Deer populations in Southern Ontario have flourished in recent years, leaving biologists and conservationists scratching their heads over what to do with the "overabundant" deer without killing them.

Deer are a problem in many communities across Canada, where their populations are rising in the absence of natural checks and balances -- predators such as wolves and cougars -- which are no longer found near urban areas.

On Monday, members of the Haudenosaunnee Six Nations began hunting deer on the Dundas Valley Conservation Area. The harvest is part of a 2011 agreement between the Hamilton Conservation Authority and the Haudenosaunee Wildlife and Habitat Authority.

Between November and January, Haudonesaunee Six Nations will be allowed to kill up to 80 deer in the valley - an area the Ministry of Natural Resources says has five times too many deer, Chris Firth-Eagland, HCA Chief Administrative Officer told CTVNews.ca

And while Firth-Eagland said the harvest -- a ministry-recognized traditional activity -- is not a direct attempt to reduce the number of deer, he said aerial surveys conducted by the MNR show a "significant population" of deer.

"According to their statistical analysis and their experiences with the deer population in Southern Ontario, they say there is a tremendous overpopulation," Firth-Eagland said. The MNR estimates the Ontario white-tailed deer population to be at 400,000.

The HCA, meanwhile, is striving for an environment with species diversity, with as "close to a natural balance as feasible."

Deer trample on fragile plants

Deer like to eat trillium: the rare white trillium is a species of flowering plant that is protected in Ontario -- it is illegal to pick the plants on conservation properties.

"In areas where you might expect lots and lots of trillium, perhaps there are very few or none, and that's because that species for instance is a very palatable food for the deer," Firth-Eagland said.

Just five kilometres from the Dundas Valley is the Royal Botanical Gardens, which contains the world's largest collection of lilacs

The RBG is also home to Cootes Paradise Sanctuary, where biologists work to restore plant and animal species into the Niagara Escarpment ecosystem.

Tys Theysmeyer, biologist and head of natural lands at RBG, said large deer pose a challenge for the gardens and the eco-park.

"Anything that's a shrub of any sort is a challenge to grow there," Theysmeyer. "And lilacs are not in any way a preferred food item for the deer, but if they get hungry enough, they will chew on them."

In order to sustain a forest with an understory of wild flowers and shrubs, rich in diversity, the deer population would need to be reduced by two-thirds, Theysmeyer said.

In other areas of the RGB, with meadows and just a few big trees, they see the exact right number of deer.

The RBG isn't actually considering a cull. Instead, biologists are looking to see if they can "change the behaviour of some deer," and steer them to the more open areas.

So far, the RBG has been installing eight-foot tall fences around garden areas. But Theysmeyer said the fences, which are easily destroyed by the deer, have been "an ongoing challenge."

Other solutions the RBG has been looking into range from:

  • Shooting water or sound to frighten the deer
  • Spreading natural predators' urine and feces in the area
  • Installing select feeding stations away from the areas the gardens is trying to protect

"But those, after a bunch of research, proved to be actually remarkably ineffective," Theysmeyer said.

So would a deer cull be the best solution? It would only be effective only in the short-term - unless the culls continued every year.

"(Deer) reproduce just as fast as you can kill them," he said. "So it's a very, very difficult undertaking otherwise, which is why it hasn't been undertaken in this region generally, other than until very recently in nearby areas."

Provincial parks see same problem

Deer Herd Reduction programs in Ontario have been conducted at The Pinery and Rondeau Provincial Parks since 1998, and at Presqu'ile Provincial Park since 2002.

The program aims to "sustainability manage deer populations and to protect the ecological integrity of parks," said Ministry of Natural Resources media relations officer Jolanta Kowalski in an email.

Kowalski said the ministry isn't trying to eliminate deer from the parks. "However, an overabundant deer population can threaten the vegetation and the long-term health and biodiversity of a park," she said.

AnnaMaria Valastro, spokesperson for Peaceful Parks Coalition, has been working to put pressure on the provincial government to reduce the number of deer killings in Ontario. She says deer culls aren't sustainable and only lead to "an endless cycle of killing."

She also disputes the theory of "overabundant" deer, saying overpopulation is biologically impossible. If too many deer are found in one place, they'll naturally die off of starvation or disease, she says.

But for conservationist and biologists working toward species diversity, deer management may be a necessary undertaking.

"It's a complicated adventure, some things are happy with deer and some things are not happy with deer -- depends where one's interest is," Theysmeyer said.