Wolf Management: Non-lethal Control
9. Other Methods
Translocation
Translocation is the capture of wolves and their release in a new area. Translocation has been an accepted method of removing troublesome wolves for several decades in North America. In the northern Rocky Mountains, roughly equal numbers of wolves are translocated annually as are killed for control. Individual translocated wolves are pursued and shot from the air with a dart containing an immobilising drug, then whisked away by helicopter to their new address.
An example of a translocation comes from a management plan of wolves in Alaska and Yukon. A number of wolves from different packs were translocated to the Kenai Peninsula, south of Anchorage. The largest pack consisted of nine wolves, one to four years of age. The new site was chosen for its plentiful wolf prey and the contribution the translocated wolves would make to the genetic diversity of the indigenous wolves, who were fairly inbred on the peninsula. Eighteen translocated wolves were released at three separate sites on the peninsula, all radio collared for monitoring. A month later, one wolf had been shot dead by a hunter, another was found 320 kilometres (200 miles) to the north, and eight of the wolves in the pack of nine were still together living 65 kilometres (40 miles) from their release point.
Advantages & Disadvantages
There are many problems with translocation, in addition to the cost.
Wolves have good homing ability and can find they way home if not moved far enough. Most wolves fail to return home when translocated over 70 kilometres (40 miles), but three wolves translocated in Alaska journeyed homewards between 140 and 280 kilometres (85 to 175 miles) before they were shot (Linnell et al 1996). So translocation is only a proposition for large regions, like North America and Russia. Elsewhere, like human-crowed Europe, it is not an option.
Translocated wolves might be killed as trespassers by already established wolf packs, should there be insufficient space for them to set up new territories. They might disrupt the existing social order of the resident wolves and cause strife. They might spread disease to healthy wolves by taking it from their old range to the new one.
There is no guarantee that translocated wolves will not cause the same trouble, depredation or whatever, in their new home.
Some people object to translocation saying that it is unethical to pick up a wolf, especially one already established somewhere else, and put him in a strange place.
On the whole, the trend for translocation in North America is falling out of custom.
Frightening Devices
Predators tend to avoid or withdraw from unexpected and startling disturbances; combinations of lights and noises have temporarily turned back bears and coyotes from places where they were not wanted. A range of devices with flashing lights and sirens, the modern version of the old scarecrow and rattle, are popular with some farmers and commercial models are on the market. A variety of lights and noises seems to be more effective than a single one and further variation is added by positioning a gadget in different places in a pasture. Portable devices have been developed in the US to make this easy and a timer regulates switching on and off.
Advantages & Disadvantages
Frightening devices are probably most effective in small fields and around penned livestock. Changing the pattern of light or noise might help keep predators away for a while, but after a few days wolves and other predators inevitably ignore them. So the effectiveness of frightening devices is strictly temporary and might be seen as a useless burden or as a useful extra measure at lambing and calving time when livestock are in enclosures. A problem is unacceptable noise and light pollution at night to anyone living within range; wildlife is also likely to be disturbed.
Taste Aversion
In taste aversion, a carcass is treated with an emetic, usually lithium chloride, which induces vomiting and diarrhoea. When a predator eats the meat he will feel ill and the expectation is that he will associate his illness with the meat and not eat it again. More importantly, it is hoped that the predator will make the mental leap from the meat to the living animals and avoid attacking the animals in future.
There is evidence (eg Ternent et al 1999) that taste aversion is effective. However, taste aversion has not been put to widespread use. That wolves and other predators may learn only to avoid treated meat and continue to kill or avoid scavenging carcasses, might be a factor. For a detailed account see Conditioned Taste Aversion.
Another course is to put the emetic on living prey. This has been tried with wolverines in Norway by attaching substances with an efficacious taste and odour to the heads and necks of sheep, with a measure of success for reducing lamb depredation (Landa et al 1993-95).
Artificial Feeding
Artificial (or diversionary) feeding is the provision of supplementary food. Providing food for predators to eat is hoped to reduce depredation.
However, artificial feeding in some circumstances has led to human-predator conflict. Feeding conflict is well documented for black bears and grizzly bears in North American national parks in the 20th century. The bears fed from the large garbage dumps piled up by the parks' authorities, people gathered to watch the bears, fed them more food, bears and people got too close to each other, people were injured and bears were shot or translocated elsewhere. Eventually the dumps were closed and steps were taken to stop people feeding the bears.
If managed poorly artificial feeding could lead wolves to associate food with people. The wolves would lose their fear of people, approach too close, come into physical conflict with people, and sooner or later injure or kill someone. Then the wolves would be shot. Bad publicity for wolves generally.
Restoring Natural Prey
Where there are no natural prey or where they are rare, wolves are forced to rely on domestic livestock. This was the state of affairs for wolves in the American west in the 19th and 20th centuries when the wolf's natural prey was severely reduced by livestock ranchers and hunters. It was also the lot of wolves where they survived in western Europe - in Italy and Spain - and were obliged to feed on small animals, sheep and human garbage.
Killing off all the natural prey of wolves forces them to kill livestock, but restoring their prey does not necessarily prevent depredation. However, restoring the natural prey base of wolves where necessary is an essential step in minimising livestock depredation. Natural prey can be reintroduced where they were extirpated and increased by providing suitable food and habitat for them and by managing hunting and farming more equitably for wildlife.
Electronic Collars
Collars which deliver an electric shock have been used to teach captive wolves to avoid cattle and used on other predators to stop them approaching livestock. When the wearer of a collar approaches a livestock animal an observer delivers the shock by remote control. The expectation is that once predators are suitably trained they will continue to shun livestock and may pass on their behaviour to their offspring.
Only a few individuals can conveniently be caught and trained, however. Once released without their collars, their learned habit of avoiding livestock wears off in the absence of shocks. Livestock themselves could administer the shocks by wearing electronic transmitters. But there is the downside of capturing lots of wild wolves to fit and maintain them with collars.
Rubber Bullets
Rubber bullets are part of the armoury of police forces in several countries. Bullets come in numerous variations from rubber coated ones to rubber capsules. It has been proposed that ranchers in the US should be allowed to shoot rubber bullets at wolves they see posing an immediate threat to grazing livestock. The idea is that the wolves will be stung and shocked without serious physical injury and learn to keep away from livestock and people. Presently, black bears are shot with rubber bullets to stop them loitering where they are not wanted; the bears tend to avoid the place where they were shot, at least for a while.
Advantages & Disadvantages
Rubber bullets are meant to inflict painful but superficial injuries and they are a relatively inexpensive method of control. Livestock producers would not have to wait for wolves to kill their livestock before they can take action. The use of rubber bullets puts ranchers in charge by giving them direct control over wolves.
On the other side of the coin, rubber bullet shooters need proper training. Rubber bullets are not always fired at people in the correct manner and on occasion are lethal. The police and army in Northern Ireland started using rubber bullets in the 1970's and hundreds of people were injured and several killed; eventually the bullets were considered too dangerous and withdrawn from common use. Rubber bullets may be safer than live ammunition but in crowd control, and perhaps for wolf control, are controversial. A seriously injured wolf might be forced to kill domestic stock if he is not up to tackling the more vigorous wild ones.
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