In his studies of unmolested coyote populations, Bob Crabtree, "has found that when stable long-term residents are killed, younger, transient coyotes take their place. These usurpers do not know how to forage as efficiently and successfully as their predecessors and are much more likely to prey on livestock. Predator control selects for the kind of coyotes and social behavior that is most likely to be a problem to ranchers."(10)

"’The total ADC harvest has apparently had little or no effect on the West’s coyote population,’ wrote G.D. Evans and E.W. Pearson in their six year study of coyotes, published in the Wildlife Society Bulletin in 1980."(10)