years ago. Twenty million years ago, two genera emerged from the family; Mystacina and Icarops. Fossils of Icarops have been found throughout Australia, indicating the now-extinct species was once well dispersed there. It is unknown when the species within this genera (I. aenae, I. breviceps, and I. paradox) became extinct. Mystacina migrated from Australia to New Zealand, settling as the first mammals on these islands. Based on fossil evidence, this genus was definitely in New Zealand during the Miocene. Therefore we know that Mystacina became a distinct genus around 20 million years ago and travelled from Australia to New Zealand anywhere from approximately 5.3 - 20 million years ago. This assumes that Icarops did not migrate to New Zealand, and that the colonisation event occurred after the genera became distinct. It is unclear when M. tuberculata and M. robusta became distinct species. Distribution and range Lesser short-tailed bats have been found in a few populations dispersed around the country. There are populations on both of the main islands, as well as various surrounding islands. There are a few key populations currently known. There is one on Little Barrier Island (Hauturu), one near the top of the North Island, seven in the central area of the North Island, and one on the south-eastern side of the North Island. There are at least two on the mainland of the South Island; and one on Codfish island further south. The bats can live at a wide range of altitudes, from sea level to high up among the forest-covered mountains. M. tuberculata prefer to live in untouched forest settings. However, they have been reported in various habitats, such as farmland and shrubland. Anatomy and physiology The lesser short-tailed bats appear similar to their microbat relatives. They are small in size, and typically weigh between once fully grown. They have relatively large ears compared to their head and body sizes, which face forward to assist with echolocation. Lesser short-tailed bats also have relatively large nostrils that face outwards, allowing these animals to use olfaction to guide their movements. Their eyes are small and their vision is relatively weak, justifying their reliance on sound and olfactory senses. These features are common throughout Chiroptera. Their wings are relatively smaller than those of other bat species. Because of this, they have reduced agility, and cannot fly as fast. Despite this, they are still very capable of flight; just