The baby deer we all stop to watch on the side of the road and call Bambi may be cute, but they are actually posing a huge threat to some of Canada’s most diverse regions.
Within southern British Columbia’s beautiful Douglas Fir and Garry Oak ecosystems, black-tailed deer (Odocoileus hemionus columbianus) populations are exploding and causing a shift in the dynamics of the ecosystem.
According to researchers at the University of British Columbia, herbivores have a huge impact on vegetation structure and bird communities. While oversized deer populations are eating away at iconic plants like camas, fawn lilies and sea blush, they are simultaneously eating away at bird habitat critical to nesting and feeding. Researchers found that these islands with high black-tailed deer populations also had low levels of Rufus hummingbirds and sparrows. These large deer appetites are what lead researchers believe these plants and birds are in danger of local extinction.
To make matters worse, restoration efforts have largely been ineffective. The Galiano Conservancy has attempted to remediate the problem with the introduction and restoration of more native plant species. The deer are completely grazing the plants before they are able to mature and restore the landscape.
The lack of predators in the region have allowed deer populations reach unprecedented numbers, even before Europeans were in North America. In the past, cougars, wolves and hunting by First Nations kept deer populations in check. In the late 1800s, European settlers nearly eliminated cougars and wolves on the Gulf and San Juan Islands, allowing for the explosion in deer populations. Regulations and public sentiment have further reduced deer hunting in more recent times, furthering deer overpopulation. How then can we control deer populations and reverse the effects of over-browsing by deer?
It is not enough to simply reduce deer populations. The damage that has been done to understory vegetation has reached a level where non-native plants will be able to replace native plants. In cases of severe grazing, environmental restoration efforts may need to complement some form of deer management.
Other management options include fertility control or hunting, but neither have much public support. While conservation officers seek solutions, we can spread the word and encourage local stewardship groups to start or continue advocating for deer management solutions.