Go Batty For Bats!

Nineteen species of bats have been recorded in Canada, and 17 of them are regular residents. In many ways, bats are typical mammals - they are warm-blooded and they give birth to live young and suckle them. They differ from all other mammals, however, in their ability to fly. Their wings are folds of skin stretched between elongated finger bones, the sides of the body, the hind limbs, and, in Canadian species, the tail. A resting bat usually hangs head downward and takes flight by releasing its toehold.

Flying bats appear larger than resting bats because of their large wing area. For example, the Little Brown Bat, which is the most common Canadian bat, weighs only about 8 grams (this is equal to the weight of two nickels and a dime) but has a wingspan of about 22 centimetres. The Hoary Bat is the largest Canadian species. It weighs 30 grams and has a wingspan of 40 centimetres. The smallest Canadian species, the Small-footed Bat weighs 5 grams.

Bats are primarily nocturnal creatures, sleeping during the day and hunting and feeding at night. Although some bats in the Tropics feed on fish, fruit, nectar, or even blood, the bats of Canada feed on insects, usually caught in flight. Bats will take moths, mosquitoes, beetles, mayflies, caddis flies, and midges. Insectivorous species of bats typically consume 30 - 50% of their body weight in insects each night. This is equivalent to a 60 kg person eating 20 - 30 kg of food in one day!

Bats are not blind. Although the eyes of many insectivorous bats are difficult to see, bats can see very well and rely on vision for many aspects of their behaviour. However, as far as we know, Canadian species use echolocation rather than vision to locate their prey. Echolocation is an active mode of orientation in which the bat emits pulses of sound and listens for the returning echos using its large ears. The difference between the original sound and its echo contains the information used by the bat to locate and identify objects in its path. Echolocation is also used by marine mammals, such as dolphins and other toothed whales, some cave-dwelling birds, and mammals such as shrews.

In the summer, some bat species live in colonies, while others live alone. Some roost in buildings while some are tree-roosting. Others roost in cracks and crevices in cliffs. In the fall, when the weather gets cooler and the insects start to disappear, Canadian bats hibernate. In Canada, bats are divided into two groups based on their seasonal movements. Some travel up to several hundred kilometres in order to hibernate. They often hibernate in caves. Other species, such as the tree-roosting bats, migrate to more southern locations where they may hibernate in hollow trees or remain active.

Although bats are gentle and intelligent creatures, they are wild animals and should never be picked up.

<< Back to Wildlife Articles