killing wolves to protect cattle
may backfire
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https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=6&cad=rja&uact=8&ved=0ahUKEwid55TUjaXRAhUlxoMKHcidASkQFgg6MAU&url=http%3A%2F%2Fjournals.plos.org%2Fplosone%2Farticle%3Fid%3D10.1371%2Fjournal.pone.0079713&usg=AFQjCNHQDtOs2otGnnSCTglwoqUEU9wnvA&sig2=XogyzSkfeTZSXEG_SsVNvw
Abstract
- Published: November 19, 2013
Abstract
Remedial sport hunting of predators is often used to reduce predator populations and associated complaints and livestock depredations. We assessed the effects of remedial sport hunting on reducing cougar complaints and livestock depredations in Washington from 2005 to 2010 (6 years).
The number of complaints, livestock depredations, cougars harvested, estimated cougar populations, human population and livestock populations were calculated for all 39 counties and 136 GMUs (game management units) in Washington. The data was then analyzed using a negative binomial generalized linear model to test for the expected negative relationship between the number of complaints and depredations in the current year with the number of cougars harvested the previous year.
As expected, we found that complaints and depredations were positively associated with human population, livestock population, and cougar population. However, contrary to expectations we found that complaints and depredations were most strongly associated with cougars harvested the previous year.
The odds of increased complaints and livestock depredations increased dramatically (36 to 240%) with increased cougar harvest. We suggest that increased young male immigration, social disruption of cougar populations, and associated changes in space use by cougars - caused by increased hunting resulted in the increased complaints and livestock depredations. Widespread indiscriminate hunting does not appear to be an effective preventative and remedial method for reducing predator complaints and livestock depredations.
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SMALL FARM SUSTAINABILITY AND COYOTES
Trying to control coyotes is not easy to do, and there is mounting evidence that eradication and wide-scale culling may be counter-productive. The U.C. Davis website Management of Pests of Homes, Structures, People, and Pets notes that population modeling has clearly demonstrated that to effectively impact a local coyote population, annually three-quarters or more must be removed. Even then, if elimination was the goal, this would take decades of intense effort and financial commitment. Toxicants are highly restricted, leg-hold traps are banned in some states and shooting is not safe or legal in many situations. Additionally, as control restrictions and material regulation continues to increase and society’s attitudes toward predators evolve away from control or elimination, reducing coyote populations or slowing the rapidity of range expansion is, from a practical standpoint, impossible.
An article in Audubon Magazine noted that it is conservatively estimated that over 400,000 or more coyotes a year are killed by humans in the United States. That comes down to better than 1,000 coyotes a day or almost a coyote a minute. That said, believe it or not, hunting and trapping pressure may actually enhance the survival and stimulate the range expansion of old-trickster coyote.
Research by Bob Crabtree and Jennifer Sheldon's in and around Yellowstone National Park documented that coyotes incorporate a paradoxical survival mechanism. When heavily hunted by wolves or humans, the number of pups that survive to adulthood can significantly increase. In an unpressured population, only one or two pups in a six-pup litter will live beyond a few months; however, in pressured populations almost all pups survive. This seems to occur because adult removal leaves more food for the pups, ensuring a high survival rate for the majority of the generation to make it to reproductive maturity, resulting in unprecedented population increase.
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