There are two species of true tent making bat (Uroderma sp.) in the Amazon rainforest. The
tent-making bat is so-called because it makes a place ("tent") to roost when it sleeps during the
day. However, a number of different bats make their own roosts. The reason for this behavior is not clear.
It may be to shelter more effectively from rainfall. Most bats live in caves or in natural cavities such as
holes in trees. But sometimes a good place can be hard to come by. Also, if the bat has to return to the
same place every night, it cannot fly too far from home which could be a problem if food is scarce. The
tent-making bat has solved this problem. It makes its own home! It does this by chewing the center rib of a
large leaf that looks like a banana tree leaf. Often it is a heliconia plant (see photo). When the bat chews the rib of the leaf, the
leaf folds over like an upside-down V, making a roof like a tent. That's where it rests for the night.
However, a bat might not always find a good leaf, whereupon it will find any suitable place to rest. (See photo)
APPEARANCE
The commonest tent-making bat in the Amazon, U. bilobatum, is a medium-sized bat covered with dark
gray-brown fur. Its diagnostic feature is the presence of two white stripes along the top of the head (and
two on the face) and a single white stripe along the back. It has a "noseleaf" typical of many bats,
an adaptation to use of sonar—emitting and detecting sound for navigation and prey detection. This
character assigns it to the Leaf-nosed bats, Phyllostomidae family.
HABITAT AND DISTRIBUTION
Several kinds of bats make their own roosts, although this is rare among bats, which mostly use existing
cavities such as caves or tree-holes. The tent-making bat makes its tent by cutting down the side of a
leaf's main rib, causing the sides to droop down. The bats roost hanging from the rib, clustered in
small groups of up to 50. It can make different styles of tents, depending on the type and size of leaf. The
species is common and widespread, found throughout tropical America west of the Andes from southeast Brazil
and Bolivia to southern Mexico It is adaptable to disturbed as well as mature rainforest and cultivated
areas such as plantations and gardens, although limited to elevations below 3,000 feet.
FEEDING AND DIET
Tent-making bats feed on insects, as do most bats and, like many tropical bats, on fruit and nectar. Insects
are usually caught on the wing, while the bat will hover or crawl to access fruit and flowers.
BREEDING
The breeding biology of tent-making bats is not well-known. Thomas Kunz in his article The World of
Tent-making Bats (1994, BATS 12(1): 6-12) suggests that their group roosting behavior implies a polygynous mating system. One male bat lives with
several females, from five to 15 bats, in a harem. The male protects his harem living in his tent to prevent
rival males from taking over. The harem may stay intact for the life of the female whereas the males can
rule only so long as they are able to fend of challengers, perhaps up to three years. The male retains his
group for as long as three years, while the females may stay together much longer, perhaps even for life.
During mating season, females and the male cohabit in the tent, while unattached males without a harem roost
alone. Between mating seasons the females and young roost without the male.
CONSERVATION
Tent-making bats are common and not presently at risk. However, they rely on vegetation to make roosts and
could be vulnerable if urban development is not controlled.
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