Date: 27th April 2016
Wolf Awareness is currently engaged in two projects, both of which involve research and outreach, and important partnerships:
See our research section to learn more about these projects in detail.
Our priority is providing accurate data on what wolves are eating, and helping people to learn about responsible methods of conflict prevention instead of practicing reactionary and ineffective killing programs.
Please add your support to this project with an on-line donation through Canada Helps: https://www.canadahelps.org/en/charities/wolf-awareness-inc/AlbertaWildCanidCoexistenceProject/
Wolves occur throughout the Northern Hemisphere from the Arctic to as far south as Mexico, Saudi Arabia and India. Once they were abundant over much of North America and Eurasia, although human encroachment and habitat loss have reduced their ranges to much smaller portions of their former habitat. In many such areas, people are livestock producers. However, wolves can kill livestock (i.e. wolf depredation) and this obviously creates conflict with people.
Biologists have spent decades learning about wolf depredations on livestock. Most research indicates that culling wolves does not reduce livestock deaths over time, unless wolves are exterminated (Wallache et al. 2009, Muhly et al. 2010, Harper et al. 2008).
Indeed, there is no evidence to show that indiscriminately killing wolves works as a long-term solution; depredation still occurs in areas that have been practicing lethal control for decades.
Due to historical values and differing social and cultural views, (e.g. urban versus rural) a polarity of opinions exist around wolf management. The spectrum ranges from those who want to protect livestock to those who want to protect wolves. Both objectives could be met simultaneously through working together cooperatively. For example, a large amount of money has been invested within parts of North America to kill wolves in the name of livestock protection. In areas where research has been done, increases in the numbers of wolves killed does not result in decreases of wolf livestock conflict but may actually increase depredations as found in the Eastern Slopes of the Rocky Mountains in southwest Alberta (Muhly et al. 2010). However, when producers record livestock deaths results consistently show that prevention and protecting livestock from wolves reduces conflicts. Prevention of livestock conflict could therefore offer an effective tool for addressing the problem of livestock depredation on a local scale, while fostering nature conservation (Musiani et al. 2004).
As conservation of biodiversity has become a global issue, efforts have been made to restore wolf and other predator populations which are understood to be critical in maintaining healthy ecosystems. Humans have been raising cattle in the Americas for 500 years. Wolves were present on the landscape long before this, but were extirpated in many areas of Alberta and BC through targeted killing during the 1950’s. In recent times, wolves have been more accepted in returning to their former habitat as public perceptions have shifted and wildlife management practices have changed. Ranchers accustomed to living in predator- free landscapes must again learn how to effectively prevent depredation. It is imperative that livestock producers have all the necessary and available tools to effectively coexist with wolves.
Click here to download a copy of our Wolf Awareness Ranchers Guide to prevent livestock losses (2014). We are currently working on updating this and distributing it through our !
Husbandry methods used to avoid depredations are relatively inexpensive. Some of the more commonly used techniques discussed here include: removing dead livestock and attractants, confining or concentrating flocks and herds during periods of vulnerability, establishing a human presence using herders and range riders, livestock guardian dogs, synchronizing birthing to reduce the period of maximum vulnerability, and pasturing young animals in open areas and in close proximity to humans. The type of husbandry used has a large influence on predation when compared to the type of wolf management used or wolf population densities (Musiani, Boitani, & Paquet, 2009).
If a producer can remain “unattractive to wolves” by promptly managing for dead and sick livestock, as well as maintaining a strong human presence, livestock depredation rates will decrease in most areas.
Currently, there is no known place in North America where livestock is the majority of wolf prey (Musiani, Boitani, & Paquet, 2009). This is not always the case in other countries where wolf populations have been all but decimated, such as Europe and Asia. In many of these places, wolves now rely on livestock, small animals and/or garbage as predator prey systems have been lost.
In 2005, research done in Idaho, Montana, and Wyoming indicated that LESS THAN 3% of all livestock mortality was due to wolves, grizzly bears, and black bears combined (Muhly and Musiani 2009). Total livestock losses due to non- predators was at least 89%, with respiratory and digestive problems contributing the most (between 8 – 32%), (Muhly and Musiani 2009).
This study points out that total cattle losses due to wolf depredation in Idaho, Montana, and Wyoming are minor when compared to other causes of death (Muhly & Musiani, 2009).
