Disk-Winged Bats: Thyropteridae

Physical characteristics: Fur color of Spix's disk-winged bats ranges from dark brown to reddish brown. Their undersides are a cream or yellow, and their ears are blackish. The sides of their bodies are an intermediate color, which is why they were given the name tricolor, which means to have three colors. These bats weight about 0.14 ounces (4 grams). They have a head and body length combined of 1 to 1.5 inches (2.7 to 3.8 centimeters). Females are slightly larger than males.

Geographic range: Spix's disk-winged bats are found in tropical forests from Veracruz, Mexico to southeast Brazil.

Spix's disk-winged bat roosts with its head upright. Most other bats, besides disk-winged bats, hang upside down. (Brock Fenton. Reproduced by permission.)

Habitat: Spix's disk-winged bats have been found in rainforests, swamps, and clearings. They have generally been found living below 2,625 feet (800 meters) and have not been recorded living above 4,265 feet (1,300 meters).

Diet: Spix's disk-winged bats feed on insects, such as small beetles and flies. Spix's bats eat about 20 percent of its weight each night.

Behavior and reproduction: This species roosts in young, partly uncurled leaves. They are found roosting in leaves of heliconia plants, recognizable by their large leaves. Roosts contain about six individual bats, composed of one or more adult males, several females and several juveniles of both sexes. Female Spix's bats have been observed taking their offspring for the evening flight in search of food.

These bats are polygynous, meaning that the bats mate with more than one female at a time. These bats breed twice annually. Gestation (pregnancy) lasts about two months. For the first month of life offspring either remain in the roosts or cling to their mothers when they go out to feed, even though young can weigh up to 46 percent of the mother's weight. Offspring can generally fly after one month.

Spix's disk-winged bats and people: Aside from eating insects some people consider pests, these bats have no known significant relationship with people.

Conservation status: These bats are not considered threatened. ∎