When people think of black bears, they think of Northern Canada and deep forests. These majestic mammals are a symbol of the great outdoors. Anyone who has ever camped in one of Ontario’s provincial parks is informed of their presence and the precautions to take to avoid interaction. In urban areas, it is uncommon to see black bears, and it is presumed that they only live on the Canadian shield. The densest populations of black bears are around the Canadian Shield, averaging 25-28 bears/100km² (MNRF). In recent studies, however, it was found that black bears will migrate when they have reached sexual maturity and when resources are scarce. With more extreme cases of climate change, wildfires, and human development, we could see more in Southern Ontario. All of these factors contribute to scarcer resources available for black bears to prepare for them for hibernation season, and could force them to migrate considerable distances to find plentiful food sources.

Climate Change and Pathogens

Black bears are generalist, opportunistic, omnivores. Their diet generally consists of berries, insects, grasses, roots, and nuts (from mast trees such as American Beech or Oak). They will also feed on fish and mammals. With more extreme fluctuations in climate during growing season, it can have an impact on the availability of the essential foods black bears eat to survive. Increased temperatures in lakes and rivers can create unsuitable habitat for spawning fish that the black bears would feed on. A season that is too wet or too dry can affect the production of berries within a forest – and temperatures outside of the native plants threshold can throw off its ability to photosynthesize or to come out of winter dormancy. With these climatic stressors allows disease and pests to move in. Beach Bark Disease, Gypsy Moth, White Pine Blister Rust and Armillaria root rot are a few of the diseases and insects killing off the mast trees Black Bears rely on.

Wildfires

An increase in pathogens means more dead wood in our forests, and, ultimately, increases the chance of forest fires. Due to the drought like conditions across Ontario, this has caused many forest fires this season. The forest fires have burned over 100,000 hectares of forest, and this number continues to grow. As a result, this leads to a lack of available food sources and unsuitable denning habitat for black bears and other wildlife. Unfortunately, the areas that are being impacted the most in Ontario by the fires are also the areas where black bear populations are the densest (Canadian Shield population’s average 25-28 bears/100km²). Forest fires could lead to increased sightings in Southern Ontario due to bears migrating to safer habitat and abundance of calories. If there is enough food in the bush, the bears will stay in the bush. If not, they will travel elsewhere. And why wouldn’t they travel south, especially since humans offer food – whether intentionally or not – and protection in our forested areas.

Shows the wildfires across the province. The fire symbols in gray represent fires that have been put out, and the symbols in red indicate fires that are still burning. This interactive map is available to view at www.gisapplication.lrc. gov.on.ca/ ForestFireInformationMap (Retrieved August 27, 2018)

Shows the density of black bears throughout the province. When compared to Figure 1, it is easy to see that the densest populations of black bears are overlapping where the wildfires are.(Retrieved from Ministry of Natural Resources and Forestry, 2014)

Human Influence

The ability of black bears to adjust their diet to the circumstances has enabled them to persist not only in a diversity of habitat types, but also in highly fragmented forested areas in proximity to humans. While humans continue to develop natural lands, build roads, and expand cities, conservationists are also improving and connecting natural corridors for wildlife. This allows black bears to travel easily while migrating and leads directly to more urban landscapes. Due to their generalist food habits, black bears are readily attracted to many human sources of foods, such as garbage, agricultural crops, apiaries, and sometimes livestock, especially when their preferred wild foods are scarce.  American black bears may migrate considerable distances (up to 200 km) to find more abundant food sources, especially in late summer and fall, prior to hibernation. And once they find suitable habitat, they may not migrate again until they feel it is mandatory. This means that once black bears show up in our cities, they may never leave.

 Occurrences

Could we see a rise in black bears in Southern Ontario? In 2018 alone, there have been multiple sightings of black bears reported already in populated areas. There have been a few around the Barrie region and some from Huron County. Just a few years ago, black bears were spotted even closer to home, in Halton Region. In Burlington, there was a black bear spotted and tracked in a residential area near Mountainside Park. This bear was unfortunately shot and killed, due to “no other alternative” according to the police officer on duty. Historically, habitat loss and unregulated hunting practises led to the extirpation of Black Bears in the early 1900s. Will the populations take a hit and see history repeat itself with black bears on the species at risk list in the near future? Without proper planning and foresight of what could happen as a result of environmental disturbances, wildfires and certain anthropogenic influences, this could be a likely outcome.

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Last modified: October 17, 2018

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