New Zealand lesser short-tailed bat, Mystacina tuberculata
The lesser short-tailed bat is only found in New Zealand and is the only living species of bat in the Mystacinidae Family. The short-tail is commonly located on the North Island of New Zealand using the forests as its habitat. Roosting is done primarily alone but there have been known colonies of over 100 bats. It prefers to use already hollowed trees or crevices but will chew out a burrow in the wood using its sharp incisor teeth. These roosting locations are only used for a few weeks but will also be reused at later times.
The lesser short-tailed bat is nocturnal, coming out of its roost for hunting 20 – 150 minutes after sunset. It usually hunts all night but spends 30 percent of that time hunting insects in the air, 40 percent feeding from plants, and the last 30 percent spent hunting the forest floor. While hunting in the air, the bat will fly no higher than 6 feet off the ground. In order to hunt the forest floor, the short-tail is able to fold its wings into a protective shield made up of membranes. It has strong hind limbs and sharp talons making it possible to move along the ground without flight. This ground feeding plays an important environmental role since this species helps pollinate the wood rose tree, which is an endangered plant that grows on the roots of other trees. The primary hunting is done by scent but this bat also uses hearing and echolocation. During the colder months it becomes sluggish and will remain in the roost for up to 10 days before emerging to hunt. If necessary, the short-tail will remain active instead of going into a state of hibernation.
In order to mate, the short-tailed bat uses a process called lek — this is where the males gather to put on a display for the females to determine which male they want. The male will occupy a roost alone and make repetitive ultrasonic calls that the females find attractive. The female will then go to the roosting spot that the male has marked with an oily, musky secretion.
The breeding seasons start in February and end in May. Once the male and female have mated the embryo is in a delayed implantation state during the winter so that the young is born during the warmer months. The newborn is hairless and weighs less than an ounce. The permanent teeth come in after three weeks and the body is completely covered with fur by four weeks. The young will leave the roosts at six weeks of age and are full grown within three months.
Image Caption: Mystacina tuberculata. Credit: GH Ford/Wikipedia (public domain)