Predator behavior studiedWritten by Christy Martinez
Logan, Utah – An APHIS center in Utah aims to develop efficient and socially acceptable tools to minimize livestock depredations.
The National Wildlife Research Center does this by identifying predator traits that can be exploited, creating more effective means to capture problem animals or to exclude them from areas with livestock.
Research wildlife biologist Stewart Breck, who works at the Center, is involved with researching non-lethal control of large carnivores that interfere with livestock.
“We cover the gamut in dealing with predators,” he begins. “And we have projects around the West with bears, wolves and coyotes in various situations, some urban and some agricultural.”
Their work, which includes a captive 100-coyote facility, involves reproductive control, behavioral research, repellant and lethal toxins.
“Our science is divided into two areas,” he says. “One is learning about the ecology of predators and their impact on livestock and native prey – the basic biology of carnivores.”
The second, he said, is technique-oriented, including trap, toxin and repellant development. “The beauty is meshing the two and developing tools to manage predation to reduce some conflict associated with predators,” he adds.
“We’re interested in cost effectiveness, efficiency and how easy they are to use,” says Breck of his non-lethal work. “There’s a smattering of techniques we’ve worked on, integrating predator biology and human dimensions into tool development. Looking into the future, most work will focus on black bears, wolves and coyotes with cattle and sheep.”
Breck explains there are two ways to classify repellants – primary and secondary.
“The primary repellants try to scare the animals, creating a flight or startle response using scare devices like lights or sounds. The secondary repellant is where you’re inflicting pain or discomfort so they associate a negative experience with a particular area or animal,” he says.
Regarding wolves, Breck says they’re “neophobic,” or afraid of new things, and the Center has capitalized on that to develop repellants.
“We know they’re frequently near livestock, but they’re not necessarily killing or harassing. When that does happen, it’s intermittent and unpredictable,” he notes, adding that because of that it’s hard to proactively manage with scare devices and repellants.
One strategy tried with wolves is “fladry,” which Breck explains as something that looks like a used car lot, with flags waving to catch attention. While it can be effective for small contained areas, he notes wolves will habituate in 30 to 60 days. Because of that, researchers tried electrifying the rope from which the flags hang – an example of primary versus secondary repellant.
A study in Minnesota placed captive wolves adjacent to a herd of deer, separated by a line of fladry. The study compared normal fladry to electric fladry. With the normal faldry, all the wolves crossed the line in one day. Three of the five never crossed the line over a 14-day period with electric fladry.
“The electric fladry was at least 10 times more effective than fladry alone,” says Breck. “These results gave us a lot of hope this would be effective in the field.”
However, a Montana trial two years ago set up various pastures with fladry, while others weren’t protected at all. No wolves came into any of the pastures, which only proved the unpredictable behavior of wolves.
The cost per mile on electric fladry has been evaluated, and producers in the project area have been surveyed. The electric fladry costs about double that of regular fladry, plus maintenance costs. Producers didn’t feel like the fladry stressed livestock, but there wasn’t a lot of consensus as to how well it worked to repel wolves, because there weren’t many wolves in the area to begin with.
“One thing they felt strongly about was that it was too expensive to implement without support,” says Breck, adding he thinks it’s a very effective tool in the right situation, such as a small pasture or calving or lambing areas. “But if producers think it’s too expensive it won’t be used.”
Another device, which Breck refers to as “even less practical,” is a radio-activated guard he calls the Cadillac of scare devices – a complicated box with lights and speakers programmed to emit any sound, such as helicopters or gunfire, when the predators are in the area.
“The wolves wear radio collars and the box goes off when the wolves are close enough,” explains Breck. “This system is very expensive and it doesn’t give protection over a long period.”
“Wolves are very persistent and clever and trying to fool them with scare devices is a lot of work,” says Breck. “They’re effective for a while, but you have limited time. In the right context maybe they are a tool.”
Regarding bears, the Center has assessed damage and managing predation, including translocation as a repellant, which worked 92 out of 94 times in Wisconsin, but hasn’t been successful in Colorado.
“We’re also trying to work with sheep depredation in Utah. We know there’s a critical time period when bears get into sheep, and if we can provide supplemental food during that period we can keep them out of sheep,” says Breck.
Moving on to coyotes, Breck says two studies 30 years apart found individuals were different, but territories were almost exactly the same. “The space use of these packs is really consistent, which we haven’t seen with wolves,” he noted.
Breck acknowledges individual variation within packs of predators, and that some are bold and persistent while others are shy.
“If you’re thinking about using repellants, we know a population of coyotes will be composed of both types, and how they interact with scare devices will be really important. When deciding when to use a repellant, one has to give it a lot of thought,” he says.
“The general message so far is maybe the best bet is to individually lethally remove problem animals,” he adds.
He adds that any non-lethal repellant has to have a variety of sounds, noises and be in the proper context, which is not an open range situation, but maybe at lambing or calving in a small confined area.