The Role of Gray Wolves in the Modern Yellowstone Region

Anna Campbell (Geology)

Ryan Putt (Natural Resource Conservation)

Kyle Wagner (Building Construction Technologies)

The Big, Bad Wolf has been a cultural symbol of evil long before a young shepherd called wolf, or a girl in a red cape wandered from the path to Grandmother’s house. According to a local Iowa man, Maurice Clements, “wolves kill, slaughter, invade, and destroy.” (Big, Bad, Wolves, 2015, para. 1). The Native Americans described the wolves as violent warriors and thieves in their rituals and legends (Wolf Wars, 2008). In the early 20th century, the negative perception of wolves drove livestock owners to lobby for the extermination of wolves. In 1906, The U.S. Bureau of Biological Survey funded a bounty program to clear cattle grazing ranges of gray wolves (Wolf Wars, 2008). Additionally, the U.S. Congress allocated $125,000 for wolf removal in 1915 (Big, Bad Wolves, 2015, para. 2). The states of Idaho, Wyoming and Montana rarely saw the Gray Wolf after the 1930’s, and the rest of lower forty-eight states of the U.S. saw the complete extirpation of wolves twenty years later (Wolf Wars, 2008). During the 1960’s, increased knowledge of ecosystems led to the passing of the Endangered Species Act (ESA) in 1973. Within a year wolves were included under its protections (Smith, et al., 2004, p. 622). In 1987 the Canadian Grey wolves were reintroduced into the Northwestern United States with the goal of creating a sustainable target population of 300 wolves and at least 30 breeding pairs (Musiani et al., 2005). The reintroduction of wolves was successful, and wolves were removed from the endangered species list in 2009 (Musiani et al., 2010). However the successful reintroduction of wolves rekindled the human-wildlife conflict that spurred the extermination of wolves seventy-five years ago.

The citizens of the Yellowstone region have complained of rampant livestock depredation in the wake of the reintroduction of wolves (e.g. Smith et al., 2004, p. 620). Additionally, there is a negative reaction to the increase in local wolf populations because of the affect the wolves have on the elk and trophy deer populations of the area. Yellowstone residents, unaccustomed to competition for elk in the region, have sought out to defeat their fellow predator, the wolf (Man vs. Wolf, 2013, para. 5). The hunters advocate for extermination of wolves in order to restore the elk and deer populations of the pre-reintroduction era (Big, Bad Wolves, 2015, para. 4). However, the wolves were brought back to the northwestern United States to balance an ecosystem suffering from ungulate overpopulation.

The reintroduction of wolves benefited of the Yellowstone ecosystem.  Wolves are at the top of the Yellowstone food chain, which means their activity and health affect every organism of the levels below them (Wolf Reintroduction, 2011, para. 4). One example is the case of the willow stands.  Without the fear of predation by wolves, elk were free to graze, and depleted the amount of willow trees (Wolf Reintroduction, 2011, para. 8). Beavers use the willow trees that grow along banks of streams for food and construction of their dams (Wolf Reintroduction, 2011, Para 11). Beaver populations hit critically low levels with only one surviving colony left at the time wolves were decided to be reintroduced (Wolf Reintroduction, 2011, Para. 2). Increasing wolf population put increased pressure on elk (Wolf Reintroduction, 2011, Para. 9). The constant threat of predation by wolves decreased over-grazing of vegetation because it caused the elk to be continually on the move (Wolf Reintroduction, 2011, Para. 10). The willow stands were able to rebound, and support the beaver population (Wolf Reintroduction, 2011, Para. 10). Following wolf reintroduction, nine colonies of beavers now exist in Yellowstone (Wolf Reintroduction, 2011, Para. 3). This scenario shows how the wolves actions flow down the trophic levels and positively affect the ecosystem as a whole.  

The negative perception of wolves leads the public to place a disproportionate amount of blame for the depredation of livestock on wolves.  In a 2012 survey of farmers in the Yellowstone region, it was discovered that “wolves killed 675 of the 7 million cattle and sheep” (Dutcher, J. 2013, Para. 8). Wolves account for 0.2% of cattle deaths and 1.5% of sheep deaths nationally each year (Western Wolves, 2009, “Conflicts with Livestock”).  Predation by wolves is a miniscule threat in the big picture of livestock mortalities.  Higher amounts of mortality in cattle include: poisoning, theft, weather events, injury, and birthing complications (Western Wolves, 2009, “What about cattle?”).  The main causes of sheep mortality include: poisoning, weather events, respiratory problems, and digestive problems (Western Wolves, 2009, “Overall sheep deaths”). These statistics show that sheep die approximately 6 times more often from not being able to digest their food then due to wolf predation.  Furthermore, wolves are not even the largest cause of mortality among predators. This is a miniscule number, less than a 1000th of a percent. Other predators ahead of wolves in livestock mortalities include: coyotes, mountain lions, dogs, and bears (Western Wolves, 2009, “Predator depredation deaths”).  Lethal control of these wolves is unnecessary because wolves account for just a tiny sliver (<2%) of livestock deaths annually (Western Wolves, 2009, “What about cattle?”). This recent data proves that wolves play a very minor role in the mortality of livestock, and the negative perception of wolves is unfounded.

