VESPERTILIONIDAE

large family of bats, suborder Microchiroptera, including almost 300 species known collectively as common bats. Vespertilionids are found worldwide in tropical and temperate regions. Their habitats are as varied as jungles and deserts. The vespertilionids are nocturnal bats with small eyes and well-developed tails. Most species have long wings, and some have very large ears. The fur is generally gray, brown, or blackish; but it may be red, as in red bats (Lasiurus), grizzled, as in frosted bats (Vespertilio), or marked with white, as in spotted bats (Euderma). The Philippine bamboo bat, possibly the smallest of bats, is a vespertilionid about 4 centimetres (1 1/2 inches) in head and body length; it weighs about 1.5 grams (1/20 ounce) and has a wingspan of 15 cm. Other vespertilionids range up to 10 cm in head and body length and 50 g in weight. Most vespertilionid bats feed on insects, often catching their prey in the membrane between their hindlegs before seizing the insect with their teeth. The fish-eating bat (Pizonyx) and a few species of brown, or mouse-eared, bats (Myotis) prey on fish. In general, the vespertilionids live in colonies and roost in caves, hollow trees, and similar shelters. Some have been found in the twigs of birds' nests and in roof thatching; others habitually roost in branches, on tree trunks, or in the hollow core of bamboo stalks. Many vespertilionids inhabiting temperate regions hibernate or migrate in winter. For more information about vespertilionid groups and species, see brown bat; pipistrelle; noctule; red bat; hoary bat; barbastelle; long-eared bat.