Caring for tree-rats

The black-footed tree-rat is one of Australia’s largest rodents. This nocturnal mammal is found only in Australia’s tropical north. Their lifestyle is similar to possums. 

Read more about rescuing and releasing animals in the Northern Territory (NT).

You need a permit to care for injured or rescued wildlife.

Background

Tree-rats live in eucalypt forest and woodland, preferring areas with tall eucalyptus trees with a dense under storey of shrubs and trees.

While tree-rats mainly live in trees, they spend time on the ground to forage. They nest in tree hollows and in pandanus when hollows are not available. 

They can travel large distances to forage and their home territories are large. They are very secretive and territorial.

Black-footed tree-rat

The black-footed tree-rat (Mesembriomys gouldii) has large ears and a long tail with a brush of white hair at the tip.

Their greyish-brown coat is coarse and shaggy and their belly is creamy white. Their hind feet are black and strong with well-developed pads and strong claws.

Their incisors continue to grow throughout the animal’s life and are covered in a layer of tough enamel. Wear on these incisors forms a sharp leading edge, which is ideal for a diet of tough, woody plant material.

They breed throughout the year, usually with a litter size of one to three.

The young are born with upper incisors and their eyes closed. They weigh around 34g. They become adults at about 80 days old, with females weighing around 580g and males around 650g.

The black-footed tree-rat is considered vulnerable in the Northern Territory (NT). If you see this species, report it to Parks and Wildlife immediately.

Housing

Black-footed tree-rats should be kept in a quiet, secure spot away from family pets and loud noise. This includes general household noise, traffic, domestic animals and construction.

House unfurred young tree-rats in a lined, insulated enclosure with a heat source. As they grow, they’ll need a larger enclosure to climb in and forage. 

Tree-rats wean at around 42 days old, when they weigh about 400g. Once weaned, they can be housed in an outdoor wire-mesh enclosure. Adults should be housed separately, unless it is a mother with young.

The enclosure should do all of the following:

  • be similar to the natural environment of a tree-rat
  • contain different-sized tree trunks
  • have a mix of stable and flexible climbing structures, such as wobbly branches and rope
  • have a natural floor with leaf litter and grasses
  • have places to put native food, such as branches with flowers and fruit
  • have nesting areas, including horizontal and vertical logs - the open end of the log should be higher to encourage upward movement when the animal is climbing out
  • have room to climb and forage, and places to hide food
  • have shelter to protect from Wet Season weather, heavy sun, or wind and temperature extremes
  • have private areas for sleeping and feeding
  • be secure so domestic pets and other predators can’t get in
  • include items to stimulate the tree-rats
  • be cleaned daily and disinfected between inhabitants.

Feeding

Tree-rats will eat a range of food. It’s important to give them branches and hard-shelled nuts to gnaw on to keep their teeth healthy.

Feeding orphaned tree-rats

Orphaned tree-rats need high-protein, high-fat milk as they grow quickly. 

Di-Vetelac - follow the directions on packaging - mixed with 1ml of egg yolk and a pinch of high-protein powder is a good formula for hand-raising black-footed tree-rat young.

The young of this species often show a strange behaviour during feeding.They stretch their head backwards with mouth gaping and extend the forearm with fingers splayed. The reason for this is unclear. You must stop feeding during this behaviour.

When the young weigh 90g you can feed them solids such as mealworms, dry dog kibble, fruit, vegetables and nuts in shells. 

Pandanus nuts and grevillea flowers are a favourite.

Feeding adult tree-rats

Black-footed tree-rats prefer to feed from containers large enough for them to sit in. 

Once they’re feeding well, you can put their food in smaller bird 'D' feeders. Place feeders throughout the enclosure to encourage the tree-rats to move around.

Black-footed tree-rats will hide food. It’s important they have some hollow logs for this.

You can any of the following foods:

  • pigeon mix
  • muesli
  • unshelled raw nuts that are not salted, roasted or otherwise processed
  • mealworms
  • fruits - apple, banana, grapes and lychees
  • vegetables - carrot, sweet potato and corn on the cob
  • sugarcane - to encourage chewing
  • cracked grain.

Native foods and browse include any of the following: 

  • pandanus nuts
  • fruits and flowers - green plum, cocky apple, sandpaper figs, cluster figs, bush apple and woollybutt flowers
  • seeds from carpentaria, woollybutt, stringy bark and ghost gums.

Tree-rats need fresh water daily. Keep water in the shade and off the ground.

Capture and handling

Handle tree-rats as little as possible.

Adult black-footed tree-rats deliver a substantial bite. You should wear gloves when handling tree-rats to lower the risk of injury. 

Transport

Tree-rats can be moved in a small pet pack with towels or blankets. A strong cardboard box may work for short distances. Calico bags can also be used if turned inside out to avoid loose threads.

Make sure animals don't overheat during transport.

Enrichment

Enrichment is the set of things you can do to help an animal regain natural behaviour and be ready for release to the wild.

You can use all of the following enrichment strategies to prepare a tree-rat for release:

  • provide pandanus trees for nesting
  • provide hollow logs
  • provide climbing structures
  • scatter crickets, mealworms, woodies, seeds and nuts through the enclosure
  • hang food through the enclosure to encourage foraging
  • allow leaf litter to build up for insects to hide and live in
  • put rotting tree trunks and logs on the ground for insects and foraging opportunities
  • provide termite mounds placed in the enclosure
  • provide hard chewing material such as unshelled nuts and sugarcane
  • put in large, horizontal hanging logs - rope both ends for secretive feeding and food storing in the hollow
  • provide water in hanging rat drinkers.

How to tell a tree-rat is ready to release

A tree-rat is ready to release when it is showing the following behaviours:

  • looks for natural foods such as pandanus and other nuts, seeds, flowers and insects
  • is arboreal - lives in trees
  • uses a number of nesting sites
  • is active at night
  • stores food
  • showing less abnormal behaviour, such as pacing, and more natural behaviours
  • is coping with change
  • shows improved physical fitness.

Contact

For more information contact Wildlife Operations in your region.

Last updated: 27 June 2017