The eastern quoll (Dasyurus viverrinus, formerly known as the eastern native cat) is a medium-sized carnivorous marsupial (dasyurid), and one of six extant species of quolls. Endemic to Australia, they occur on the island state of Tasmania, but were considered extinct on the mainland after 1963. The species has been reintroduced to fox-proof fenced sanctuaries Victoria in 2003 and to the Australian Capital Territory in 2016.
Taxonomy
The eastern quoll is a member of the family Dasyuridae, which includes most carnivorous marsupials. Its species name, viverrinus, indicates it is "ferret-like". There are no recognised subspecies.
Description
Eastern quolls are about the size of a small domestic cat, with adult males measuring in total length, including the tail, and having an average weight of . Females are significantly smaller, measuring , including a tail, and weighing around . They have a tapering snout, short legs, and erect ears. They can be distinguished from all other species of quoll by the presence of only four toes, rather than five, on the hind feet, lacking the hallux.
They have a thick coat covered by white spots, that can be either light fawn or near-black, with off-white underparts stretching from the chin to the underside of the tail. Both fawn and black individuals can be born in the same litter, although in surviving populations the former are about three times more common than the latter. The spots are in diameter, and are found across the upper body and flanks, from the top of the head to the rump, but, unlike some other species of quoll, do not extend onto the tail.
Females possess a relatively shallow fur-lined pouch formed by lateral folds of skin. The pouch becomes enlarged during the breeding season, and includes six to eight teats, which only become elongated and functional if one of the young attaches to them, regressing again after they leave the pouch. As with all quolls, the penis of the male bears an unusual fleshy appendage. The large intestine of eastern quolls is relatively simple, having no caecum, and not being divided into a colon and rectum. An unusual feature of eastern quolls is the presence of an opening connecting the ventricles of the heart in newborn young, in addition to that connecting the atria found in all marsupials. Both openings close after a few days.
Distribution and habitat
The eastern quoll was formerly found across much of southeastern mainland Australia, from the eastern coasts of South Australia, through most of Victoria, to the mid-north coast of New South Wales. The species was formerly abundant around Adelaide, particularly the Adelaide Hills, with a 1923 newspaper article noting its rapid decline and presumed extinction in the area during the preceding ten years.
It likely became functionally extinct across its entire mainland range by the early 1960s, but remains widespread but patchy in Tasmania and Bruny Island. Within Tasmania, eastern quolls inhabit rainforest, heathland, alpine areas, and scrub below . However, they prefer dry grassland and forest mosaics, bounded by agricultural land, particularly where pasture grubs are common.
Behaviour
The eastern quoll is a solitary predator, hunting at night for its prey of insects, small mammals, birds, and reptiles. They have been known to scavenge food from the much larger Tasmanian devil. Although the majority of their diet consists of meat, they also eat some vegetable matter, including fruit during the summer, and grass year-round. The eastern quoll is itself prey for Tasmanian devils and masked owls.
Eastern quolls are nocturnal, and spend the day resting in dens, although they may also use natural rock crevices or hollow tree trunks. The dens often consist of no more than a simple, blind-ending tunnel, but are sometimes more complex, including one or more nesting chambers lined with grass. Each individual uses a number of dens, usually no more than five, which it alternates between on different days.
Eastern quolls are solitary, and tend to avoid one another, but can form loose 'neighbourhoods'. Home ranges are typically around for females, and for males, with the latter increasing dramatically during the breeding season. Territories are scent marked, although scats are distributed randomly, rather than placed at specific latrines. Adults also ward off intruders by hissing and making coughing sounds, and also make a sharp shriek that may be an alarm call. If intruders fail to leave quickly, then aggressive action escalates to chasing and wrestling with jaws while standing on their hind legs. Mothers and young have softer calls they use to maintain contact.
