Species profile

Kimberley Rock-rat

Kimberley Rock-rat

Range and abundance

The Kimberley Rock-rat is an endemic of the Kimberley Region of Western Australia. It is entirely restricted to the high rainfall country found along the northwest Kimberley coastline and on offshore islands. It has a highly patchy distribution as it prefers rough country with areas of rock scree and massive boulders. It is locally common in favourable habitat.

Description

The Kimberley Rock-rat is a small active rodent that grows to 12 – 16 cm in body length, sports a 11 – 13 cm tail and averages 120 grams. It has a pelage of cinnamon brown above and white belly below.

Ecology

A specialist of highly dissected and rugged country, the Kimberley Rock-rat is found where rainforest vegetation grows on rocky screes, or where low trees and dense grasses cling to ledges and sprout from within fissures along gorges. Its diet is thought to comprise of a mixture of seeds from perennial grasses and from rainforest plants. Breeding probably occurs year round but populations may fluctuate as abundance of seeds varies throughout the year.

Threats

Major threats to the Kimberley Rock-rat likely include altered fire regimes, livestock grazing and predation by feral cats. Introduced herbivores can degrade rainforest patches by grazing and trampling and thereby allow savanna grasses with high fuel loads to enter. Degraded rainforest patches may be more likely to burn during wildfires that are becoming increasingly intense and frequent in northern Australia. Due to its small size, the Kimberley Rock-rat is at high risk of predation from feral cats. 


What is AWC doing?

AWC is conserving populations of Kimberley Rock-rat on Artesian Range through a program of fire management (prescribed burning) and eradication of feral herbivores. Prescribed burning on Artesian Range is decreasing the incidence and extent of intense late season wildfires that are more likely to burn into rainforest patches, and into gorges were Kimberley Rock-rats live. AWC is encouraging a stable Dingo population on Artesian Range as this may help to reduce feral cat activity. 

Did you know:

Rock-rats (Zyzomys) are a rarely seen group of rodents that are unique to northern and central Australia. As their name suggests, all five species live in rocky - often heavily dissected - or scree sloped terrains. They have uncommonly fragile tails that loose skin very easily, and when damaged may atrophy to leave a stump. It is not unusual to encounter rock-rats with missing or stumpy tails in the wild.