"Many people feel that feeding is doing a service to the animals and is essential to their survival," said Brook. "That is sometimes true over the short term, but over the long term there are really important risks to feeding animals."
Brook and his colleagues in Canada and Europe conducted a broad review of the research literature on feeding of wildlife and its implications, from the spread of disease and effect on population densities, to its effectiveness in luring wildlife away from busy roadways and the type of feed to use. Their work is published in the Journal of Wildlife Management.
Brook said the paper offers valuable guidance to conservation officers and management officials, as well as farmers and hunters.
One key finding is that natural forage such as weed-free hay should be used or the supplemental feeding may do more harm than good.
"Over the short term, feeding can and does kill deer and elk due to rumen overload," Brook said. "The animals often can't handle the rich diet provided in winter and feeding them grain and high quality second cut alfalfa can kill them."
Spreading out feeding sites is also important, to avoid large concentrations of animals in any one place which can lead to spreading of disease. This is particularly important in Saskatchewan due to the worrying prevalence of chronic wasting disease, a disease similar to mad cow disease.
"Feeding sites are very high-risk spots for disease transmission," Brook said. "This applies to deer but also potentially to other species such as elk."
While supplementary feeding shows some promise in luring deer away from roadways, it may cause an overabundance of wildlife, which can increase chances of collisions with vehicles. Feeding can also attract wild boar, which are becoming an environmental scourge in Saskatchewan.
"In cases when feeding helps animals survive the winter, this can sometimes cause numbers of elk or deer to increase dramatically," Brook said. "This has associated impacts like wildlife-vehicle collisions, increased crop damage, as well as deer becoming habituated to people and coming right into peoples' farms and yards. As for wild boar, they are much more destructive than any native species."
The researchers' take-away message is that feeding deer and their relatives is not a decision to be taken lightly, and one that should involve community stakeholders.
"How many deer are too many?" Brook said. "It's a complicated question. Are we concerned about disease, vehicle impacts, habitat carrying capacity? What population size—both prey and predator species—can people tolerate? What role do hunters play? These are all questions that need to be considered."
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For more information, contact:
Jennifer Thoma
Media Relations
University of Saskatchewan
306-966-1851
jennifer.thoma@usask.ca
University of Saskatchewan researcher urges caution on winter feeding of wildlife
Feeding deer, whether it is to help them through the winter or keep the animals away from farm grain piles, can have unintended effects, said Ryan Brook, a wildlife and ecosystem specialist at the University of Saskatchewan.