Where wolves and livestock overlap there will be occasional losses. However, throughout the lifespan of a domestic animal; weather, genetics, feeding, birthing and transportation all pose much greater risks to survival, as indicated in the image to the right.
Issues of safety when wolves and other wild predators are nearby are unwarranted. The real dangers are poison on a landscape, more guns and traps. A larger issue at hand is tolerance.
Compensation programs occur in various parts of North America and cover a wide range of expenses.
Programs sometimes include costs associated with prevention measures. For example, USA-based Defenders of Wildlife compensates for all types of stock killed by predators including livestock guardian dogs. The amount of compensation for loss of an animal or product to a wolf varies from 100% full market value (even if depredation event occurs in spring) to a fraction of this. Sometimes there are general limits to the determined economic value of an animal; however there is seldom a maximum amount a producer can be compensated for.
Most compensation programs will only provide financial aid to producers proven to practice preventative and responsible husbandry methods. Some of these programs will also help to cover costs associated with prevention measures. Others will refund any veterinary costs associated with wolf- livestock conflicts.
It is imperative to determine whether a depredation event is due to predation or scavenging and this will be verified by the compensators at some level. Most provinces have science-based guidelines to help determine whether dead livestock has been killed or scavenged upon, and producers should learn to distinguish the differences themselves in order to protect the evidence needed to support a compensation claim.
The risk of depredation will vary between locations. Depending upon the location and individual situation of the producer, it will usually be necessary to change anti-predation devices and methods frequently as wolves and other predators might become habituated to one single method.
Surveillance and Monitoring: shepherds, herders, and range riders.
Shepherding a flock or herd of any domestic species is an age old tradition used around the globe where predators and livestock share habitat. It is one of the simplest and oldest methods for deterring predators. Human presence can help detect, determine, and alter behaviour patterns of wolves in an area.
The overall approach might involve the following elements:
Surveillance of livestock herds is the most common traditional non-lethal method used by livestock producers in many European countries. However, it is labor-intensive which can be expensive if the producer employs staff to watch over livestock (Musiani, Muhly, Callaghan, & Gates, 2004).
Two possible options to help offset costs if extra labour is employed are:
The keen senses of wolves enable them to recognize when otherwise healthy prey becomes disadvantaged, for example in deep snow. By noting past record keeping, monitoring your herd, and knowing what conditions might increase risk, patrol efforts may be increased during these times.
Managing attractants such as carcasses is critical to avoid attracting predators to an area. Failure to do so has been shown to increase chances of future depredations (Watersheds Messenger Newsletter, Vol. XVII, No. 2, Wood River Wolf Project Workshop 2013). Predators learn where they have received food rewards in the past and are more likely to return to that area. If wolves become conditioned to livestock killing in one area all neighbouring farms may be at risk. Working together to ensure the larger area is attractant free is critical.
Carcass removal programs were more prevalent in western Canada prior to the 2003 outbreak of bovine spongiform encephalopathy, otherwise known as mad cow disease. In some parts of North America, government Fish and Wildlife Agencies will donate the truck and fuel costs.Often funds for these programs are generated through rancher donations, conservation group donations, local taxes, and grants
Constructing a Predator Resistant Fence
In many areas fencing techniques are used effectively to deter predators such as wolves and bears. Electric fences, or combinations of wire mesh and electric fences have proven to be particularly effective (Musiani et al. 2004). However, permanent predator- proof fencing is of limited use when livestock are kept in large enclosures because such fences are costly to build and maintain (Musiani et al. 2004). In such circumstances, or when livestock is semi-nomadic, producers may consider portable electric fencing which can be set up temporarily and powered by solar energy. Another alternative to offset fencing costs would be to combine night penning, which would require only a portion of the pasture to be fenced.
One thing that should be considered when constructing a fence of any type is that it should be visible to wildlife and livestock. Wolves are most active at night and should see the fence before they try to pass through in order to associate the barrier with a visual cue. The visibility can be increased by increasing the thickness of the wire or adding flagging tape.
The bottom of the fence should be less than six inches from the ground. Woven fence can be buried, but it may be just as efficient to ensure that the ground is level. Holes should be filled in. Fences should be checked on a regular basis, because winter ground freezing and thawing can push the posts out of the ground increasing the space between fencing. Electric fencing needs to be maintained to be effective. .
Wolves have been known to jump heights of 5 feet, and thus require a minimum fence height of 1.3 meters.
