Quokka

Name and taxonomy

The name quokka comes from a Noongar word, probably gwaga or gawaga. Noongar people also call the animal ban-gup or bungeup. Other English names are short-tailed wallaby and short-tailed pademelon, and German speakers say Kurzschwanzkänguru. The species name brachyurus is thought to come from the Greek for a short tail.

The quokka belongs to the kangaroo family, Macropodidae, in the order Diprotodontia. It sits alone in the genus Setonix, with no subspecies. A Dutch mariner, Samuel Volckertszoon, reported a wild cat on Rottnest in 1658. In 1696 Willem de Vlamingh took the animals for giant rats and named the island 't Eylandt 't Rottenest, the rat nest island. The French artist Charles-Alexandre Lesueur drew two living quokkas after French ships called at Rottnest in 1801 and 1803. The type locality is King George Sound, near Albany.

Evolution and relatives

The quokka's closest relatives are the other wallabies and kangaroos of the family Macropodidae. Like them it has strong hind legs, a pouch and a hopping gait. It carries 22 chromosomes. It is among the smallest wallabies, and its build recalls the pademelons and rock wallabies. The sources used here give no fossil record for the genus, so its deeper history is thought to follow that of the wallabies in general.

Appearance

The quokka is a thickset wallaby with a short face, a broad head and small rounded ears. Head and body measure 40 to 54 centimetres, and the tail adds 25 to 30 cm, short for a macropod. Adults weigh 1.6 to 4.2 kilograms. Males weigh 2.7 to 4.2 kg and females 1.6 to 3.5 kg. Body size falls with latitude.

The fur is thick, coarse and grizzled grey-brown on the back, and paler below. The head, neck and shoulders sometimes carry a reddish wash. The tail is dark, thinly furred and sometimes paler beneath. The nose is bare and black, the back is rounded, and the forearms are short. Despite its kangaroo shape, it climbs shrubs and small trees up to 1.5 metres to reach leaves. Unlike most wallabies it has colour vision, which probably helps it spot predators.

Habitat and range

Wild quokkas live only in the far south-west of Western Australia. The largest population lives on Rottnest Island off Perth. A smaller one lives off Albany, on Bald Island. Neither island has foxes or cats. On the mainland, scattered groups survive between Perth and Albany in forest and in coastal heath, mostly inside reserves and national parks. One colony shares Two Peoples Bay Nature Reserve with the critically endangered Gilbert's potoroo. In late 2024 a new population turned up in the Perth Hills, and its location is kept secret.

Mainland quokkas need dense ground cover: swamps, thickets, rushes and sedges. They keep to country with more than 700 millimetres of rain a year, and most now live where it passes 1,000 mm. They favour scrub that burned 10 to 19 years earlier, when the regrowth is richest. On Rottnest they use everything from semi-arid scrub to cultivated gardens and the settlement itself. By day they sleep under the spiky shrub Acanthocarpus preissii, which keeps larger animals out.

At settlement the species covered about 41,200 square kilometres of the south-west. By 1992 the mainland range had shrunk to about 17,800 km2. GBIF holds records from 5 countries, a count that includes zoo animals.

Diet and feeding

The quokka is a browser that eats leaves and stems from a wide but selective set of shrubs. Mainland studies recorded 29 plant species in the diet, though 11 shrubs made up 90% of it. On Rottnest the diet covers 40 species, with saltbush and other succulents dominant in summer. Grasses, forbs and sedges fill in as the seasons turn, and fresh growth is preferred. A small mallow, Guichenotia ledifolia, is a favourite food.

An adult male eats about 32 to 45 grams of dry food a day. Leaves supply most of the water it needs, so it drinks little for much of the year. Even so, Rottnest animals walk up to 2 kilometres to freshwater soaks in the dry months. It swallows food, brings it back up and chews the cud, much like a cow. It also eats seeds, berries and fruit, and it has been seen eating snails. On Rottnest it scavenges from rubbish dumps and from visitors, though human food makes it ill.

Behaviour and social life

The quokka is nocturnal. It wakes in the late afternoon, feeds through the night with peaks in the early evening and before dawn, and returns to shelter. Heavy rain and bright moonlight keep it under cover. On the mainland it moves along well-worn runways through dense vegetation and seldom strays far from cover. It is highly sedentary, and a home range covers about 5 hectares for either sex.

On Rottnest each animal uses a few resting sites and forages in the open 50 to 600 metres away. Ranges overlap, and more than 100 animals may gather at a freshwater soak. Animal Diversity Web describes mainland colonies of one to two dozen and island groups of up to 150. Even so the quokka is not very social, and it often rests and feeds alone. Males fight to hold resting sites, and a hierarchy forms with the heaviest males on top. A resting site may be shared by several females, or by a male with one or two females.

