What is Conditioned Taste Aversion?  Conditioned Taste Aversion, or CTA, is a form of behavior modification.  It was discovered in the 1950s by Carl Gustavson and his colleagues when experimenting with radiation avoidance for the Department of Energy.  It was thought that rats, and therefore people, could be trained to avoid radiation because of the effects it caused, primarily nausea.  It was soon discovered that this was not possible, but that there were other applications.  As a side effect, it was noticed that the rats would no longer eat a particular flavor of food once they were irradiated enough to cause nausea.  It was discovered that a relationship existed between the rats not eating the food and the nausea.  Carl Gustavson and his colleagues had discovered that they could create an instinctial aversion in a subject to certain flavors by causing that animal to become sick after eating it.

    Basically, CTA uses an animal's (or person's) natural instincts.  When an animal (or human) eats a food that causes sickness, as say reaction to a toxin or poison, that flavor is then avoided instinctually in the future as a result of a natural defense mechanism.  The body instinctually learns, through necessity, that the flavor in question, is associated with a poison, and forces a 'gut' reaction to that flavor from then on.  In otherwords, it is a subconscious act that causes the avoidance of that flavor due to a previous illness caused as a result of a previous consumption of that flavor.

    It was discovered that this phenomenon could be applied purposefully with wildlife to prevent depredation of livestock.  Carl Gustavson, with the help of his colleagues and his son, Andrew Gustavson, in 1974 tested their theories on coyotes.  The results were startling.  After a single treatment of laced bait of mutton in sheephide, coyotes would not kill or consume sheep, but would kill and consume rabbits, meaning that the coyotes had been successfully been averted to sheep.  These tests were later extended to field trials in Saskatchewan, Canada.  A large test was conducted on 46 large ranches over three years showed an 87% reduction in sheep losses.  Similar results have been seen in other areas, and with other species, including wolves.  Studies have been conducted showing excellent results in Los Angeles with coyotes, in Washington State with coyotes, in Alaska with bears, in Africa with Baboons and wild dogs, and many other success stories.  One would imagine that it would be difficult to argue with such results.