Simple Electric Fence
Wolves and cougars are jumpers so require a higher fence than bears to be kept out. Combining fladry with electric fencing will help to slow down a wolf to ensure they get a charge (see section on Fladry).
Today there are portable electric fences that can be set up to work within 2 hours, and solar-powered systems that can be installed anywhere there is enough daylight to charge the batteries. Once properly installed, a permanent electric fence can be used for many years. Portable electric fences can be set up quickly and are useful when temporary protection is required, such as during lambing or calving season.
Human safety is not an issue as long as a fence charger is used. This allows for a pulsating charge which allows a person to let go of the wire. This will not do any permanent damage to pets, people, or wildlife but it is unpleasant. You may put up warning signs to alert people that the fence is electric.
Fences will act as a barrier to other wildlife such as deer or elk.
Vegetation must be kept down under electric fences. Vegetation touching the bottom wire will help the wire lose its charge.
Set up electric fence before livestock enters the pasture. This gives wolves time to approach the fence and learn that it is electric, before the desire to penetrate the fence is established.
When fencing on slopes, one will need to consider a loss of height if an animal is approaching a pasture from upslope. Objects such as rocks and fallen logs should be removed from the fence because animals can use these as stepping stones to get over the fence.
Fladry is a simple, inexpensive yet effective method for deterring wolves from entering a pasture. It is a line of flags hung outside a pasture to deter wolves from crossing it and entering the area. Originally, fladry was designed and used to capture wolves. Wolves were funneled into an area and did not want to pass through the visual barrier of the hanging flags.
Fladry fences are easy to produce, cheap and moveable, while being effective for reducing livestock predation on a local and short-term basis. Fladry was found to be effective in deterring captive and wild wolves for up to 60 days (Musiani, et al., 2003). This research was done in smaller areas < 25 ha and humans were patrolling the fence every few days which may have increased its effectiveness.
Turbofladry combines an electric fence with fladry, and can be powered by solar energy. Although more expensive, this type of set up has proven very effective at keeping wolves out of a given area. Initial costs may appear high, but the effectiveness and longevity for preventing depredations should be considered. This is best suited for small pastures.
In the USA turbofladry successfully prevented any livestock losses within one month where 1,000 sheep were in close proximity to denning wolves (Wood River Wolf Project Workshop, 2013).
This is one of the oldest methods used to protect livestock. It has been used in Eurasia for centuries and in some places documented to be used for thousands of years. Livestock guardian dogs have been used for centuries to deter wolves in countries around the world.
Livestock Guardian Dogs (LGDs) must socialize with livestock and bond from a young age (6-8 week pups put in with stock, older than 8-10 weeks passed primary socialization stage The dogs must bond with livestock and not people.
These breeds of dogs are all working dogs. They should be treated with respect and watched cautiously with children and strangers. Training should all be done at a young age with a loving, determined, consistent, and encouraging approach from a dominant leader. They should not be family pets as they may prefer the family over the livestock. These dogs do not herd, only guard livestock. The following breeds are well-known guard dogs though they slightly differ in temperament which is an important factor in considering the best suited dog for your situation. Komondors have been known to bite more people than Pyrenees, Akbash, or Anatolians and Pyrenees have injured less livestock then Komondors, Akbash, or Anatolians (Green & Woodruff, 1988).
The goal of training for a livestock guardian dog is for it to learn that its place is with its flock. Instinct will basically do the rest. Most of the information available about livestock dogs pertains to sheep.
Pups are integrated into the flock usually between 2-3 months. They can be kept in kennels or stalls next to the sheep when left unattended for the first while. Under supervision when the dog is loose amongst its flock, reinforcing the dog to stay with the flock and correcting any negative play behaviour is all of the training needed. This bonding time and the intensity of the bond will be dependent upon the situation. For a full time guard dog a tight bond needing early socialization is necessary. Limited contact with people is also important to keep the dog bonded to the sheep so the dogs are not inclined to bond with humans.
These dogs must be treated like a working dog not a pet. Once the dog is trusted with its flock it can be left alone unsupervised to do its job. This is usually by 6-8 months once the dog reaches maturity.
Livestock numbers – A guard dog can protect anywhere from 20-200 sheep in a flock,( i.e. use 3 – 5 dogs per herd as recommended by the Wood River Wolf Project, USA 2013).
