plain dog food on all trials. When tested with dog foods containing 6 g lithium chloride vs 6 g sodium chloride, the lithium chloride-laced food was avoided on 83% of the trials. Then, in a series of tests with decreasing quantities of lithium chloride in laced dog food vs plain dog food, the coyotes' performance was found to be a linear function of the logarithm of the quantity of lithium chloride in the food. Errorless performance occurred at 1 g lithium chloride and above, 75% correct responding occurred at 50 mg lithium chloride, and chance performance occurred at 3 mg lithium chloride and below. These results indicate that coyotes can form an olfactory aversion to lithium chloride in food, and although they can discriminate lithium chloride from sodium chloride by olfaction, the aversion will generalize to sodium chloride. The results are discussed regarding the aversive conditioning of nongustatory cues by taste mediation and the use of proper dosages of lithium chloride in the control of coyote predation on domestic livestock.