The Feathertail Glider: this tiny marsupial is the world's smallest gliding mammal, measuring just 6.5-8cm long (not including the tail)
The scientific name of this species is Acrobates pygmaeus (literally "pygmy acrobat") but it's commonly known as the feathertail glider, the pygmy glider, or the flying mouse.
This is the smallest gliding mammal in the world, as its head and body have a combined length of just 6.5-8cm, and its tail measures another 7-8cm long. The tail is fringed on each side with a row of long, stiff hairs that give it a feather-like appearance -- a feature that is not found in any other mammal. This feather-shaped tail acts as a rudder, allowing the tiny marsupial to steer and brake as it glides.
Feathertail gliders struggle to stay warm in harsh conditions, and they must enter a state known as torpor in order to preserve their energy, as this article describes:
A fascinating feature of these tiny mammals is that because they are so small, they have trouble staying warm when it is cold or when there is a food shortage; like the Sugar glider, they enter a state known as torpor.
This means that for short periods, their breathing slows down, and the animal becomes unresponsive; the body temperature drops almost to that of its surroundings. This state is not to be mistaken for hibernation, which is for much longer periods and is not known to occur in marsupials.
Groups of A. pygmaeus have been observed in practically any available enclosed space, from hollow tree trunks to telephone interchange boxes to bird nests or possum dreys. They form spherical nests (dreys) of vegatation, usually eucalypt leaves, bark and tree-fern fiber. They have been found in groups of up to 20 individuals, but these are not considered stable associations. It is believed that communication between mother and young is through a number of high-frequency sounds and marking with urine.
Feathertail gliders are found only in mainland Australia.
Moonlit Sanctuary: Narrow-Toed Feathertail Gliders
Australian Museum: The Feathertail Glider
Animal Diversity Web: Acrobates pygmaeus
Mammalian Species: A. pygmaeus
Wildlife Information, Rescue, and Education Service: The Feathertail Glider
Wildlife Preservation Society of Queensland: Feathertail Gliders
Rares Foundation: Husbandry Guidelines for Feathertail Gliders (PDF)