The size of a pasture, number of paddocks, and the distances apart and how dispersed the animals are should be taken into account. Most dogs are used for small pasture rather than large range operations although producers grazing open ranges have also recommended dogs.
Other potential concerns
Factors affecting success
Other Guardian Animals Used: Donkeys and llamas
Donkeys and llamas have a natural hate of canines. However, they can be susceptible to cougar attacks. They have shown to be effective in guarding livestock in some situations. It depends upon the predator species and temperament of the individual donkey or llama. There is not much work done on effectiveness against wolves. They should be placed in stalls beside their flock at first; especially during lambing so the lambs are not stepped on. With donkeys stallions are the most aggressive and may not be suitable as they could become aggressive towards the ewes/cows. Mares and geldings are recommended. Only a couple of donkeys/llamas should be used because they may herd by themselves ignoring the flock. One per flock recommended. Mostly used with small flocks of sheep.
Seasonal Attractants; Calving, Branding and Other “Attractive” Times Calves and other newly born livestock are more susceptible to depredation. Afterbirth can be a strong attractant during the calving or lambing season further increasing risk.
Livestock producers can plan timing, location, and ensure a human presence during birthing. During the calving/lambing season livestock herds are often more dense being kept in close proximity during these times, so when wolf depredations do occur more livestock may be killed at one time.
Many ranchers will calve heifer groups separately from the main herd. These animals are inexperienced as yearlings and more likely to abandon calves, which are likely vulnerable to wolves. Keep cows and heifers together.
Some ranchers have reported success by keeping some bulls as part of the calving herd or introducing other animals with aggressive tendencies such as donkeys or other guardian animals.
Delay the release of newborns onto spring pastures until you can ensure surveillance is provided.
Schedule and manage for a condensed calving season so that human surveillance is easier to accomplish.
Monitor livestock more closely at this time to recognize livestock in vulnerable situations. Increasing human presence will also deter predators.
Remove any biological waste immediately.
Some ranchers believe that yearlings are at a higher risk for depredations. , and There may indeed be behavioural characteristics of yearlings that make them less experienced and more vulnerable to wolves and other predators. Therefore, combining generations may possibly improve herd dynamic defenses.
Some domestic livestock breeds are more aggressive towards predators and have stronger maternal tendencies which leads a more defensive behaviour , leading to a more defensive response. More aggressive breeds will mingle with the rest of the animals and can defend, teach, and toughen up the herd.
Herefords have favourable characteristics and could be introduced into a herd to get a blend of aggression to predators, mothering skills, heartiness, beef value and reproductive success.
Some promising research shows that bonding sheep to cattle may decrease sheep predation (Breitenmoser, Angst, Landry, Breitenmoser- Wursten, Linnell, & Weber, 2005). This practice is most relevant for open range situations. It can also minimize stress during the weaning of sheep, and can help to control the spatial distribution of sheep without fencing.
Understanding seasonal patterns can help improve planning and management, and potentially alleviate conflicts. By monitoring these patterns livestock producers will be more prepared to predict risks and plan for increased prevention and investment of resources if required.
Seasonal patterns reflect livestock calving and grazing practices, as well as seasonal variation in wolf pack energy requirements (Musiani, Muhly, Gates, & Callaghan, 2005). Most wolf-livestock conflict will occur at certain times of the year. For example, occurrences often increase around February to March during wolf breeding season. Some evidence suggests an increase in depredations between April-May when wolf pups are born and energy requirements increase (MacKay, 2005). July-August is another time when wolf-livestock interactions may increase, when pup growth results in more energy demand for the pack, and pups are learning to hunt (MacKay 2005). Biologist Dr. Marco Musiani identified a 3 season pattern in Canada (Alberta ).
Unless these patterns are taken into account, re- occurrences of depredation is likely to continue to occur regardless of wolf culling.
Being able to predict seasonal occurrences will help plan prevention techniques so they can be used efficiently and effectively
It is possible to identify and determine high risk areas on a property and where prevention measures could be focused on (Muhly, Gates, Callaghan, & Musiani, 2010). Knowing and understanding the surrounding terrain also helps to recognize patterns of predation. For example, wolves and cougars often hunt from forested edges. On large properties there may be some areas that pose more of a risk than others being influenced by factors such as distance to a forest edge or slope.
