(March 1, 2008)  Predation has a significant impact on the profitability of sheep operations. Each region of the country has unique predator issues and methods in which to deal with those issues. One organization that works to combat the effects of predation on sheep producers’ bottom line is the Wildlife Services’ (WS) National Wildlife Research Center (NWRC) at the Logan Field Station in Utah.

“Predation is a frustrating topic,” said DA Harral, American Sheep Industry Association executive board member, when introducing John Shivik, Ph.D., supervisory research wildlife biologist at the NWRC, to a room packed full of producers during the ASI convention. “But, we (sheep producers) wouldn’t be here if it weren’t for the cooperative effort of those working at Wildlife Services.”

During his presentation, Shivik went into some detail about two of the programs at the field station with the goal of identifying, developing and evaluating improved technologies and tools, especially non-lethal methods, for managing predation.

In the first project, researchers are documenting the impacts, developing control strategies and applying knowledge of predator behavior and demographics for the protection of livestock and natural resources. The second project deals with improving technologies and non-lethal techniques for managing predation.

Wolf Predation
From the research Shivik and his team have done on wolves, they have derived some important conclusions. He said that even though wolf predation is often intermittent and unpredictable, wolves are frequently present near livestock which could potentially cause them to panic and become stressed. Due to the fact that killing of livestock by wolves is so erratic, he said that proactive methods may be less efficient in dealing with them; instead, it is important to be strategic when dealing with problem wolves.

One method the research team is looking into to assist with both wolf and coyote predation is fladry, which is essentially a line mounted along a fence or rope of suspended strips of fabric that flap in the breeze. Fladry has been utilized to funnel predators to a specific area and also to keep them out of a certain area. In addition, the researchers electrified the fladry and are currently conducting a survey of producers who have utilized this procedure in their operations.

Although electrified fladry does have its place in helping deter predators, Shivik said that eventually the wolves and coyotes will figure it out because “they kill for a living.”

Bear Predation
Shivik went on to discuss some of the successes and challenges his organization is having with bears. Because NWRC also feels the pressure from bear hunters, they have been working with some problem bears on an individual basis by relocating them to other areas. One specific study being conducted on this method’s effectiveness is being done in Wisconsin.

By identifying individual nuisance bears using genetic sampling, they relocate them to another part of the state and are monitoring them to determine if the bears return to their original habitat.

“Wildlife Services’ bear translocation work in Wisconsin seems to be working,” explained Shivik, as only two of the 94 bears analyzed thus far have returned to where they were captured.

Other methods in dealing with problem bears the researchers have examined is food aversion conditioning as a repellent and supplemental feeding of bears to reduce sheep depredation. Unfortunately, Shivik said that preliminary results indicate that aversive conditioning hasn’t been successful and the supplemental feeding method is not working either because “we need to find an alternative food that is as attractive as sheep.”

Coyote Predation
Sheep producers all across the United States are now having coyote problems, no longer is it only an issue for those located in the vast open spaces of the West. Because of this, researchers at NWRC spend a great deal of time studying coyotes.

In a study spanning 25 years, NWRC researchers examined coyote movements and determined that they predictably use the same places every year which means proactive methods of controlling them can work to a producer’s advantage, which is in contrast to the wolf.

In addition to fladry, programmable light and sound repellents and trapping devices have been studied to limit predation by coyotes.

In the light and sound study, researchers conducted nighttime trials using light, sound and light and sound to see which method is most effective. They found that sound is less effective than light; however, individual variation within the predators play a significant role.

“Individual variation is why we continue to produce new methods,” explained Shivik, “because no one method is always perfect and the multiple options help Wildlife Services provide better service to livestock producers.”

An age-old method of managing predators has been trapping, but as of late, WS is being pressured by animal rights activists to stop using the devices. Because of this, WS researchers are required to monitor the efficiency (number of coyote captures per device divided by the number of potential coyote captures) and selectivity (number of coyote captures divided by the total number of animals captured) of the trap and the injuries to the animal associated with it.

Based on these measurements, Shivik said they have determined the collarum powered neck snare to be very selective for coyotes and moderately efficient and the soft-catch trap to be very efficient in catching coyotes however it’s only moderately selective. In addition, the cage trap was found to be non-efficient and non-selective and the WS (Turman) snare to be only moderately efficient and selective.

Chocolate Poisoning
A new study being conducted at NWRC is developing a predator toxicant that is:

1. toxic to predatory canids;
2. safe to humans and non-target wildlife;
3. useful in urban and rural environments; and
4. more socially acceptable than cyanide
    or compound 1080.

With this goal in mind and reports published about chocolate toxicity in dogs, researchers tested a chocolate mimic for killing coyotes. In this study, theobromine and caffeine were combined in proportion observed in chocolate and mixed with lard and offered to coyotes. They discovered that the mixture induces a fairly rapid mortality rate and only minimal adverse pre-mortality symptoms were observed.

In a more recent study, researchers were testing the effectiveness of a delivery device for this toxicant. Researchers utilized a clod containing the theobromine/caffeine mixture with a meat-based reward to attract the coyote. Based on the DNA analyses of the clods in the study, 94 percent of the animals that ate it were coyotes, which means there is a great deal of selectivity; however, in another simulated field test study, results revealed the overall mortality was 64 percent. Because of this result, Shivik said the delivery method needs to be revisited.

There is work being done to register the theobromine/caffeine mixture with the Environmental Protection Agency (EPA); however, much more work and studies are required before this occurs. The anticipated date of registration is December 2011.

When asked how good are the chances this toxicant will be approved, Bill Clay, deputy administrator for WS, said that he believes they have a good chance of getting it registered with EPA.

“On a scale of one to 10, I’d say a 10.”