Keen's Long-eared Bat belongs to the mammal Order Chiroptera to which all bats belong (chiro means hand, ptera means wing) and to the Family Vespertilionidae.
German's refer to them as "fleuder-mouse" or flying mouse. In fact, some scientists believe they are more closely related to primates because of the structure of their hands (wing).
Like all bats, they hunt using echolocation. A sound of 20 khz or higher is sent out from the vocal chords and large ears help the bat to detect and determine the size and direction of the object the sound bounces off.
All of the bats in the Pacific Northwest are insectivores, eating as many as 600 mosquitoes per hour, or 3000 per night.
Keen's Long-eared Bats are found only in the coastal forest regions of south-eastern Alaska to Northwest Washington, including Queen Charlotte Islands and the BC Coast. They have been noted inland on the northeast shores of Cultus Lake in BC.
A small bat with a wingspan of less than 26cm, and weighing about the same as two nickels and a dime, Keen's Bats are covered with a dense layer of short darker brown hair which is darker above than below. They also have darker shoulder patches. Their wing leather is a dark brown but not black. Long ears extend beyond the nose when pressed forward and the outside of their tail is fringed with small hairs that can be seen with a hand lens. They are difficult to tell apart from the similar looking Western Long-eared bat, Myotis evotis who is much more common and has a wider range.
Baby bats are caught in the female's wing skin when they are born and weigh as much as 1/4 of the mother's weight. At first, babies are carried while hunting for insects, then as they grow, they are left behind with other babaies. Mothers recognize their young by their voice. Only one pup is born per year. They start to learn to fly by about 6 weeks of age. They will not mate until the next autumn.
Not much is known about the Keen's bat, except from the few dead specimens that are found in BC natural history museums and one small colony found in a cave in a BC hotspring. Most of the population is thought to be within BC coastal rainforests.
From studies of the BC bats, scientists believe they may be solitary bats who roost in tree cavities, rock crevices and small caves. They are believed to hunt along forest edges and in openings and over ponds as many other bat species do, flying slowly as it hunts. Like other bats, it eats moths and other insects by catching them in the mouth, wing skin or tail skin. Most bats mate in the fall, store the sperm until spring and the young, are born in June.
The Keen's Long-eared bat is on B.C.'s red list (considered endangered) because the overall population is not known.
Much research still needs to be done on this rare bat.
by Donna Hill B.Sc. B.Ed. 1998
Good Book on Bats:
Bats of British Columbia Royal British Columbia Museum Handbook by David Nagorsen & R. Mark Brigham