Thousand Islands National Park of Canada

Too many deer

Unlike many species monitored at the national park, white-tailed deer are not at risk of disappearing. In fact, deer in the 1000 Islands ecosystem are doing so well that they are overabundant, a serious problem for forest health.
© Parks Canada

One species at no risk of disappearing in the 1000 Islands ecosystem, and indeed across most of Ontario, is the white-tailed deer (Odocoileus virginianus). 

Warmer winters, abundant food sources, and lack of natural predators (wolves and cougars) all contribute to the high concentration of deer in the area.

For the past 14 years, Thousand Islands National Park has been monitoring deer populations. Recent surveys have confirmed that deer are negatively affecting forest health on some of the park islands. Some plant species have been eliminated by deer browsing as overabundant deer populations eat their way across the islands. Future forest health is jeopardized when no young seedlings are allowed to grow and replace older trees.

Human safety is also at risk, as motor vehicle collision data indicates that the number of deer-related vehicle accidents has been rising steadily over the past 20 years.

Long-term deer monitoring is allowing local resource managers to make informed decisions regarding the management of this species. Management options to ensure healthy, sustainable deer populations will be considered in the next year. Local residents can help by not feeding deer.