Lesser sheath-tailed bat  (Emballonura monticola)

The echolocation calls of this delicate bat are extremely distinctive, starting with a short sweep up the frequency range, followed by a steady constant frequency component between 48 and 51 kHz, and finishing with a final sweep down through the frequency range. Each call lasts just 6 – 8 milliseconds (6). The lesser sheath-tailed bat uses these calls to orientate itself in the forest, and to detect small insects to feed upon, by waiting for the returning echo of the call and building up a detailed picture of its environment.

It is thought that the lesser sheath-tailed bat has two breeding seasons each year; one in February and March, and the second in October and November. However, individuals have also been found to be pregnant at other times of year (2). Each female gives birth to a single pup, which she prevents from falling to the floor of the roost by scooping it to her body with her wing. At birth, the pup weighs a quarter of its mother's weight (this is normal in bats, but extraordinary in much of the rest of the mammalian class). The mother will forage with her pup clinging to her belly until it becomes too heavy to carry. Soon afterwards the pup is weaned, and within a year it will become a mature adult (7).