Nyctophilus geoffroyi facts for kids

Quick facts for kids Nyctophilus geoffroyi
Conservation status
Least Concern (IUCN 3.1)
Scientific classification

The Nyctophilus geoffroyi is a type of bat known as a vespertilionid bat. It's a flying mammal that is active at night. You can find this bat all over Australia, and it's quite common. People often call it the lesser long-eared bat because of its long ears.

What is a Lesser Long-eared Bat?

This bat is the main example for its group, called Nyctophilus. Scientists believe that the bat family it belongs to, Vespertilionidae, separated from another bat family, Molossidae (free-tailed bats), a very long time ago. This happened during the early Eocene period. It's thought that these bats first appeared somewhere in a supercontinent called Laurasia, possibly in North America.

Fossils of the Nyctophilus group are not very old. They only go back to the Pleistocene era. Scientists have found references to this specific bat species in these old fossil records.

A scientist named Oldfield Thomas studied this group of bats. He found that there were three different types, or subspecies, of the lesser long-eared bat:

• Nyctophilus geoffroyi: This is the original type described by Leach in 1821.

• Nyctophilus geoffroyi geoffroyi: This is the first type that was officially named.
• Nyctophilus geoffroyi pacificus: This type was first described by Gray.
• Nyctophilus geoffroyi pallescens: This type was found and described by Thomas. It is a paler bat that lives in dry areas.

How to Identify a Lesser Long-eared Bat

A drawing of a Lesser Long-eared Bat.

The lesser long-eared bat is a medium-sized bat. It usually weighs between 6 and 12 grams. Its forearm, which is part of its wing, is about 3 to 4 centimeters long. Its ears are quite long, measuring about 1.7 to 2.5 centimeters.

Its fur is light grey on its back. The fur on its belly is lighter, often white. Each hair is dark at the bottom and light at the tip. The color of their fur can change a lot. Bats living in dry, desert-like places are usually much paler.

A special feature of this bat is a small ridge on its nose. This ridge is about 1.5 millimeters high. It's split in the middle and connected by stretchy skin, making a Y-shape behind its nostrils.

Diet and Foraging Habits

When these bats fly, they point their long ears forward. They are listening for sounds that come from small openings on top of their snouts. These bats are known for flying very slowly when they are looking for food. They can slow down to just 4 kilometers per hour when flying through thick plants and trees.

Even though they fly slowly, they are very good at moving around. In forests, they fly 6 to 10 meters above the ground. They can suddenly change direction, even dropping straight down to catch insects near the ground. In open areas, they fly in circles around bushes. If they see prey on the ground, they can land, catch it, and then fly straight up again. They have even been seen hovering in the air and taking off from water! When they are just traveling, they fly faster, around 20 kilometers per hour.

Their favorite foods are grasshoppers, crickets, and moths. But they eat many other things too, like lacewings, beetles, flies, young crickets, cockroaches, and spiders. Scientists think they might be attracted to traps because of other insects already caught there.

These bats use different ways to hunt. They use echolocation, which is like sending out sound waves and listening for the echoes. This helps them find prey in the air, on leaves, and on the ground. They also use their eyesight for catching prey in the air. Sometimes, they use a method called "passive listening." This means they listen for sounds made by their prey without using echolocation or sight. This is how they catch crickets and other ground or air prey.

Some moths, like noctuid moths, have developed their own "ears" that can hear bat calls. However, they can't hear long-eared bats very well. This is because long-eared bats use a very quiet "whispering" technique instead of loud echolocation. This quiet sound bounces off the moths and is picked up by the bats' large ears.

Habitat and Distribution

The lesser long-eared bat can live in many different places. This makes it one of the most widespread bats that only live in Australia. You can find them in deserts, tropical forests, mountain woodlands, mangroves, farms, cities, and both wet and dry forests. They have been seen as high as 1600 meters above sea level, but they are more common at lower heights.

These bats are the most widely spread of their group, Nyctophilus. They live in both dry and wet areas. However, you won't find them in the tropical northeast coasts or the Cape York Peninsula.

They can live in Australia's dry regions if there is water available. They are often found near water sources like wells, pools, and dams used for farm animals. They are often seen with other bats like the inland free-tail bat (Mormopterus petersi) and the little and inland 'forest bats' (Vespadelus vulturnus and Vespadelus baverstocki).

They are very common in farming areas near the city of Canberra. Here, they live in buildings and tree hollows. They are one of several bat species that live in the city and hunt in nearby parks. They also live near the city of Perth in Kings Park, Western Australia. There, they share space with other small bats like the wattled bats (Chalinolobus morio and Chalinolobus gouldii) and the tiny free-tail bat (Mormopterus kitcheneri).

Behaviour

These bats are usually active at night. During the day, they live in dark places like caves, hollow trees, ceilings, and hollow walls. They are quite common across Australia, and their roosting (resting) habits vary a lot.

They prefer small, tight spaces. These can include peeling tree bark, tree hollows, caves, and buildings. They have even been found in nests of fairy martins (Petrochelidon ariel), rolled-up sleeping bags, under piles of bricks, hanging clothes, and once even inside a tractor's exhaust pipe!

Their social life varies too. Some bats live alone, while others live in small groups of two or three. Some groups, called maternity colonies, can have 10 to 15 bats with one adult male. Scientists found a group of 50 dead bats in the Nullarbor caves. A large living group of about 300 bats was found in an old warehouse in Western Australia.

Most bat groups often move to new roosting spots within a certain area. They might fly 6 to 12 kilometers from their roosts to their hunting grounds in nearby bushland.

When the temperature drops below a comfortable level, these bats' bodies work harder to stay warm. In Tasmania, when temperatures fall to 15 degrees Celsius or lower, they enter a state called torpor. Torpor is like a deep sleep where their body temperature and energy use drop a lot. A study found that Australian long-eared bats use torpor in a similar way to their relatives in other parts of the world. This helps them save a lot of energy and is very important for their survival.

Reproduction and Life Cycle

For male bats, the process of making sperm starts in November. It reaches its highest point in March and finishes in May. The sperm is stored in a part of their body called the epididymides.

Mating usually begins in April. The female bat then stores the sperm inside her body over the winter. In late August to September, the female releases an egg, and fertilization happens. The pregnancy, or gestation, lasts between 72 and 93 days.

Births happen from late October to November. In colder or higher places, births might happen a bit later. The mother often gives birth to two babies at a time. The young bats can fly by December, and the mother stops feeding them milk in early February. In Tasmania, scientists have seen shorter periods of mothers feeding their young. Older female bats might not give birth every year. This species has also shown "sperm competition," where sperm from different males compete to fertilize the egg.

See also

In Spanish: Nyctophilus geoffroyi para niños