The Threat of Reintroduced Wolves to Livestock in Yellowstone

The year is 1926.  In Yellowstone National Park, gunshots crack through the air. Then there is silence as the last remaining pack of wolves in the park falls.  For over fifty years, these predators were viewed as just that – wild animals that ate people and livestock – and were hunted to the point of local extinction.  It would take another fifty years for people to realize that something was wrong, out of balance, in the park since the extermination of these iconic carnivores (National Parks Service [NPS], 2015). The animals, the plants, even the very geography of the park changed. Elk overpopulated the region, devouring trees and shrubs. With less plant life, birds were left with no places to nest. Rivers eroded the soil, becoming wider, shallower, and warmer without the shade and roots of the trees. Eventually, only one beaver dam was left, damaging rivers and aquatic life even more. Coyotes flourished without competition from their larger cousins, and decimate small mammal populations, leaving little behind for raptors, foxes, and badgers (Chadwick, 2010). The Yellowstone ecosystem was collapsing. And so from 1995 to 1996, thirty-one wolves were released back into the park with the hopes of restoring balance to this dying ecosystem (NPS, 2015).

The Debate over Wolves in Yellowstone

The reintroduction of wolves into Yellowstone National Park and the Western United States has been debated for many years due to concerns about livestock predation. The public views these wolves in a negative light because farmers, the media, and other outlets often condemn wolves as an evil and unnecessary danger. The issue of livestock predation by wolves arises from many factors, including overlapping habitats. Nelson et al. (2012) explains that the reintroduced wolves prey primarily on the elk population, and often follow elk migration patterns. Elk migrate during different seasons, and so wolves follow them closely, which can sometimes cause them to wander onto farmers’ lands. This unintentional boundary crossing onto farmland can cause major issues for the livestock in the area. This incites a violent response as farmers kill the wolves to protect their livestock (“Helping Ranchers”). Wolf hunting is detrimental to the environment that they were placed into, since the elk populations will not be effectively controlled in the absence of an active wolf population.

Concerns for Livestock

Some of the loudest voices of opposition to the existence of wolves in the Western United States come from local farmers who echo those who eliminated wolves from the region almost one hundred years ago, claiming that wolves threaten their livelihoods by preying upon their livestock. Martin (2014) reports that prices of beef, veal, pork, and poultry all rose over the preceding months, and that officials from the Washington State Fish and Wildlife Department are blaming wolves.  Following the loss of twenty-two sheep to wolf predation, and ineffective non-lethal attempts to deter the wolves, the state authorized the shooting of three local wolves (Martin, 2014). The state decided that it had “no choice but to kill problem wolves” (Martin, 2014, para. 6), just as it did when it authorized the killing of an entire pack in Northeast Washington in 2012.  But wolves actually pose far less of a risk to livestock than many farmers believe.  Fritts et al. (1997) found that no livestock were killed during the first phase of wolf reintroduction in 1995. Furthermore, “Livestock loss due to wolves in the Northern Rockies represents less than 1 percent of all livestock loss” (“The Truth,” 2009, para. 2). While it is understandable for farmers to go to any means necessary to defend their livelihoods, they are in fact battling an insubstantial threat that can be avoided with less violent, more environmentally beneficial methods than simply shooting wolves.

Concerns for Safety

Another concern about having more prevalent wolf populations in the Western United States and particularly Yellowstone National Park is the safety of humans.  With more wolves in the park, the likelihood of tourists crossing paths with these carnivores increases.  According to Yellowstone National Park (2013), when wolves live in areas with frequent encounters with humans, they learn to associate campsites, picnic areas, and other tourist-dense locations as sources of food, which may spark aggressive behavior.  However, Yellowstone National Park (2013) asserts that “No wolf has attacked a human in Yellowstone” (“Wolves”). In fact, there are no known human deaths from wolf attacks in the United States (George, 2006). Yellowstone National Park (2013) also emphasizes safety by cautioning visitors to always maintain safe distances from wildlife and to never feed them, and encourages wildlife viewing from vehicles, through binoculars or camera lenses. While safety concerns are natural and to be expected, the reality is that wolf attacks on humans are extremely rare, and that visitors are informed and educated about how to decrease this probability even further.

Wolves are Essential to the Environment

Wolves benefit the environment through the top-down regulation of surrounding species. As apex predators, the wolves serve to keep the population of primary consumers at a controlled level. Without the presence of wolves, primary consumers overpopulate, causing vegetation levels to rapidly decrease (“8 Big Pros”) . The population of elk and deer rose so dramatically when wolves were extirpated from the region that the forests were stripped of their vegetation (“8 Big Pros”). This cumulative evidence suggests that had wolves not been reintroduced, the ecosystem would have slowly collapsed due to a lack of structure and regulation. Wolves limit plant consumption by hunting herbivores and keeping their populations in check, in addition to eliciting fear responses. Cosier  (2010) explains that even the simple existence of wolves within the park evokes a response in wild ungulates known as an “ecology of fear” (para. 3). Simply put, this refers to the fear that prey animals have of predators that results in their constant migration in order to avoid danger (Cosier, 2010). This fear results in primary consumers eating less vegetation in a concentrated area because they keep moving to protect themselves (Cosier, 2010). The result of this phenomenon, in addition to the direct consumption of herbivores by wolves, is a more balanced ecosystem that will better sustain itself over a longer period of time.

