Bat Reproduction. Some Kinds of Bats

Reproduction. Among many species of bats, the males and females occupy different roosts. The males and females of some species even live in different regions of a continent except during the mating season. The mating season, which lasts for only a few weeks, may occur during the spring, fall, or winter, depending on the species. The female may carry the male's sperm within her body for several months before she becomes pregnant. In the spring, pregnant bats may leave their usual colony and join together in a nursery colony, where they give birth and rear their young.

The females of most species of bats have one baby a year. Some bats have a baby twice a year. A few species have up to four young at a time.

A newborn bat weighs about a fifth as much as an adult bat. Bats do not build nests, and so the infant must hold on to its mother or its home roost. Among some species, the infant clings to the mother for several weeks. The infants of other species stay in their roost, where they hang from a rock alone or with a group. Female bats nurse their young for six to eight weeks.

Some kinds of bats. Flying foxes and vampire bats are well known because of their unusual diet. Flying foxes eat mostly fruit, and vampire bats feed on the blood of other animals. Both live in tropical regions, where their feeding habits may damage the local economy. The most common bats in North America include brown bats, free-tailed bats, the hoary bat, the red bat, and the silver-haired bat.

Flying foxes and similar species known as fruit bats live in most tropical regions of Africa and Asia. These bats eat mostly fruit and occasionally damage orchards. Flying foxes also eat flower buds, nectar, and pollen. Flying foxes have large eyes and better vision than many other bats.

Vampire bats include a few kinds of bats that feed on the blood of other animals. The common vampire bat lives in Central and South America. It weighs about 1 ounce (28 grams) and has a wingspan of about 12 inches (30 centimeters). It preys mainly on cattle. It sometimes bites human beings, but such incidents are rare. Vampire bats approach their prey on foot. They scoop out a small piece of the victim's skin with their sharp teeth and then lick blood from the wound. Vampire bats consume about 1 tablespoon (15 milliliters) of blood a day. The wound they give their victims heals quickly, but these bats may carry rabies.

Brown bats include the big brown bat and the little brown bat, both of which live in the United States. Brown bats live in buildings or caves, and some migrate before they hibernate in winter. The big brown bat has dark brown fur and a wingspan of about 12 inches (30 centimeters). The little brown bat has dark brown fur and black forearms and ears. Its wingspan measures about 8 inches (20 centimeters).

Free-tailed bats are a group of dark brown bats that live throughout the world. Their tail extends beyond the tail membrane. A few kinds of free-tailed bats, especially the Mexican free-tailed bat, can be found in the southern United States. The Mexican free-tailed bat has large ears, sharp teeth, and a wingspan of up to 1 2 inches (30 centimeters). Mexican free-tailed bats live in colonies, mostly in caves.

The hoary bat, the largest bat of North America, has a wingspan of about 16 inches (41 centimeters). White hairs cover its reddish-brown underfur, giving the bat a spotted appearance. Hoary bats live alone in trees and migrate south for the winter.

The red bat has white-tipped red fur. The male is bright red, and the female is grayish-red. Red bats have short, rounded ears covered with fur. Their wingspan measures about 12 inches (30 centimeters). They live alone in trees and fly south every winter.

The silver-haired bat has dark underfur with white outer hair. Both males and females have brownish underfur, but the male has blacker coloring. The silver-haired bat has a wingspan of about 13 inches (33 centimeters). It lives in trees. In summer, the males live alone, and the females in groups. Some silver-haired bats hibernate in winter, but most migrate south.