! Giant White-tailed Rat ! Tropical Rainforest Queensland Australia

Giant white-tailed Uromys

Photo: C & D Frith
Australia's Wet Tropics
Rainforest Life

Giant white-tailed Uromys: Uromys caudimaculatus

Other common names for the Giant White-tailed Rat include the Giant Rat, the White-tailed Rat, and the Giant Naked-tailed Rat.
It is a placental mammal
A nocturnal rodent, it is active at night.
The Giant white-tailed Uromys is a propagator for macadamia nuts and rainforest truffles. The rainforest truffles are very important for the root growth of many species of rainforest trees.
The white-tailed Uromys arrived in Australia from Papua New Guinea approximately four million years ago.
They are important components of the rainforest community as they consume seeds and spread fungal spores.
It is preyed upon by pythons, owls and quolls.
In the past, Aboriginal people ate the Giant White-tailed Rat.
There are two races of White-tailed Rats in Australia. One is in the Iron and McIlwraith Ranges, and the other in the Wet Tropics between Cooktown and Townsville. The differences lie in their chromosomes, but they are able to interbreed.

Identifyable characteristics:

Grey-brown dorsal surface, cream underside.
Paws are pale in colour
Long naked tail with a white end.
Weighing up to a kilogram, the Giant White-tailed Rat is the same size as a small domestic cat or a rabbit.

Habitat:

One of Australia’s largest rodents, it is restricted to North Queensland and the Cape York Peninsula
The rodent nests in trees and caves, and, being an efficient climber, is active on the rainforest canopy as well as on the rainforest floor.
During the day, giant white-tailed rats sleep in tree hollows, burrows under logs and in stream banks etc.
As it is an easily adaptable animal, the clearing of rainforest has not affected its numbers, which are said to be secure. It is regarded however as being a protected species by the Queensland government.

Diet:

It will also eat fruit, seeds, fungi, bark, insects, small reptiles, amphibians, crustaceans, birds’ eggs and nestlings.
The Giant White-tailed Rat consumes almost all of the fallen nuts in some regions of the forest. Beneath the rainforest trees, almost every single nut found is likely to have its outside punctured and its inside removed.
The Giant White-tailed Rat is able to break these hard nuts with the use of its constantly growing incisor teeth and very strong jaws. As only a few other animals are able to eat most of these nuts, the Giant White-tailed Rat therefore gains special use of some food sources.
These rats are also well known for their ability to raid campsites and houses. They can cause significant damage – for the early settlers to the region, the rats were constantly disturbing and depleting food stores. This often meant the workers had to go without.
The Giant White-tailed Rat loves to chew all sorts of materials such as plastic, rubber, electrical wires, leather, tin and canvas. They will often bite cans open and consume the contents. Some people even believe the rats can read the labels! They have been known to damage and disable vehicles too by biting through fan belts and water hoses.
The recommended remedy for stopping these rats from assaulting property is live trapping and relocating individuals.

Social Behaviour:

Individuals are generally solitary, territorial and reside in an area for a long period of time.

Viewing Opportunities:

Breeding:

The breeding season starts when the summer rains arrive (October / November).
Giant White-tailed Rats have 2 or 3 (rarely 4) young at a time, and only a 36-day gestation period.
They usually have dens well off the ground in tree hollows or in underground burrows.
These are thought to be lined with vegetation as those of captive animals are lined with materials gathered from outside the cage.

Additional Information:

It is much more attractive than it sounds, with a cute pink face and a happy little jaunt.
They are also quite aboreal and very efficient at gnawing into things, and so it is not uncommon to find coconuts on the lowland beaches with large holes that have been chewed out by these giant rats. (Damon Ramsey BSc.(Zool) Biologist Guide)
Unlike other rats, the Giant White-tailed Rat does not race up tree trunks, although it is an excellent climber. Instead, it propels itself upward with its hind legs and strongly clawed hind feet, grasping with its front feet. This is similar to the climbing techniques of the Tree Kangaroo. Its tail can also twist over a surface and hold on using its rasp-like scales.
They also have similarities to the Striped Possum – both species use their large teeth to tear open rotting logs whilst looking for insect larvae. If a rodent is unable to gnaw, its teeth may eventually grow around into its face and kill the animal. At the back of its mouth, separated from the incisors by a gap, are pairs of molars which are used to grind food.

The Rodents:

These native rats would probably be more popular if they were not referred to as rats, but by other names instead. Melomys is commonly used for example. A tourist meeting a White-tailed Rat for the first time is likely to appreciate its uniqueness more if it is called a ‘Uromys’ rather than a rat.
Other native rodents seen in the Wet Tropics include the Bush Rat, the Cape York Rat and the Prehensile-tailed Rat.
Over half of all mammal species are rodents – worldwide this is about 2000 species that have been described. The group includes squirrels, porcupines, beavers and agoutis.
Most common rats in the wet tropics are either new endemic 'true' rats (Rattus spp) or belong to one of the old endemic groups (Uromyini) which includes the white-tailed rats (Uromys)
The rats in the old endemic group are known as the mosaic tiled rats. This is because the scales on their tails are arranged in an interlocking pattern, with very little overlap, rather like tiles in a mosaic.
By contrast, the scales on the tails of other rats overlap and are arranged in a more ring-like pattern.
The tails of mosaic-tailed rats appear naked, while those of Rattus have visible hairs.