Four bat species in Ontario are susceptible to White Nose Syndrome (WNS). WNS is caused by a fungus accidentally introduced to North America in 2006. The fungus grows in caves such as those used by hibernating bats. The fungus infects hibernating bats, growing on their bodies and around their faces. Because of this infection, affected bats wake up repeatedly through the winter, depleting their energy stores. As there is no food available in the winter to replenish their energy stores, many bats do not survive.

Like all of our wildlife, bats require places to live and to find food. Species in Ontario must also be able to travel to overwintering sites where they can survive the cold winter. Losing these resources can make life difficult for our bats. Further, bats are slow breeders and it takes a long time to replace any individuals lost from the population.

Bats that fly too close to turbines are killed by hitting the blades, or by the low air pressure surrounding them. Turbines appear to have the greatest impact on long-distance migratory species, including eastern red, hoary and silver-haired bats in Ontario. We have a poor understanding of the size and health of populations of these species, making it hard to gauge the impact and risk of turbines. With careful planning, it may be possible to manage wind farms to minimize their impact on bats.

Although not a threat in itself, bats’ slow reproduction exacerbates the other threats they face and complicates recovery. Most bats only have one offspring a year. Some have twins, while triplets or larger litters are rare. Females have long lives, and in difficult years they may not reproduce at all. Females have such small litters because, as mammals, they carry their young internally, but must still be light enough to fly!