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| Silver-haired Bat - Lasionycteris noctivagans |  Wingspread: 10.6-12.2 inches. Weight:0.21-0.52 oz.
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Named for their "frosted" appearance, these bats are blackish in color with white hairs intermingled. In Utah the silver-haired bat occurs commonly in the summertime in the higher elevation mountains. It commonly feeds early in the evening above mountain meadows and forest openings. It is a slow flying bat, preying on insects, and is often seen foraging near the ground.This bat is widespread, occurring throughout Alaska, Canada and all of the contiguous United States except Florida. It is, however, primarily a northern species.
These are solitary bats, roosting on the outside of trees during the day. They have long, thick black fur with silver tips. They appear to be neotropical migratory bats, traveling south into Mexico and possibly farther during the winter months. Come spring they migrate north and appear to segregate themselves by sex with the males going to the western states and the females going to the eastern states within the US.
Silver-haired bats are among the most common bats in forested areas of America, most closely associated with coniferous or mixed coniferous and deciduous forest types, especially in areas of Old Growth. They form maternity colonies almost exclusively in tree cavities or small hollows. And like many forest-roosting bats, silver-haired bats will switch roosts throughout the maternity season. Because silver-haired bats are dependent upon roosts in Old Growth areas, managing forests for diverse age structure and maintaining forested corridors are important to these bats. It is estimated that these bats require snag densities of at least 21 per hectare and often forest management practices have fallen far short of this figure. Unlike many bat species, silver-haired bats also appear to hibernate mainly in forested areas, though they may be making long migrations from their summer forest to a winter forest site. Typical hibernation roosts for this species include small tree hollows, beneath exfoliating bark, in wood piles, and in cliff faces. Occasionally silver-haired bats will hibernate in cave entrances, especially in northern regions of their range. Like big brown bats, the silver-haired bats have been documented to feed on many insects perceived as pest species to humans and/or agriculture and forestry. Even though they are highly dependent upon Old Growth forest areas for roosts, silver-haired bats feed predominantly in disturbed areas, sometimes at tree-top level, but often in small clearings and along roadways or water courses. Though their diets vary widely, these bats feed chiefly on small, soft-bodied insects. Silver-haired bats have been known to take flies, midges, leafhoppers, moths, mosquitoes, beetles, crane flies, lacewings, caddisflies, ants, crickets, and occasional spiders. |
| | Western Red Bat - Lasiurus blossevillii | Wingspread:11.4-13.1 inches. Weight: 0.4-0.52 oz.
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As its name suggests, this is a colorful bat varying from bright reddish (males) to yellowish(females) in color with pointed wings.Its distribution is western Canada, western United States, western Mexico, and Central America.In Utah, a few records from Washington and Carbon Counties account for this species' occurrence in the state.
This bat is poorly known in Utah and is currently listed as a Species of Special Concern by the Utah Division of Wildlife Resources.It is association with riparian habitats. Red bats are known to commonly have more than one young.
Several in the genus Lasiurus are commonly referred to as 'tree bats' because they roost only in tree foliage. The desert red bat is a typical tree bat, which is closely associated with cottonwoods in riparian areas at elevations below 6,500 feet. Especially favored roosts are found where leaves form a dense canopy above and branches do not obstruct the bats' flyway below. Desert red bats are also known to roost in orchards, especially in the Sacramento Valley of California. Despite their bright amber color, these bats are actually rather cryptic, resembling dead leaves when they curl up in their furry tail membranes to sleep. Like all tree bats, this species is solitary, coming together only to mate and to migrate. Tree bats often give birth to twins, and desert red bats can have litters of up to four pups, though three is the average. These bats typically feed along forest edges, in small clearings, or around street-lights where they prefer moths. It is not known exactly where desert red bats hibernate, though they may burrow into leaf litter or dense grass like their eastern counterparts, and they do move to milder coastal areas in the Pacific Northwest. Although largely undocumented, desert red bats appear to have declined markedly in the West due to the loss of lowland riparian forests. |
| | Hoary bat - Lasiurus cinereus |
 
Wingspread: 14.9-16.2 inches. Weight:0.70-1.22 oz.
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This is the most widespread of all of our North American bats, occurring in all states except Alaska. The hoary bat, named for its beautiful frosted or 'hoary' coat, is a relatively large bat with long pointed wings. It is closely associated with trees and can be found in wooded areas in the summertime. At lower elevations, it appears to be restricted to riparian areas. Hoary bats are migratory.
A solitary bat, the hoary bat may be found roosting singly in the foliage of trees during the day. Hoary bats are open air predators with a swift and direct flight pattern. They emerge late in the evening to feed on moths which they prefer, but also beetles, wasps, grasshoppers, and even other small bats.
They are very similar to, but larger than the Silver-haired bats. These are also solitary bats, roosting on the outside of trees during the day. They have long, thick brown fur with a cinnamon to blond mane around their head. They appear to be neotropical migratory bats, traveling south into Mexico and possibly farther during the winter months. Come spring they migrate north and appear to segregate themselves by sex with the males going to the western states and the females going to the eastern states within the US. Primarily males are found in Utah.
Hoary bats are one of America's largest and most handsome bats. With their long, dense, white-tipped fur, they have a frosted, or hoary, appearance. Humans rarely get the chance to see these magnificent bats; they are not attracted to houses or other human structures, and they stay well-hidden in foliage throughout the day. They typically roost 10-15 feet up in trees along forest borders. In the summer, hoary bats don't emerge to feed until after dark, but during migration, they may be seen soon after sundown. They sometimes make round trips of up to 24 miles on the first foraging flight of the night, then make several shorter trips, returning to the day roost about an hour before sunrise. Between late summer and early fall, they start their long journey south, migrating to subtropical and possibly even tropical areas to spend the winter. Traveling in waves, they are often found in the company of birds, who also migrate in groups. For the rest of the year, however, hoary bats remain solitary. They are among the most widespread of all bats, found throughout most of Canada and the United States and south into Central and South America. The hoary bat is Hawaii's only native land mammal. Stray individuals have been found from Iceland to Orkney Island as well as in Bermuda and the Dominican Republic. |
| | All Photos by M.Siders |
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