Ranchers and farmers in the Yellowstone region advocate for the lethal control of wolves as a primary means of management. It is perceived as the most cost effective, and reliable way to protect livestock. This is not the case. In the research reviewed by Musiani et al.(2010) lethal control of wolves was only observed to prevent attacks for up to a year according to the study by Murray et al. (2010). In fact, killing one wolf shows an increased chance of attacks by 6%, and the killing of 20 wolves doubles the chance of livestock depredation (Jones, 2013, para. 13). These statistics seem counterintuitive, but wolves travel in packs with a sophisticated social system. If the adult wolves are killed, the young wolves will settle in their current area. These leaderless wolves will continue to attack the livestock that their parents died hunting (Jones, 2013, para. 14). Lethal control is also costly. Robert Roman, a resident of Idaho and experienced wolf hunter, spends $1000 per wolf he kills on traps, fuel and time, only receiving $350 per pelt (Jones, 2013, para. 7). Lethal control is an immediate reaction to livestock depredation but does not decrease attack rates and is harmful to the wolf population.

In order to protect the interests of farmers, and maintain balance in the Yellowstone ecosystem, wolves can be proactively managed with different non-lethal approaches. These methods include tracking their seasonal activity, constructing fladry fencing, increased supervision, and livestock protection dogs (LPD).  By educating and spreading awareness to farmers about these simple techniques we can significantly reduce the occurrences of wolf-livestock conflicts.

One method proven to be highly successful includes the use of fladry boundaries (roped boundaries draped with flags) hung around the perimeter of the field. Experiments ran and analyzed by Musiani et al. in 2003 found border structures such as fladry boundaries to be remarkably effective in detouring wolves along the perimeter of sectioned groups of livestock, finding that ”[d]uring two 60-day field trials in which 25-ha cattle pastures were enclosed with fladry, we detected 23 wolf approaches… but there were no crossing and no killings” (p.1543). Thus, proving simple perimeter gating techniques could be an efficient method to immediately reduce livestock depredation.

To assure continuous protection from wolf depredation over longer periods of time, Livestock Protection Dog’s can be used along with the flagged boundaries to account for lapses in the gated perimeter. LPD’s were historically used by farmers to protect their herds from predators. In 2010 studies of LPD’s by Gehring, Landry and VerCauteren examining their effectiveness it was “found that LPD’s reduced predation by 64%, and in one year, 53% of producers with LPD’s had depredation loss reduced to zero” (p. 302) LPD’s are also beneficial to animal behavior, owner’s health, and are economically effective even over long periods of time (Gehring et al., 2010).

The amount of livestock protection needed changes seasonally depending on wolf activity.  In order to best understand these seasonal changes, tracking systems can be put in place to collect data for research over time. Many of these tracking systems are exceptionally proficient and easy to install, maintain, and collect. Gompper et al. (2006) found that stationing baited cameras worked best for detecting animals such as wolves and coyotes. Analysis of this film over time near a farmers grazing patch would allow regional scientists to inform the local community of the seasonal traits of predators. This type of analysis can prove to be important to understanding regional depredation as Mussani et al. found in 2005 examining similarly collected data there were two clear increases in attacks in a particular region, the first during the early spring when calving of livestock generally occurs, and during peak grazing season, with the greatest predation rates occurring in August.  Knowing these peak wolf predation rates is incredibly helpful because farmers will know when they need to ramp up their protection.  One of the non-lethal methods might keep wolves away most of the year, but in peak wolf predation times they may need to incorporate multiple protection methods to keep the wolves at bay.  

By developing the aforementioned techniques into a cohesive method of perimeter protection, balanced with LPD’s, and knowledge of regional tracking data the need for lethal control of wolves can be profoundly reduced.  Lethal control has been shown to be costly and increase the amount of attacks on livestocks, thus non-lethal methods are essential for proper wolf management.  Wolves have a poor reputation amongst the majority of the public, and have paid for it with their lives. With the correct use of these non-lethal protection systems the conflict between wolves and humans will be tremendously reduced. Wolves are immensely important to the North American ecosystem, and conservationists continue to fight to correct the misguided extirpation of gray wolves from the country. By informing the public of the relationship between wolves and the environment, the benign reality of wolf depredation of livestock, and the effectiveness of nonlethal methods of livestock protection, wolves will continue to grow and benefit their natural habitat of Yellowstone.      




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