The relative importance of each factor in order to predicting depredation from highest to lowest:
* Note that in the study done in Alberta (Muhly et al. 2010), ranches that practiced wolf culling and/or had yearling cattle herds also had had higher rates of depredations.
initially may be useful at discouraging wolves from remaining in an area.
Margo Supplies Ltd. – High River, Alberta Website:www.margosupplies.com
Email: firstname.lastname@example.org Phone: 403-652-1932
Kane Veterinary Supplies – Edmonton, Alberta Website: www.kanevet.com
Score Construction Ltd. – Revelstoke, BC Website: www.scorefencing.com
Gallagher Animal Management Systems Inc. – Owen Sound, Ontario
Jonco Industries, USA
Website: joncoind.com/sew.html Email: email@example.com
Address: 2501 West Hampton Ave. Milwaukee, Wisconsin USA 53209
Louise Liebenberg and Erik Verstappen Grazerie Farms – High Prairie, Alberta Website: www.grazerie.com
Reports on different breeds of livestock guarding dogs:
Working Dog Web:
A lot of information on guarding dogs with links to other web-pages
Margo Supplies Ltd. – High River, Alberta Website: www.margosupplies.com
Email: firstname.lastname@example.org Phone: 403-652-1932
Kodiak Security Products – Website: www.kodiakcanada.com
Canadian Certified Predator-Friendly Ranchers Louise Liebenberg and Erik Verstappen of Grazerie Farms – High Prairie, Alberta Website: www.grazerie.com
Defenders’ of Wildlife is a USA-based group that has come up with an organized and comprehensive program to reduce livestock losses to wolves by working with various sectors. Defenders’ has published a guide to non-lethal tools and methods to reduce conflicts through addressing root causes: www.defenders.org/resources/publications/program s_and_policy/wildlife_conservation/solutions/livest ock_and_wolves.pdf
More information and links available at www.defenders.org/programs_and_policy/wildlife_ conservation/solutions/coexisting_with_carnivores/ on_your_ranch/index.php
Defenders has also helped reduce tension between Canadian ranchers and wolves. http://www.defenders.org/programs_and_policy/wil dlife_conservation/imperiled_species/wolves/wolf_r ecovery_efforts/canada_wolves/in_the_field.php
An international accredited organization www.predatorfriendly.com
A Large Carnivore Initiative for Europe: http://www.lcie.org/
Carnivore Damage Prevention News http://www.kora.unibe.ch/en/proj/cdpnews/
Flock & Family Guardian Network www.flockguard.org
Social Factors Various sectors and individuals must work to recognize wolves as an important part of an
ecosystem, not something to be liked or disliked. This is essential in order for people to improve their tolerance of wolves.
Note that a deep-rooted social identity often influences tolerances more than actual encounters with wolves and other predators. Many people also view large carnivores as a threat to private property rights and a symbol of government interference.
Perceived risk can be as important as actual experience in shaping attitudes….therefore education is critical for creating a foundation for coexistence. Misperceptions about wolves are not uncommon.
The USA is currently striving to be proactive towards fostering coexistence among livestock producers and wild predators such as wolves by forming partnerships between Defenders of Wildlife, the US Fish and Wildlife Service, the National Wildlife Research Centre, Native American tribes, community conservation groups, and the Livestock Producers Advisory Group.
The following cost comparisons have been made using information gathered by John A Shivik of the US Department of Agriculture in his journal article in BioScience, March 2006 (“Tools for the Edge: What’s New for Conserving Carnivores?”), and through personal communication with wolf biologists, ranchers, and individuals providing electric fence workshops
Livestock Guardian Dogs: Cost estimate $300 – $1000 initial cost, then $500 per year. Could purchase 108 guardian dogs (at $800 each). Duration of effectiveness is approximately the lifespan of guard animal, typically years.
Carcass Removal Programs: Cost estimate 9¢/lb for ruminants where programs occur, with a minimum $75 charge. If the average calf weighs 525 pounds at weaning 1160 calves could have been removed (at $75). If the average cow weighs 1800 lbs, then 537 cows could have been removed. In some parts of North America Fish and Wildlife will donate the truck and fuel costs.
