During birthing, the mothers firmly anchor themselves in horizontal positions, hanging by their thumbs and feet and curling their tail membranes over the vaginal opening. They resume normal hanging postures soon after giving birth and cradle the babies beneath their wings. Within minutes, mothers begin grooming their young and continue until the pups are clean and dry about eight to ten minutes later. The placenta remains attached for up to 90 minutes, protecting babies from potential falls. One researcher observed a baby that fell but was saved by its umbilical cord, which it used to climb back to its mother.
Babies are hairless at birth except for a few patches of fine, silvery-gray fur.
They begin to make high-pitched chirps on the second day, and on the third day their eyes and ears open. Mothers easily carry their young in flight for the first week but do so only to change roosts. Within 22 days the young resemble adults, and they can fly nearly as well as adults in 44 days. Mothers often travel up to 12 miles to feed and, upon return, must find their well-concealed young in the foliage. They recognize their babies' calls and communicate with them when reuniting.