Sound Science Bite: October 3. Hunter! Spare That Wolf!

Predator control by culling to reduce livestock loss apparently does not have strong scientific support, or at least that is the conclusion of Adrian Treves and colleagues at the University of Wisconsin in the journal Science, 9 Sep 1916, p. 1080. They canvased the scientific literature on the subject and found, according to them, that all but about 12 studies had flaws. Some objections to their research include the charge that many of the studies weren't that bad and the observation that such studies are extremely difficult in the first place. (This raises the question of how culling can be justified when the studies are admitted to be scientifically non-definitive.)

Of course, it seems like common sense that reducing the number of predators would reduce livestock loss, but there are factors not appreciated that were mentioned in Science, such as females having more offspring or predators extending their range. Also mentioned was one of the "good" studies, by Tom Gehring at Central Michigan University who showed that both wolves and coyotes steered clear of farms patrolled by Great Pyrenees dogs. Gehring is quoted as saying, "you don't hear anybody question that guard dogs work in Michigan anymore."