Fladry: Cost estimate $781/km. Could purchase 111.4 km. Duration 60 days
Electric Fencing: Cost estimate -$250 for Super Energizer IV voltmeter- 50 mile range (if off grid $450)
– Grounding plates $17 or rods (rebar)
-rebar posts every 10-12 feet ($600 to $700 per ton)
-stucco wire roll 100 feet $80, or ¼ mile tensile steel $25
Could purchase -348 voltmeters or 5118 grounding plates or 134 tons of rebar posts or 108,750 feet of stucco wire or 870 miles of tensile steel.
Duration of effectiveness would be unlimited as long as fence was properly constructed and maintained.
Turbofladry: Cost estimate $2,303 for the 1st km, then $2,032/km. Could purchase 40 km. Duration of effectiveness is unlimited as long as fence was properly constructed and maintained.
Range Riders: Cost estimate $110/day for 2 months/year is $6,600. In some parts of the US tourists are paying for the opportunity to do this. Could provide range riders for 13 ranches. Duration of effectiveness is ongoing.
Breitenmoser, U., Angst, C., Landry, J. M., Breitenmoser-Wursten, C., Linnell, D. C., & Weber, J. M. (2005). Non-lethal techniques for reducing depredation. In R. Woodroffe, S. Thirgood, & A. Rabinowitz (Eds.), People and Wildlife, Conflict or Coexistence? The Zoological Society of London: Cambridge University Press.
Dorrance, M. J., & Bourne, J. (1980). An evaluation of anti-coyote electric fencing. Journal of Range Management (33), 385-387.
Fritts, S. H.-3. (2003). Wolves: Behavior, Ecology, and Conservation. University of Chicago Press.
Green, J. S., & Woodruff, R. A. (1988). Breed Comparisons and characteristics of use of livestock guarding dogs. Journal of Range Management , 249-251.
Harper, E., William, P. J., Mech, L. D., & Weisberg, S. (2008). Effectiveness of Lethal, Directed Wolf-Depredation Control in Minnesota. . The Journal of Wildlife Management , 72 (3), 778-783.
Lance, N. J., Breck, S. W., Sime, C., Callahan, P., & Shivik, J. A. (2010). Biological, technical, and social aspects of applying electrified fladry for livestock protection from wolves (Canis lupus). Wildlife Research , 37, 708-714.
MacKay, A. (2005). Mitigating Cattle Losses Caused by Wild Predators in British Columbia, A Field Guide for Ranchers. . Agriculture and Agri-Food Canada, [British Columbia Cattleman’s Association], British Columbia Ministry of Agriculture & Lands.
Mech, L.D. and L. Boitani, (Eds.) (2003). Wolves; Behaviour, Ecology, and Conservation. Chicago, USA: University of Chicago Press
Muhly, T., & Musiani, M. (2009). Livestock depredation by wolves and the ranching economy in the Northwestern US. Ecological Economics .
Muhly, T., Gates, C. C., Callaghan, C., & Musiani, M. (2010). In Musiani, Boitani, & Paquet (Eds.), The World of Wolves: new perspectives on ecology, behaviour and management. (pp. 242-273). Calgary: University of Calgary Press.
Musiani, M., Boitani, L., & Paquet, P. (Eds.). (2009). A New Era for Wolves and People. Wolf Recovery, Human Attitudes, and Policy. Calgary: University of Calgary Press.
Musiani, M., Mamo, C., Boitani, L., Callaghan, C., Cormack, G., Mattei, L., et al. (2003). Wolf Depredation Trends and the Use of Fladry Barriers to Protect Livestock in Western North America. Conservation Biology , 1538-1547.
Musiani, M., Muhly, T., Callaghan, C., & Gates, C. (2004). Recovery, conservation, conflicts and legal status of wolves in western North America. in N. Fascione. In A. Delach, & M. Smith (Eds.), Predators and People: From Conflict to Conservation (pp. 51-75). Washington, D.C., USA: Island Press.
Musiani, M., Muhly, T., Gates, C. C., & Callaghan, C. (2005). Seasonality and reoccurrence of depredation and wolf control in western North America. Wildlife Society Bulletin , 33 (3), 876-887.
Shivik, J. A. (2006). “Tools for the Edge: What’s New for Conserving Carnivores?”. BioScience .
Treves, A. (2009). Hunting for large carnivore conservation. Journal of Applied Ecology , 46, 1350-1356.
Wallach A.D., E. R. (2009). More than Mere Numbers: The Impact of Lethal Control on the Social Stability of a Top-Order Predator. PloS ONE , 4 (9): 1-7.