BIOLOGY AND BEHAVIOR
The plain-nosed bats and the free-tailed bats are the two families of bats in Utah. The largest is the adult big free tailed bat with a wingspan of 17 inches and a weight of less than one ounce. The smallest, the adult western pipistrelle, is the size of a hummingbird and weighs 1/10 ounce. The fur color of these species is a mixture of tans, browns, rusts, and black, with some white accent.
Utah bats live in and use a variety of habitats as roost sites. These roosts may include caves and mines, tree foliage, hollow trees, cracks in rock cliffs, and buildings. Most Utah bat species are year round residents of the state that they hibernate during winter. Hibernation is a special adaptation bats use to survive cold periods when insects are not available. In late summer, bats prepare for hibernation by feeding heavily and accumulating extra body fat. Most bats are able to store enough fat to last through the hibernation period, which can last six months.
In the autumn, bats seek out cool environments, where they are able to lower their body temperature, breathing, metabolism, and blood circulation to begin hibernation. If repeatedly disturbed during hibernation, the bats may starve to death before spring. Because good hibernation sites are becoming scarce, thousands of bats of several species may gather in a single cave or abandoned mine. The average life span for a bat is 10 to 20 years. Natural enemies of bats include hawks, owls, cats, raccoons, snakes, bobcats, ringtails, and weasels.
DAMAGE AND DISEASES
The damage caused by bats is related to the animal's feces, called bat guano, and the danger of rabies transmission. Bat guano has potential to produce histoplasmosis, a fungus that forms on moist animal wastes. Histoplasmosis, when dry, forms a dust that if breathed into the lungs can cause flu-like symptoms in humans. Large concentrations of bat guano can irritate the eyes and produce a mess.
The danger of a bat can bite is not in the wound it inflicts but rather the potential to transfer a fatal disease. Pets should receive their rabies shots and these animals should not be handled because a bat will bite like other wild animals.
If a bat bites a person, the bat should be captured without damaging the head, and the local health department should be contacted to have the bat examined for rabies. If the bat is confirmed rabid, the person must undergo rabies treatments.