Tube-nosed bats are some of the strangest looking bats you might find, but in a weird way they are also some of the most endearing!
The Queensland or Eastern tube-nosed bat, Nyctimene robinsoni, is a megabat in the familyPteropodidae that lives in northeastern Australia. As its name suggests, these bats have long tubular nostrils. Scientists are not really sure why these tubes evolved but they have several theories as to what purpose they serve.
Eastern tube-nosed bats eat mainly fruit and nectar from the rainforest canopy. Some scientists believe that their tube-like nostrils to help the bats breath, like a snorkel, when they are eating a juicy fruit! Other theories include roles in olfaction, acting like stereo nostrils, allowing the bat to home in on a piece fruit in the rainforest understory.
Tube-nosed bats that live in rainforest habitat often have a green tinge to their wings or fur, which helps keep them hidden in foliage during the day. Eastern tube-nosed bats are a rich brown colour, with a greyish head. Unlike other fruit bats, they prefer to roost alone in thick vegetation. Their sparse yellow to green spots on their wings and ears helps to camouflage them when they wrap themselves in their wings.
At night they fly rapidly and with great maneuverability just above or below the forest canopy, making a distinctive, high-pitched whistling call. Mating occurs from July to September and a single young is born after a gestation period of 3-3.5 months.
This species is moderately common in the northern part of their range in Queensland, but is listed as vulnerable New South Wales.
This bat has snow-white fur and a contrasting yellow nose and ears. Their endearing complexion along with their unusual roosting habits makes them a favorite among bat enthusiasts!
These bats are one of only a few known worldwide to construct their own roosts. Most bats rely on existing structures, natural or otherwise, or simply roost beneath tree bark or on branches, concealed in the foliage. Honduran white bats however construct their own shelter by biting the side veins extending out from the midrib of the large leaves of the Heliconia plant, causing them to fold down to form a ‘tent’. While we understand that this must be the way the bats make their shelter from observing the tent construction over several days, hardly anyone has actually observed the bats in the act of modifying a leaf.
Being able to make your own roost is a handy skill when roosts are unavailable or uncommon in tropical forests. They also provide advantages in enabling the bats to be more easily alerted to approaching predators, such as snakes or primates. Tents are often high off the ground with few or no obstructions directly below, providing a clear view of approaching predators and allowing them to make a quick escape. Tent-making bats are also sensitive to disturbance of the surrounding foliage, which could signal an approaching predator, or an excited bat ecologist trying to capture the bats roosting beneath the leaf!
The social system of these little fruit-eating bats is also quite interesting. Honduran white bats are polygynous, meaning that they form harems, made up of a single male and several adult females. The roosting group is typically made up of five to 15 bats and the male rigorously defends his harem or tent against intruders and challengers. How long these groups stay together and how the group members are related to each other, are factors that are largely unknown.
These bats are truly some of the most beautiful you will ever see and I was luckily enough to find some in the rainforests of Costa Rica. They are also found in Honduras, Nicaragua and Panama but unfortunately they are listed as Near Threatened on the IUCN Red List due to their significant decline (but at a rate of less than 30% over ten years) due to human population density and habitat conversion.