Young animals mostly settle within 100 metres of where they were born, though one moved 900 m. Adults occasionally travel up to 10 kilometres. A mother chased by a predator may drop her joey from the pouch. The joey squeals, which may draw the predator while the mother escapes.

Communication and senses

Little has been published on how quokkas communicate. The quokka has colour vision, which is unusual among marsupials and probably helps it see predators. Males signal rank by fighting and by chasing rivals from resting sites and from females. A female accepts a male by staying with him and grooming him, and she rejects one by hopping away. A dropped joey calls out, which suggests sound plays a part in the bond between mother and young.

Reproduction and life cycle

Females mature at about nine months and males at 13 months. The mating system is promiscuous, and a female in oestrus may mate with up to five males. A dominant male guards a receptive female by chasing off rivals, and he loses interest after mating. Copulation lasts 2 to 4 minutes, sometimes up to 11, and may repeat up to nine times with one male. Females choose too: they refuse some males, or hop away when the guard is distracted.

Gestation lasts about 27 days, and the female bears a single joey, rarely twins. She mates again shortly after the birth, and the new embryo pauses in diapause. If the pouch joey dies, the embryo resumes growth, and if the joey lives, the embryo is lost. Mainland females breed all year and may raise two young a year. On Rottnest and Bald Islands most births fall between January and March, and females rest for much of the year.

The joey stays in the pouch for about six months. It then follows its mother as a young-at-foot and is weaned at around eight months. Some young stay near the mother until 19 to 20 months. A female produces about 17 joeys in her lifetime. Wild quokkas live 8 to 15 years, typically about 10, and one captive animal reached 13.8.

Predators and threats

On the mainland the introduced red fox is the chief predator, and it reached the south-west in the 1930s. Feral and domestic cats, dogs, dingoes and birds of prey also take quokkas. On Rottnest, snakes are the only predator. Bald Island has none.

Habitat loss is the other great threat. Clear-fell logging, farming, housing, and the draining and burning of swamps have all cut the mainland range. Feral pigs degrade the wet thickets that remain. A 2015 bushfire near Northcliffe killed about 90% of a population of 500. Quokkas recover slowly after severe fire and take years to return to burnt ground.

Late summer brings hunger on Rottnest, as plants dry and surface water vanishes, and many juveniles die. Summer also brings high rates of Salmonella infection. Falling rainfall and rising temperatures since the 1970s squeeze the wet habitat the species needs. One severe climate scenario predicts the loss of all suitable range by 2070.

Population and conservation

The IUCN lists the quokka as Vulnerable, and Australia lists it the same way. Rottnest Island held an estimated 8,000 to 12,000 animals in 2007. Bald Island holds 600 to 1,000. The mainland holds about 4,000, nearly all in groups of fewer than 50. One declining group of more than 700 lives between Nannup and Denmark, in the southern forest.

In the early 1900s the quokka was common enough to be hunted and treated as a farm pest. The sharpest decline ran from the 1930s to the 1990s. Mainland groups are now small, isolated and low in genetic diversity. Some have grown where foxes are controlled, and pig control runs in some areas. A recovery plan exists, and the species breeds well in captivity.

On Rottnest the problem may be the reverse: quokkas could be so abundant that they stop native plants from regrowing. Numbers there swing with the seasons.

Relationship with humans

Quokkas show little fear of people, and on Rottnest they walk right up to visitors. That confidence made the quokka selfie a social media trend in the mid-2010s. Chris Hemsworth, Roger Federer and Margot Robbie have all posed with one, and tourist numbers rose afterwards. The smile is an accident of facial structure, not an expression.

It is illegal to handle a quokka, and feeding is discouraged because chips and bread cause dehydration and malnutrition. The Rottnest Island Authority issues $300 fines, and cruelty carries up to a $50,000 fine and five years in prison. A few dozen people a year are bitten, most of them children. Wild quokkas carry Salmonella at high rates in summer, so contact brings some risk. Perth Zoo, Taronga Zoo and Adelaide Zoo keep the species, and one study found that animals in walk-through enclosures hid from visitors.

In culture and myth

The Noongar people of the south-west named the animal, and their word became the English name. The Dutch, the first Europeans to meet it, took it for a rat and left that mistake in the name Rottnest. Lesueur's drawing of two live quokkas, made after the French visits of 1801 and 1803, is one of the earliest European images. Web sources retell a Noongar story in which a lazy kangaroo was shrunk into the quokka as a punishment. The tale is thought to be poorly attested.

In the 2010s the quokka became an internet symbol of happiness and positivity. Its face now sells Rottnest Island, and tourism there grew on the strength of it. Spirit-animal blogs link the quokka with joy and resilience, and some add Dreamtime or Celtic connections that probably have no basis.