Bats are mammals of the order Chiroptera whose forelimbs form webbed wings, making them the only mammals naturally capable of true and sustained flight. They are reclusive creatures of the night and suffer their own plagues. Native species of bats have now returned to Boulder Colorado for the summer. Unfortunately, these bats have a high rate of infection with the rabies virus, which is 100 percent fatal to humans. However, an extremely effective rabies vaccine can provide immunity to rabies when administered after an exposure (post exposure prophylaxis) or for protection before an exposure occurs (preexposure prophylaxis).
Flight has enabled bats to become one of the most widely distributed groups of mammals. Apart from the Arctic, the Antarctic and a few isolated oceanic islands, bats exist all over the world. Bats are found in almost every habitat available on Earth. Bat habitats have two basic requirements: roosts, where they spend the day or hibernate, and places for foraging. Bat roosts can be found in hollows, crevices, foliage, and even human-made structures, and include tents the bats construct by biting leaves.
The United States is home to an estimated 45 to 48 species of bats. The three most common species are Myotis lucifugus (little brown bat), Eptesicus fuscus (big brown bat), and Tadarida brasiliensis (Mexican free-tailed bat). The little and the big brown bats are common throughout the northern two-thirds of the country, while the Mexican free-tailed bat is the most common species in the southwest.
Bats are natural reservoirs for a large number of zoonotic pathogens, such as rabies, and severe acute respiratory syndrome (SARS). Their high mobility, broad distribution, and social behavior (communal roosting and fission-fusion social structure) make bats favorable hosts and vectors of disease. Many species also appear to have a high tolerance for harboring pathogens and often do not develop disease while infected.
In regions where rabies is endemic, only 0.5% of bats carry the disease. In the United States, bats typically constitute around a quarter of reported cases of rabies in wild animals. However, their bites account for the vast majority of cases of rabies in humans. Of the 36 cases of domestically-acquired rabies recorded in the country in 1995—2010, two were caused by dog bites and four patients were infected by receiving transplants from an organ donor who had previously died of rabies. All other cases were caused by bat bites.
Rabid bats may be clumsy, disoriented, and unable to fly, which makes it more likely they will come into contact with humans. One should avoid handling them or having them in one's living space, as with any wild animal. If a bat is found in living quarters near a child, mentally handicapped person, intoxicated person, sleeping person, or pet, living in an area where rabies is known to occur, the person or pet should receive immediate medical attention for rabies. Bats have very small teeth and can bite a sleeping person without being felt.
If you discover a bat in your apartment or home, immediately cover the bat with a box; close the door to the room and keep friends, family members and animals away. Immediately contact your local animal control agency for further instructions.
For further information see Rabid Bats.
Bat image via Wikipedia.