Bats are mammals. They account for more than 25 percent of all the mammals on the earth! Bats are the only mammals that can fly. Many Alaskans are unaware that bats live in their state. Alaska is home to five species of bat, with the Little Brown Bat (Myotis lucifugus) being the most common by far. This species is found throughout Southeast, Southcentral
and Interior Alaska. All other bat species are almost
exclusively found in Southeast Alaska. The Big Brown
Bat has only been recorded once in Alaska in 1955, so is
not counted among the five species.
Bats are only found in forested areas; no bats have been found in the treeless regions of the western and Arctic tundra or Aleutian Islands. Being nocturnal animals, bats sleep during the day and hunt and feed during the night. Alaska bats feed on insects such as moths, mosquitoes, beetles, mayflies, caddis flies and midges. The decreasing length of summer nights at high latitudes reduces foraging opportunities and thereby caloric intake, which potentially limits the distribution of these mammals. Bats are not blind. They can see better than humans at night, however echolocation is their most important sense when hunting.
Bats may roost in multiple areas depending on the time of day, their pregnancy status, prey availability, etc. Because many bats choose to roost or nest in hidden areas such as closets, attics or the eaves of buildings, occasionally humans come into contact with bats.
The little brown bat is a small mammal with a body length of 3 - 31/2 inches and weighing approximately 1/8 to 1/2 an ounce. The wingspan of little brown bats range from 6 - 8 inches. As their name suggests little brown bats are glossy brown above with a light buff color below. These bats can live 20 to 30 years. In summer the little brown bat inhabits trees, bat houses, and buildings, usually choosing a hot attic, where nursery colonies of hundreds and even thousands form. Less frequently colonies form beneath tar paper, siding, shingles, or other similar sheltered spots,. In the west colonies have been found beneath bridges and in caves. Single males have been found in attics, behind shutters under bark, in rock crevices, behind siding and under shingles. Groups of males occasionally occur in caves.
The silvered-haired bat is a medium-size bat. It's dark brown-black hairs are tipped with silver giving it an icy appearance. The silver-tipped hairs do not extend to the face or neck. Their ears are short, rounded and without fur. The silver-haired bats are migratory, and sometimes migrate in groups. There are several records of groups of weary bats descending upon ships at sea. Some bats netted during summer months and banded were recaptured over 100 miles away! A typical day roost for the silver-haired bat is the space behind a piece of loose bark on a tree. Individuals have also been found in woodpecker holes and on bird's nests. During migration they may be encountered in a wide variety of other shelters. Although they may appear in any kind of building, they favor open sheds, garages, and outbuildings rather than enclosed attics. They frequently rest in a pile of slabs, lumber, railroad ties, or fence posts, especially when migrating through the prairies where shelters are scarce.
Keen's myotis is a medium-sized, long-tailed bat, found near coastal forests in the US in Washington state and Alaska. It roosts in caves, rock crevices, tree cavities, and under tree bark in the summer, sometimes in small colonies. Larger groups of Keen’s myotis form colonies to hibernate together in the winter, sometimes alongside other species of bats. Unfortunately for the homeowner, they will roost in buildings and attics as well. Like many bats, Keen’s myotis hunt insects at night and are most active shortly after sunset and shortly before dawn.
he long-legged bat primarily inhabits forested mountain regions, where it roosts in trees, rock crevices, cracks and crevices in stream banks, and in buildings. It also may be found in streamside and desert habitats in some areas. This bat emerges early in the evening when it is still twilight, and it is a rapid, direct flier that pursues prey over relatively long distances through, around, and over the forest canopy. This species is active throughout most of the night, although there is a peak of activity in the first 3-4 hours after sunset. It is moderately gregarious in maternity colonies and during swarming in late summer and hibernation. Hibernation sites include caves and mine tunnels. There usually are more males than females at hibernation sites. The ability to fly at cool temperatures may enable this species to extend the prehibernation period of activity. The long-legged bat feeds primarily on moths, although it also consumes other, primarily soft-bodied invertebrates, including flies, termites, lacewings, wasps, true bugs, leafhoppers, and small beetles.
The California bat feeds on small flying insects, primarily flies, moths, and beetles. Its foraging strategy consists of locating and feeding in concentrations of insects where its slow maneuverable flight allows it to capture several insects in quick succession over a short distance.