28 December 2011


No, gentle reader, the title does not refer to recipes for stewing, braising, or broiling local members of the genus Canis ~ in North America, including wolves, coyotes, and foxes, not to mention domestic dogs.  Rather, it refers to our increasing understanding of how and to what extent certain canids (especially wolves and coyotes) interbreed to produce viable offspring.  A Scientific American blog post addresses interbreeding with illustrated descriptions of the species and their hybrid offspring.  (An image of a coywolf appears above ~ click to enlarge.)

It is a fascinating and well-told story.  My only quibble is with the author's portraying the wolf as "romantic and charismatic", while the coyote is described as a "pest."  But perhaps that is just how much of our society sees them.  I happen to have high regard for both species.  Each is a top predator, meaning that each has survived over thousands of years by hunting using intelligent tactics.  Further, the coyote has proved to be more adaptable to human intrusion ~ efforts to eradicate coyotes have actually increased their range and numbers.  During my years living in the southern Arizona desert, it was always a thrill to hear coyotes howling at night.  I haven't had the pleasure of hearing wolves yet, a circumstance which stands in need of remedy.

Regular visitors to this forum know that I am a strong proponent for restoring as much of the globe as possible to a natural state, including the healthy presence of native predators.  Conservationists face an uphill battle in persuading ranchers, farmers, hunters, and others that it is not only feasible but desirable to co-exist with all of nature's megafauna in a state of dynamic equilibrium.  

There are success stories, notably in areas where predators like wolves have been re-introduced to parts of their former ranges.  The wolves thrive, and over-populations of prey like elk and deer are winnowed to a healthy size as happened during all the millennia before the arrival of humans. Many human opponents refuse to adapt, going so far as to take the law into their own hands by killing any wolf in sight.  Other former opponents take a more enlightened approach, cooperating with state and federal game agencies and conservation groups to selectively eliminate those predators who repeatedly kill livestock.  Some former opponents, once they realize that there are ways to minimize predation, become defenders of the predators they once reviled.  Some Montana ranchers who live near Yellowstone National park are among them, as documented in the PBS special Wolves in Paradise.

I recently came across an article which describes a potent solution to the conflict.  The experiment took place in Africa, in an effort to dissuade lions from preying on villagers' cattle.  The method is simplicity itself ~ conditioned taste aversion.  Lions were allowed to eat beef which had been "treated with the deworming agent thiabendazole in doses large enough to make them temporarily sick to their stomachs .... After a few meals of treated beef, the lions were once again offered untreated meat."  They refused.

The report states that conditioned taste aversion is "a natural defense mechanism enabling predators to survive encounters with prey with toxic [antipredator] defenses.  When mammalian predators experience nausea after consuming prey with toxic defenses, they form an aversion to the taste and scent of these toxic animals. Long after recovering from the effects of a [sub-lethal] dose of the toxin, predators avoid offending prey wherever they are encountered."  This result has implications for predator-human relations on every continent.

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