Pond Boss Forums INTRO Questions & Observations coyotes killing livestock

Although at first many rejected the idea because it was so revolutionary, CTA is now probably supported by more solid empirical evidence than is any other behavioral process. With the sole exception of the wildlife management hierarchy in the United States, there is now no serious controversy within the scientific community concerning whether or not CTA exists as a unique and most powerful form of learning, or whether CTA can quickly produce long-term changes in predatory behavior.

The standard practices of shooting, poisoning or otherwise killing animal �pests� are not very selective, are increasingly resisted by the public, and have often failed to produce long-term reduction in depredation. For example, for more than a century coyotes have been extensively killed in the U.S. but both their range and their populations are actually expanding. Fences and other physical barriers are expensive, difficult to maintain....

...but the most relevant were Gustavson�s captive studies of wolves and coyotes. He demonstrated both would avoid the taste and scent of live prey after recovering from the effects of consuming a meat bait laced with an undetectable dose of an illness-causing substance (Lithium Chloride). In neither of Gustavson�s early studies were there any complex or special inducements to produce the effect. Healthy and unimpaired predators were simply allowed to kill and consume live prey in large enclosures to demonstrate that they were able and willing to engage in normal predatory behavior. Some days later they were given a meat bait with the taste and scent of the live prey that was laced with an undetectable amount of an aversion agent: lamb wool wrapped around a large amount of ground mutton with a moderate amount of Lithium Chloride well mixed with the meat. They were observed to become ill, were allowed to recover for several days on their usual dog food diet, deprived of food until they were very hungry, and then again placed into the enclosure with live prey. Predatory attack was suppressed, resulting in the prey surviving unharmed over post-test durations vastly exceeding predator-prey confrontations in nature. Later, CTA was tested in field trials to reduce coyote predation upon sheep and to induce coyotes to abandon campgrounds where they had been pestering tourists for food (23, 24). In these trials, treated sheep baits were distributed wherever free-ranging coyotes were most likely to find and consume them and changes in reported predation upon sheep were recorded. Although in these field trials other interpretations of the results were possible because it was not possible to make direct observations of predator-prey interactions, the simplest explanation was that CTA was produced and this resulted in the treatment effects that were reported. CTA to control coyote predation upon sheep was again successfully tested in a 3-year field project in Saskatchewan

Prey survive these encounters because predators with CTA respond to them with �disgust� rather than killing and eating them. Long after having recovered from eating a treated sheep bait, captive wolves and coyotes gag and retreat as though punished again by the mere scent of live sheep

Claims made by the U.S. government that CTA failed to �work� were founded on tests of CTA that failed to replicate work reported by Gustavson and others. When the tests reporting �failures� of CTA were first published, it was our opinion that the reported results were perfectly reasonable�given the procedures that were used. The problem was these tests failed to replicate Gustavson�s studies.

They report that predators as different as rats, cormorants , and red foxes quickly formed CTA and avoided referent prey at a distance over many trials; findings very much at odds with their American counterparts. Their work confirmed again that our successes in producing CTA were not merely due to some special talent that only we possessed. The other event was my discovery of a web site maintained by the federal agency with which those reporting �failed� CTA are most consistently associated. This is the National Wildlife Research Center of the U.S. Department of Agriculture. I invite all to read this page. It is: www.aphis.usda.gov/ws/nwrc/flavor.htm. It is anonymous and cites no published evidence for its many claims. Among these are the claims that CTA somehow does not suppress predatory attack and so cannot produce beneficial effects in a cost-effective manner and that CTA is too sensitive to �procedural variations�. These amazing assertions contradict a very large body of scientific evidence (for a few examples: 5, 6, 12, 13, 14, 15, 16, 26, 27, 28, 29, 30, 31, 33, 35, 43). Beyond its falsehoods, the web site seems to me to serve no purpose other than to try to extinguish, in the strongest possible language, any further discussion on the use of CTA. Thus, the rumors I have ignored for many years now seem to have been publicly confirmed for the first time by the tone and content of this web site. That is, it appears that resistance to CTA within the American wildlife management hierarchy indeed is, like CTA itself, more a matter of the gut than of reason.