The tent-making bat (Uroderma bilobatum) is an American leaf-nosed bat (Phyllostomidae) found in lowland forests of Central and South America. This medium-sized bat has a gray coat with a pale white stripe running down the middle of the back. Its face is characterized by a fleshy noseleaf and four white stripes. Primarily a frugivore, it may supplement its diet with insects, flower parts, pollen, and nectar. Its common name comes from its curious behavior of constructing tents out of large, fan-shaped leaves. These roosts provide excellent protection from the tropical rains, and a single tent roost may house several bats at once. This bat is quite common in its geographic range; hence, its conservation status is listed as Least Concern.
Taxonomy
The bat Uroderma bilobatum is a member of the family Phyllostomidae, which contains 49 genera and a greater variety in feeding habits than any other bat family. Carnivores, frugivores, and bats that specialize on blood or nectar and pollen are all represented in this family. Commonly known as the American leaf-nosed bats, phyllostomids are characterized by a special structure consisting of a leaf-shaped projection extending up from a “horseshoe-shaped” base attached to their upper lip. These bats send their echolocation calls out their nostrils, and so the noseleaf may help direct the sounds that they emit. Because they emit calls at such low frequencies, standard bat detectors have trouble picking up their calls. Thus they are sometimes called “whispering bats”.
Within Phyllostomidae is the subfamily Stenodermatinae, members of which are sometimes called tailless bats. These 17 genera from Central America have broad shoulders and faces and narrow tail membranes, with a tail that is either greatly reduced or absent. The upward projection of their noseleaf has two creases and the lower part is at least partly free. The shape of their faces has been correlated to their frugivorous diet. They are known to pick fruit with their mouths and carry it to a night roost to consume it. Thus, they are important seed dispersers for certain plants.
Bats in the genus Uroderma are characterized by a pale, white stripe that runs down the back and two pairs of white stripes on the face. Their tail membrane is curved into the shape of a U and lacks hair along its edge. This genus includes two species: Uroderma bilobatum Peters, 1866 and Uroderma magnirostrum Davis, 1968.
Uroderma bilobatum includes six subspecies: U.b. bilobatum Peters U.b. trinitatum Davis U.b. thomasi Andersen U.b. convexum Lyon U.b. molaris Davis U.b. davisi Baker and McDaniel
Etymology
The genus name Uroderma is said to be derived from the Greek words uro for “tail” and derma for “skin”, thus meaning “tail of skin”. This describes their tail membrane, which is made entirely of skin, lacking tail vertebrae. The proper word for “tail” in ancient Greek is however oura (οὐρά). The species name bilobatum is said to be derived from the Greek and Latin roots bi for “two” and lobat for “lobed” in reference to their first upper incisors, which have two lobes.
Description
Uroderma bilobatum is medium in size, weighing between 13–20 g with a body length of 59–69 mm. Typically, the females are slightly larger than the males. Their pelage ranges in color from dark gray to grayish brown, with their belly slightly lighter in color than their back. The individual hairs of their coat are bicolor, being lighter in color at the base than at the top. A thin, white stripe runs down the middle of the back from behind the head to the rump. The face has two striking symmetrical pairs of white stripes. One pair goes over the head, between and to the back of the ears. The other pair lies just below the eye. This facemask may serve a camouflage purpose by making their eyes less obvious to would-be predators. Their brown noseleaf and ears are rimmed with yellow or white. They have a U-shaped tail membrane that is practically hairless and measures 14–16 mm in length. A dorsal view of their skull reveals a depression between the frontal bone and their snout. Their dental formula is i 2/2, c 1/1, p 2/2, m 3/3, which gives them a total of 32 teeth. They also possess a calcar and a slightly pigmented, permanently open dactylopatagium minus.
Geographic distribution
These bats are found in Central America from Oaxaca and Veracruz, Mexico to Peru, Bolivia, and southeastern Brazil. They also live on the island of Trinidad. Most specimens have been collected at elevations below 600 m, but some have been found as high as 1500 m above sea level.