Coyote control challenges ranchers, scientists
JEFF GEARINO Southwest Wyoming bureau | Posted: Tuesday, May 29, 2007 12:00 am
GREEN RIVER - Longtime Lincoln County rancher Truman Julian has been outsmarted by coyotes more times than he can remember.
Julian, who runs about 10,000 head of sheep in southwest Wyoming, said it's hard not to admire the coyote.
"There's nothing on earth more cunning than a coyote," he said.
Coyotes have been huge problem for his sheep herds over the years, prompting him and other producers to try just about every method of predator control that comes along.
"We've tried everything," Julian said during a recent visit to one of his nine sheep herds that were moving up from winter grazing grounds to summer pastures in Sweetwater, Lincoln and Sublette counties.
"I remember one year, they were selling a repellent spray at 50 cents per head that was supposed to keep the coyotes away … so we bought a whole bunch and sprayed them all," Julian said with a laugh.
"Well, what it did was help those coyotes zero in. We had one of our biggest losses ever. I think we lost 30 percent of the lambs that year."
The Wyoming Legislature approved $6 million for predator management in Wyoming last winter, in part to pay for continuing predator control research.
In the past, predatory animal districts had about $550,000 to work with statewide, while the state's Animal Damage Management Board had $230,000.
Some of the money has gone to a handful of unusual coyote-related research projects. The research funds have primarily come from the Wyoming Game and Fish Commission's annual $100,000 allocation to the Animal Damage Management Board.
From computerized fear-provoking devices to toxic mixes of chocolate and coffee extracts, researchers are always looking for new ways to control predators.
John Johnston of the National Wildlife Research Center in Fort Collins, Colo., along with other national researchers, has been experimenting with the use of cocoa and coffee/tea concentrates to poison predator canids including the coyote, while leaving other wildlife unharmed.
The research project expands upon past veterinarian experiments on a range of pets that identified chocolate and caffeine as deadly to dogs, but not to most other animals.
It seems coyotes can't metabolize the chemicals bromine and caffeine.
Johnston is seeking to develop a predator control toxicant from concentrated extracts of the tea and cocoa plants that kills coyotes and other predators, but is virtually nontoxic to humans, environmentally benign and relatively safe for nontarget species.
Research is also continuing on a project investigating the feasibility of delivering male spermicides and a chemical that aborts pregnancies to coyotes, with a goal of cutting birth rates to decrease livestock predation to feed hungry pups.
Other researchers are investigating the development of self-activated delivery mechanisms for oral poison baits that specifically target coyotes. The devices would use some sort of an electro-mechanical approach that reduces or eliminates the threat of bait exposure to nontarget species.
And for several years, University of Wyoming researchers have been evaluating the effectiveness of nonlethal, mechanical and computerized "fear-provoking" devices. The deterrents, also known as "persuader-frightening" devices, has been used successfully on captive coyotes.
Southwest Wyoming bureau reporter Jeff Gearino can be reached at 307-875-5359 or at gearino@tribcsp.com.