Lesser Long-eared Bat

The lesser long-eared bat is a medium-sized species, weighing 6 to 12 grams, with a forearm length ranging from 30.6 to 41.7 mm; it also has long ears which can vary between 17.6 and 25.3 mm in length. Light grey coloured fur is located on the back of the bat contrasted by the lighter to white fur on its underbelly. The hair is bi-colored, dark at the base to light at the ends. The colour of the fur is highly variable, and those in arid regions are notably paler. The distinguishing feature of this species is a nose ridge around 1.5 mm high, split and connected by an elastic membrane of skin, creating a Y-shaped groove behind the nostrils.

The species is highly adaptable to a variety of habitats, and as a result is one of the most widespread endemic bats of Australia. It lives in deserts, tropical to alpine woodlands, mangroves, agricultural land, urban areas, wet to dry sclerophyll forests and rain forests. They are recorded at areas around 1600 metres asl, but more common at lower altitudes. The most widely distributed of the genus Nyctophilus, ranging arid to wet regions, they are nevertheless absent from the northeast tropical coasts and Cape York Peninsula. Nyctophilus geoffroyi is able to inhabit the arid regions of the country when water is available. It is commonly recorded at bore wells, pools, and dams for livestock, in association with the inland free-tail Mormopterus petersi, and the little and inland 'forest bats' (Vespadelus), V. vulturnus and V. baverstocki. They are especially common in agricultural areas near the city of Canberra, where they occupy buildings as well as tree hollows, and one of several bats to have taken residence within the city and forage in nearby parks and reserves. They occur near the city of Perth at Kings Park, Western Australia with other microbat species, the wattled Chalinolobus, C. morio and C. gouldii, and tiny endemic freetail Mormopterus kitcheneri.

When flying this species will point the tips of its ears forward listening for sound emitted from small openings located at the top of their snouts. The species is known to have one of the lowest flight speeds when foraging, slowing to 4 km/h when flying into the understory and through vegetation. Despite this it has high manoeuvrability and while in forests 6–10 m above the ground, it can switch suddenly in direction, sometimes dropping vertically to just above the ground to catch insects. In open areas they will spiral around bushes and shrubs, if they spot prey on the ground they can land capture their victim and then relaunch almost vertically. There have been observations of the species hovering as well as the ability to take flight from water. Records show that they commute around 20 km/h. Grasshoppers, crickets and moths are their most common food but have a large variety of foods including: lacewings, beetles, flies, cricket nymphs, cockroaches and spiders. It is believed that their capture in pit-traps is due to them, being attracted to previously captured insects. Their hunting techniques have notable diversity in that they use echolocation (peak power frequency 47.7 kHz; range 47–48 kHz) for capturing aerial, foliage and ground inhabiting prey. …