ABSTRACT
Conditioned Taste Aversion (CTA) is a unique and powerful form of learning that produces dramatic long-term reduction in the willingness of animals to consume a particular food that has been associated with illness. Since CTA can effectively suppress predatory attack among wolves and other predators that would otherwise kill livestock, it has been proposed as a means of mitigating resistance among agriculturalists to reintroductions of wolves in the U.S. As early as 1974 Carl Gustavson established CTA among captive wolves and coyotes and so suppressed predatory attack upon live sheep and other prey. This was accomplished by simply providing predators that routinely attacked, killed, and consumed sheep with sheep meat baits laced with an undetectable, but illness-inducing substance. Illness lasted about 30 minutes. After several days during which wolves ate their regular diet of dog food, they were deprived of food and then allowed to interact with live, totally defenseless sheep in a large enclosure. During lengthy and repeated trials, predatory attack was suppressed among the hungry predators and so sheep survived the encounter uninjured. Captive studies of foxes, rats, cormorants, hawks, cougars, black bears, and other species have confirmed that a properly applied CTA can produce dramatic and lasting alterations in the willingness of predators to attack specific prey. Field trials in which treated baits are distributed into the wild where predators are most likely to find and consume them have repeatedly produced suppression of predatory attack among a very wide variety of free-ranging predators including coyotes, Ravens, Crows, Raccoons, black bears and Blackbirds. In spite of this very large body of evidence, the U.S. Fish and Wildlife Service and the U. S. Department of Agriculture justify excluding consideration of CTA as a device to control wolf predatory behavior by citing what I consider to be highly flawed studies of their own in which CTA was claimed to have failed. Instead, they have supported the use of much less substantiated and promising approaches to altering wolf predatory behavior. For whatever bureaucratic reasons of their own, these agencies have violated ordinary scientific ethics by rejecting CTA without a legitimate replication of Gustavson’s studies and have violated public trust by publicly misrepresenting CTA. I call for a neutral party with competence in behavioral biology to undertake an entirely open and public replication of Gustavson’s wolf research in so far as it can now be humanely done.