Generally, the Quokka has a typical appearance for a wallaby: short, extremely coarse and thick fur, which is grey-brown overall with lighter under part; short tail, which is mostly without hair; and hair of its feet, which extend to the claws. Willem de Vlamingh, an early Dutch explorer, described this animal as 'a kind of rat, as big as a common cat'. The scientist first saw the Quokka on an island off the mouth of the Swan River, which he named after this animal - Rottnest (or 'rat nest') Island.
This animal is endemic to Rottnest Island, located off Perth (Western Australia). The Quokkas also occur on the mainland, where the animals almost exclusively inhabit areas with dense vegetation around swamps, where they find shelter during hot days. The preferred environment of the Quokkas is humid areas with dense vegetation. However, they are able to live in different habitats, including seasonally arid and harsh environment of Rottnest Island.
These highly sociable and communicative animals gather into small family groups. The leader of a Quokka group is the dominant male. Quokkas are non-territorial: there have been known cases of up to 150 individuals having overlapping home ranges and, generally, sharing them without conflicts. However, they occasionally do engage in fights, especially to get the most sheltered spots during hot days. These nocturnal animals spend most of the hot days resting. They typically find shelter in shade of trees, and are known to use the same resting spot every day. They feed by night, browsing for food and moving through high grass in order to remain unspotted. To move around quickly, they usually hop on their hind legs. As opposed to kangaroos and large wallabies, Quokkas do not use their tail to support them when moving slowly. Being terrestrial animals, Quokkas, however, are capable of climbing up to 1.5 m when looking for food.
Quokkas are likely to have polygynous mating system, where each male mates with a number of females. The breeding season takes place during the cooler months, in January - March. Gestation period lasts for one month, yielding a single baby, which lives in the pouch of its mother for up to 30 weeks. After that, the joey begins to come out of the pouch and gradually starts exploring its surroundings. However, the young remains close to its mother and keeps on feeding upon maternal milk for over 8 - 10 weeks. Sexual maturity is reached by one year old.
Presently, the primary concern to the population of this species is recreational development of Rottnest Island, which is the main range of the Quokka. As a result, the animal suffers from loss of its natural habitat as well as the risk of catching a human disease.
According to the IUCN Red List, the total population size of the Quokka is estimated to be 7,850-17,150 mature individuals, including specific populations in following areas: Rottnest Island - 4,000-8,000 animals; Bald Island - 500-2,000 Quokkas; Northern Jarrah forest - 150 animals; Southern forests - 2,000-5,000 individuals; South Coast - 1,200-2,000 animals. Currently, Quokkas are classified as Vulnerable (VU), and their numbers are decreasing.
The Quokka serve as prey for the red foxes and dingoes, their natural predator.