Pygmy rock-wallaby, Little rock-wallaby
The nabarlek is a very small macropod that occurs in northern Australia. Its fur is a dull, reddish color with black and light gray marbling, grayish-white on the underside. The tip of its tail is bushy and black. Its fur is short and has a soft, silky texture. Its feet have thickly padded granulated soles in order to grip onto rock, as it uses skin friction instead of large claws for climbing.
Nabarleks inhabit two separate areas in Australia: northwestern Kimberly in Western Australia and the Northern Territory, including the islands of Borda, Augustus, Hidden and Long. They are restricted to granite or sandstone rocky cliffs, hills and gorges.
Habits and lifestyle
Nabarleks are nocturnal and solitary marsupials. They spend their day sheltering in crevices and caves, emerging at night to eat grasses and herbs. They do not move far from the protection of their rock shelter, though at night may travel far while foraging. Marsupials are rarely vocal, and when used, they are primarily for mating, territorial, and female to offspring interactions. Threat calls are screams in response to attack, sneezes in response to the activity of an opponent, coughs are threats responding to an approach, and barks are hesitant calls generally made over long distances.
Diet and nutrition
Nabarleks are herbivores. They feed on grasses and sedges. In the dry season they mostly eat a tough fern which is called nardoo.
Little is known about nabarleks in the wild. Captive females have been observed attacking males after mating by biting the back of the head and neck, as well as kicking, the male risking death if not removed. Breeding is year round. Females produce one offspring in each litter after gestation of about 30 days. Weaning takes place much sooner than in other species of its genus. The joey is weaned after 160 days outside the pouch and within 175 days is independent. Females are mature by 430 days old and males at 2 years old.
The nabarlek is likely under threat of predation from feral cats, grazing by introduced herbivores, and changed fire regimes – particularly the increased frequency of intense wildfires.
Current statistics on population are not known. According to the IUCN Red List resource, the number of nabarlek mature individuals is around 5, 000-10, 000. Currently this species is classified as Endangered (EN) and its numbers continue to decrease.
Being herbivores, nabarleks may have a role in the structuring of plant communities.
Fun facts for kids
- The nabarlek was discovered by a man called Gould in 1842.
- Nabarleks are able swimmers, being able to kick each leg independently in water, whereas on land they are only able to move their hind legs together. They can also swim efficiently in ‘doggy’ paddle style.
- Female nabarlek produce two different types of milk at the same time. One nipple will deliver milk suitable for the developing joey, while the other delivers milk for the joey that has left the pouch.
- Nabarleks are very shy as well as very curious, running for shelter if they can but staying to fight if they need to.
- When sitting still, a nabarlek leans back to balance on its tail, not its hind legs. It will thump with its tail or back legs to warn others of danger.
- This animal has a feature that is unique among marsupials that enables it to better cope with tough, chewy fern. When its molars wear down they move forward so that new molars come through and replace the old, this continuing throughout the animal’s life.