Bats are the only mammals capable of sustained flight, making their life cycle unique. With over 1,400 species globally, they vary significantly in size and diet, but all give birth to live young. They dedicate considerable energy and time to raising their offspring, ensuring the next generation can eventually fly.
The Specific Name for a Baby Bat
The young of a bat is officially known as a “pup,” a term shared with the offspring of dogs and seals. A newborn pup is remarkably small, often measuring only one to two inches and weighing less than an ounce. In some species, a pup can weigh up to one-third of the mother’s weight at birth.
Pups are born highly dependent, typically blind with closed eyes and mostly naked, possessing fine, pinkish skin. They are born with specialized, hooked milk teeth that allow them to firmly latch onto their mother for nursing and transport.
Early Care and Dependence on the Mother
Female bats gather in specific, warm, protected environments called maternity roosts or colonies to give birth and raise their young. Most bat species only give birth to a single pup per year.
The mother provides constant care, keeping the pup warm and nursing it with nutrient-rich milk. Bat pups are altricial, meaning they are born underdeveloped and completely reliant on their mother for nutrition and warmth for the first few weeks.
While some species carry their young when foraging, most mothers leave their pups hanging safely in the roost while they hunt at night. The mother-pup bond is maintained through highly developed senses; a mother bat locates and identifies her own pup among thousands in a dense colony using unique vocalizations and scent recognition.
Development and Independence
The developmental phase for a bat pup is marked by rapid physical change, preparing them for flight. Pups generally open their eyes within a few days to two weeks after birth. Their fur develops shortly after, transitioning to a full coat within a couple of weeks.
As they grow, their temporary milk teeth are replaced by a permanent set, signaling the beginning of weaning. Weaning involves a gradual transition from the mother’s milk to the adult diet of insects, fruit, or nectar, depending on the species. This coincides with developing the physical and behavioral skills needed for flight.
Pups start stretching and flapping their wings in practice. Within three to six weeks, they begin short, controlled flights, a stage called fledging. The juvenile bat achieves full independence and leaves the maternity colony to forage on its own, often just a few weeks to a couple of months after birth.