Gray Sac-winged Bat - Reproduction

Reproduction

The female uses both ovaries and births one pup. It breeds once every year – the females are monoestrous and only produce one offspring. The females all give birth at about the same time every year. To mate, these bats swarm, flying around objects, and the males perform courting rituals in the air. It is thought that during flight, the sacs on the males release fragrances. The females reach sexual maturity after one year; the gestation period is four and one-half months and the pup is born weighing about 2 g. The young bat is then carried by the mother for one week. It can fly after two weeks, and is completely weaned at nine weeks. Females do not abort the fetus when there is a lack of food, and they also give birth when it is most convenient for the offspring, when weather and food are the best. The adult female survival rate data reflects the idea that the offspring take precedence over the adult, as the lowest percentage recorded was 54%. Depending on the place of residence, the timing of mating and birth is different. In Central America, the bats mate at the end of January to mid-February. Pregnant females of El Salvador can be found in May, while the pregnant females in Mexico can be found in May to July depending on where in Mexico it is. In Costa Rica, birth happens at the end of June, while in Mexico it can occur between the end of June to early July.