Livestock Can Be Protected with Preventative Measures

Preventative measures are both available and useful for keeping the newly introduced wolf population from interfering with the regional livestock population. With the tremendous development of technology in the time since the wolves were reintroduced, there are various options to monitor the population of wolves. One of the available options is Global Positioning Systems (GPS) that can be attached via collar to the wolves (Cosier, 2010). The use of GPS collars would allow tracking of both individual wolves and family packs to provide an idea of their migration patterns and territory boundaries (“8 Big Pros”). Along with technological prevention there are physical prevention methods that work to form barriers between the livestock pastures and wolf inhabited areas (Musiani, 2003). Fladry barriers are simple rope fences with flags attached that function as an effective wolf deterrent (Musiani, 2003). A simple fladry barrier around pastures would decrease the interaction between wolves and livestock, therefore decreasing livestock predation (Musiani, 2003). By using migration patterns and territory boundaries, researchers and farmers can estimate where the best place for livestock grazing is, and reduce both wolf and livestock deaths.

Resources Are Available to Help Farmers

An array of resources is available for farmers to learn how to implement livestock protection methods into their farming strategies. One crucial resource is the Defenders of Wildlife group, which is a national conservation organization dedicated to the protection of wildlife in North America (“Helping Ranchers”, n.d.). The Defenders of Wildlife will take time to work with interested ranchers to mediate concerns of wolf predation (Barton, 2005). Field technicians will go out to the ranchers’ properties to aid in the reduction of wolf attractants, such as livestock carcasses, or the implementation of security measures, such as guard dogs (“Helping Ranchers”, n.d.). These workers help the ranchers to strategize their farming techniques to reduce the livestock losses due to wolves (Barton, 2005). Non-lethal deterrents are the main focus of the Defenders of Wildlife program because they provide methods of protecting livestock without endangering wolves and, by extension, the environment (“Helping Ranchers”, n.d.). This approach is more beneficial to ranchers than financial compensation for their losses because it allows them to learn first-hand about strategizing their management, aiding them over time (Barton, 2005). Innovative tools, such as guard dogs, electric fencing, and scare devices are brought to the attention of the farmers as options for wolf deterrence (“Helping Ranchers”, n.d.). By providing proactive methods of livestock protection, the Defenders of Wildlife are working to decrease the lethal backlash cast upon the wolves (“Helping Ranchers”, n.d.). By utilizing readily available resources like the Defenders of Wildlife, farmers can make better management decisions and protect their livelihoods without threatening the stability of a fragile ecosystem.

What Should Be Done

Wolves provide an invaluable benefit to the ecosystems of Yellowstone National Park and the Western United States, and so rather than hunting wolves, farmers should protect their livestock by using the ample resources available to them to prevent conflicts with wolves entirely. By protecting livestock through preventative measures, such as physical barriers and migration mapping, and reaching out to farmers about how to use these and other methods to better manage and protect their herds, it will be possible to prevent livestock losses while maintaining a natural balance in the Yellowstone National Park ecosystem.


Wolves are an essential part of their ecosystems, and history has shown the extensive environmental imbalances and damages that occur in their absence.  Without the regulation of the trophic cascade, wild flora and fauna suffer, and the geography of the region itself can be altered.  The reintroduction of wolves to Yellowstone and the Western United States managed to restore much of the area’s environment, and this progress must not be halted by unwarranted concerns for livestock or safety, especially when alternative methods of protecting livestock exist. Habitat mapping, GPS collaring, fladry barriers, and support from organizations such as the Defenders of Wildlife can be used by farmers and wildlife officials to separate livestock from wolves without resorting to violence. Wolves already restored balance to their ecosystem.  All that remains is to restore balance between wolves and humans.


8 big pros and cons of wolf reintroduction. (n.d.). Retrieved from

Barton, M. (2005). Restoration or destruction: the controversy over wolf reintroduction. Journal of Young Investigators. Retrieved from

Beschta, R., & Ripple, W. (2012). Berry-producing shrub characteristics following wolf reintroduction in Yellowstone National Park. Forest Ecology and Management, 276, 132-138. doi:

Chadwick, D. (2010). Wolf wars. National Geographic, 217(3). Retrieved from

Cosier, S. (2010). Reintroducing wolves into national parks could restore ecosystems. Audubon.

Fritts, S., Bangs, E., Fontaine, J., Johnson, M., Philips, M., Koch, E., & Gunson, J. (1997). Planning and implementing a reintroduction of wolves to Yellowstone National Park and central Idaho. Restoration Ecology, 5(1), 7-27. doi: 10.1046/j.1526-100X.1997.09702.x

George, J. (2006). Wolf attack a tragic, cautionary tale. San Francisco Gate, Retrieved from

Helping Ranchers Coexist with Wolves. (n.d.). Retrieved November 23, 2015, from

Martin, G. (2014). Meat prices going up & wolf kill. Retrieved from

Musiani, M., Mamo, C., Boitani, L., Breck, S., Callaghan, C., Gates, C., . . .Volpi, G. (2003). Wolf depredation trends and the use of fladry barriers to protect livestock in western North America. Conservation Biology, 17(6), 1538-1547. doi: 10.1111/j.1523-1739.2003.00063.x

National Parks Service. (2015). Wolf restoration. Retrieved from

Nelson, A. A., Kauffman, M. J., Middelton, A. D., Jimenez, M. D., McWhirter, D. E., Barber, J., Gerow, K. (2012). Elk migration patterns and human activity influence wolf habitat use in the greater Yellowstone ecosystem. Ecological Applications, 22(8), 2293-2307. Retrieved from Web of Science.

The truth about wolves and livestock. (2009). Retrieved from

Yellowstone National Park. (2013). Wildlife. Retrieved from



Leave a Reply