Nonlethal Predator Management

The original podcast recording from which this article was derived was recorded by the American Sheep Industry Association, featuring speakers Dr. John Tomececk of Texas A&M University and Dan Macon of the University of California Cooperative Extension.

Where there is livestock, especially grazing livestock, there are predators waiting to take advantage of a free and easy meal. While the kneejerk reaction is to eliminate the pressure through lethal means, there are non-lethal methods that can be just as successful. This is especially true if a population of predators lacks boldness and aggression. Generally, eliminating predators does not mean the pressure will go away long-term. Instead, it leaves an opportunity for other predators to take the place of the fallen ones. The new predators have the potential to be more aggressive, which may lead to higher losses. If a relatively well-behaved group of predators exists, managing them through non-lethal methods can be successful.

The role of predators in an environment is important to understanding their management. Predators are part of the native ecosystem that farmers rely on; they consume other animals that eat pasture resources that would otherwise be used for the growth of livestock. Without them, challenges in pasture availability may arise, especially in adverse times such as droughts or years with pasture renovations. That said, during difficult times when prey becomes scarce, otherwise lazy predators may look to your herd or flock for sustenance.

Predators with the largest impact on the largest variety of livestock are coyotes, but there are local differences between predator pressures. Some communities may experience predation by free-roaming dogs, wolves, bobcats, or fox for instance. Ariel predators pose a threat to pastured poultry.

Coyotes are one example of territorial predators, which is part of their instinctual behavior. Their territories are maintained over many years by the same individuals, though they are plastic to the world around them. If the coyote population increases, territories will shrink in size. If resources become limited or hunting/trapping pressure increases, territories will increase. Older animals move around less than younger animals. If the coyotes have a large territory, litters of pups will be larger. Smaller territories produce fewer pups per litter. This example illustrates one of the most highly managed predators in the region, but keep in mind that each predator has a different territorial schema.

What causes predators to attack livestock? Are they more likely to seek out a specific livestock species out if they were raised on it? The answer is: not necessarily. Research has shown that predators raised on a diet of beef, lamb, or goat will not always seek that out as their primary food source. Most predators are not concerned about what they are eating so much as how easy it is to attain. Predators want to keep energy expenditure low when they can. However, if a predator can get to livestock easily, kill easily, and have a decent meal, that can develop into a learned behavior, which will keep them coming back for more. This positive feedback loop may result in them teaching their offspring to kill where there's opportunity. It can therefore be reasoned that predator exclusion and dissuasion practiced at the start of grazing can help keep populations from developing this learned behavior. It is easier to manage predator populations that have a slight aversion to livestock, rather than those which see them as a free meal.

Nonlethal management can include multiple methods: biological, managerial, and physical. More about each of those control measures is outlined below:

Biological:

This method is used to select for more predator resistant herds or flocks. Animals that tend to stomp and stand their ground when being moved by herding dogs and/or people are likely the same animals that will stand up to a predator. Therefore, propagating these genetics in the herd or flock can be useful.

Managerial:

Managerial aspects of predator control are those which the livestock caretaker uses to help reduce the attractiveness of a herd or flock to scavenging predators. This technique is most often used during birthing seasons. If predators are at their peak during certain times of the year, ensuring young stock are born outside of those times may result in higher survivability. Furthermore, keeping a pasture clean of afterbirth and dead stock can help keep advantage-seeking animals at bay.

Physical:

Well maintained net wire fences are the #1 tool producers use to protect their stock. Fencing will not stop all predators, especially if they are determined, but good fences cut down on the number of potential assaults. Fences, combined with other physical dissuasions, can be highly effective in controlling predation.

There are many devices available to help scare off potential animal threats. Dissuading tools such as fox lights and noise makers fall into this category. Alternative options can include flappy arm flailing inflatable tube-people (like the ones sometimes seen in store parking lots) or mannequins dressed in flappy clothes.  Using these tools can result in avoidance of an area, which can ultimately lead to a phenomenon called "disruption", where the predator will change their pattern of behavior by avoiding an area that they sense contains a threat. While these tools have their merit, the key to any of these static dissuasion devices is to rotate their use and understand that they are not a permanent solution.

Livestock guardians can act as dissuaders, too, but instead of staying in the same place like fox lights and noisemakers, they follow the animals around, resulting in a more dynamic dissuasion. A guardian's size may indicate to a smaller predator that they are potentially dangerous, and result in a predator not approaching a herd or flock. The dynamic nature of using an animal as a protector works better for long-term management vs innate objects.

Livestock guardians work by reacting to threatening situations. Dogs in particular have what is known as an escalation strategy, where they may start addressing a threat with barking, then advance to chasing, fighting, and then killing if needed and they are able. Llamas in smaller open systems paddocks can be reasonably effective with canine predators, too. That said, there is a chance in sheep flocks that they will hang out with the slower sheep, inadvertently pointing them out to predators.

Most livestock guardians are in with the herd or flock, which is enclosed by fencing. This results in more barking and posturing at enemies, rather than having the encounter escalate further. The mere presence of livestock guardians can disrupt the ranges of predators. Sometimes the predators will change ranges entirely, but other times, depending on area predator population pressures, may remain within the same range, but purposely not cross paths with the livestock and their guardians.

Properly trained livestock guardians will bond to the herd or flock. They will provide more protection during times of vulnerability, such as lambing, and more general oversight in times when there are less vulnerable individuals around. Some charges will bond with their livestock guardians, too, creating a more powerful dynamic. Those animals with the greatest bonds will receive the most focused attention, but the other members of the herd or flock will still remain under the watchful eye of the guardian.

Alpha predators like bears can be managed with livestock guardians, but the guardians are less effective on them vs beta predators. If experiencing high pressure from these predators, there may need to be a two-pronged approach made, such as penning the sheep up in a more secure pen and having a guard dog present. Another option could be employing a guard dog breed which is specifically bred to work against these larger predators.

In thinking about non-lethal actions livestock caretakers can take against predators, there are many tools at our disposal. The same set of tools will not work for everyone, so using those tools and methods that work for your set of predators, livestock type, and surrounding environment will be the key to developing a robust control program.

To hear the full podcast on the American Sheep Industry website, visit https://soundcloud.com/user-637754734/asi-research-update-predator-management-tools-nonleathal-methods