The Numbat (Myrmecobius fasciatus), also known as the Banded Ant Eater, is a marsupial found in Western Australia. Its diet consists almost exclusively of termites. Once widespread across southern Australia, the range is now restricted to several small colonies and it is listed as an endangered species. The Numbat is an emblem of Western Australia and protected by conservation programs.

Description

The Numbat genus Myrmecobius is the sole member of the family Myrmecobiidae; one of the three families that make up the order Dasyuromorphia, the generalised marsupial carnivores. The species is also known as the walpurti.

The Numbat is a small, colourful creature between 35 and 45 cm (13-18") long, with a finely pointed muzzle and a prominent, bushy tail about the same length as its body. Colour varies considerably, from soft grey to reddish-brown, often with an area of brick red on the upper back, and always with a conspicuous black stripe running from the tip of the muzzle through the eyes to the bases of the small, round-tipped ears. The underside is cream or light grey; weight varies between 280 and 550 grams.^[2]

Unlike most other marsupials, the Numbat is diurnal, largely because of the constraints of having a specialised diet without having the usual physical equipment for it. Most ecosystems with a generous supply of termites have a fairly large creature with a very long, thin, sticky tongue for penetrating termite colonies, and powerful forelimbs with heavy claws.^[3] Like other mammals that eat termites or ants, the Numbat has a degenerate jaw with non-functional teeth, and is unable to chew. Nonetheless, numbats do have a similar dental formula to many other marsupials:

The species is not closely related to other extant marsupials; the current arrangement in the Dasyuromorphia order places its monotypic family with the diverse and carnivorous species of Dasyuridae. A closer affinity with the extinct thylacine, contained in the same order, has been proposed.

Diet

Numbats are insectivores and eat an exclusive diet of termites. An adult Numbat requires up to 20,000 termites each day. The only marsupial that is fully active by day, the Numbat spends most of its time searching for termites. It digs up termites from loose earth with its front claws and captures them with its long sticky tongue. ^[4]

Ecology and behaviour

Adult numbat at Perth Zoo

Adult Numbats are solitary and territorial; an individual male or female establishes a territory of up to 1.5 square kilometres (370 acres)^[3] early in life, and defends it from others of the same sex. The animal generally remains within that territory from that time on; male and female territories overlap, and in the breeding season males will venture outside their normal home range to find mates.

While the Numbat has relatively powerful claws for its size,^[3] it is not strong enough to get at termites inside their concrete-like mound, and so must wait until the termites are active. It uses a well-developed sense of smell to locate the shallow and unfortified underground galleries that termites construct between the nest and their feeding sites; these are usually only a short distance below the surface of the soil, and vulnerable to the Numbat's digging claws.

The Numbat synchronises its day with termite activity, which is temperature dependent: in winter, it feeds from mid-morning to mid-afternoon; in summer, it rises earlier, takes shelter during the heat of the day, and feeds again in the late afternoon. Despite its Banded Anteater name, ants are not a major component of their diet.

At night, the Numbat retreats to a nest, which can be in a hollow log or tree, or in a burrow, typically a narrow shaft 1-2 metres long which terminates in a spherical chamber lined with soft plant material: grass, leaves, flowers and shredded bark. The Numbat is able to block the opening of its nest, with the thick hide of its rump, to prevent a predator being able to access the burrow.^[5]

Conservation status

Trap set to monitor the wild population in the Dryandra Woodland

Until European colonisation, the Numbat was found across most of the area from the New South Wales and Victorian borders west to the Indian Ocean, and as far north as the southwest corner of the Northern Territory. It was at home in a wide range of woodland and semi-arid habitats. The deliberate release of the European red fox in the 19th century, however, wiped out the entire Numbat population in Victoria, NSW, South Australia and the Northern Territory, and almost all Numbats in Western Australia as well. By the late 1970s, the population was well under 1,000 individuals, concentrated in two small areas not far from Perth, Dryandra and Perup.

The first record of the species described it as beautiful;^[6] its appeal saw it selected as the faunal emblem of the state of Western Australia and initiated efforts to conserve it from extinction.^[5]

It appears that the reason the two small Western Australia populations were able to survive is that both areas have many hollow logs that may serve as refuge from predators. Being diurnal, the Numbat is much more vulnerable to predation than most other marsupials of a similar size: its natural predators include the Little Eagle, Brown Goshawk, Collared Sparrowhawk and Carpet Python. When the Western Australia government instituted an experimental program of fox baiting at Dryandra (one of the two remaining sites), Numbat sightings increased by a factor of 40.

An intensive research and conservation program since 1980 has succeeded in increasing the Numbat population substantially, and reintroductions to fox-free areas have begun. Perth Zoo is very closely involved in breeding this native species in captivity for release into the wild. Despite the encouraging degree of success so far, the Numbat remains at considerable risk of extinction and is classified as an endangered species.^[1]

Discovery

Richter's Myrmecobius fasciatus, 1845

The Numbat first became known to Europeans in 1831. It was discovered by an exploration party who were exploring the Avon Valley under the leadership of Robert Dale. George Fletcher Moore, who was a member of the expedition, recounted the discovery thus:

"Saw a beautiful animal; but, as it escaped into the hollow of a tree, could not ascertain whether it was a species of squirrel, weasel, or wild cat..."

and the following day

"chased another little animal, such as had escaped from us yesterday, into a hollow tree, where we captured it; from the length of its tongue, and other circumstances, we conjecture that it is an ant-eater—its colour yellowish, barred with black and white streaks across the hinder part of the back; its length about twelve inches."^[6]

The first classification of specimens was published by George Robert Waterhouse, describing the species in 1836 and the family in 1841. Myrmecobius fasciatus was included in the first part of John Gould's The Mammals of Australia, issued in 1845, with a plate by H. C. Richter illustrating the species.

See also

• List of adaptive radiated marsupials by form

References