New Zealand Short-Tailed Bats: Mystacinidae

New Zealand short-tailed bats are active on the ground more than any other species of bat. Like all other bats, they are nocturnal, meaning they are active at night. Several hours after dusk, they begin foraging for food by running along the ground, up trees, and along tree branches.

These bats typically roost in the hollow trees of forests. They have also been found roosting in caves, houses, and in burrows, holes that they dig in the ground. Observations have shown that these bats roost in large groups of 100 to 500 individuals during the day. They also may roost in far smaller groups, and sometimes singly. When the weather becomes cooler, the bats go into a state of inactivity called torpor, but they will come out of their roosts on warmer winter nights to forage, or search, for food.

To find food, New Zealand short-tailed bats use echolocation (eck-oh-loh-KAY-shun), a technique in which the bats detect objects by sending out high-pitched calls and then listening to the reflected sound. They also find prey, animals hunted for food, by listening for movements and using their sense of smell. They commonly hunt prey on the forest floor, often forming burrows or holes under leaf litter in the ground to forage for food. When they tuck their wings away, these bats use the front arms like front legs, which helps them move along the ground.

Female New Zealand short-tailed bats give birth to one offspring once a year. The timing of mating and births appears to vary according to their location. Limited observations of the greater New Zealand short-tailed bat suggest that a single young may be born from spring to autumn.