Product Code Database
The numbat (; binomen: Myrmecobius fasciatus), also known as the noombat or walpurti, is an insectivore marsupial. It is diurnal animal and its diet consists almost exclusively of .
The species was once widespread across southern Australia, but is now restricted to several small colonies in Western Australia. It is therefore considered an endangered species and protected by conservation programs. Numbats were recently re-introduced to fenced reserves in South Australia and New South Wales. The numbat is the faunal emblem of Western Australia.
The species is not closely related to other extant marsupials; the current arrangement in the order Dasyuromorphia places its Monotypic taxon with the diverse and carnivorous species of Dasyuridae. Genetic studies have shown that the ancestors of the numbat diverged from other marsupials between 32 and 42 million years ago, during the late Eocene.
Two subspecies have been described, but one of these—the rusty coloured Myrmecobius fasciatus rufus Finlayson, 1933,—has been extinct since at least the 1960s, and only the nominate subspecies ( M. fasciatus fasciatus) is extant. The population described by Finlayson occurred in the arid central regions of South Australia, and he thought they had once extended to the coast. The separation into subspecies was not recognised in the national census of Australian mammals, following W. D. L. Ride and others. As its name implies, M. fasciatus rufus had a more reddish coat than the surviving population. Only a very small number of fossil specimens are known, the oldest dating back to the Pleistocene, and no other species from the same family have been identified.
The following is a phylogenetic tree based on Mitochondrion genome sequences:
Placement of the family within the order of dasyuromorphs may be summarised as
The common names are adopted from the extant names at the time of English colonisation, numbat, from the Nyungar language of southwest Australia, and walpurti, the name in the Pitjantjatjara dialect. The orthography and pronunciation of the Nyungar name is regularised, following a survey of published sources and contemporary consultation that resulted in the name noombat, pronounced noom'bat.
Other names include banded anteater and marsupial anteater.
Akin to other myrmecophages, the numbat has a long and narrow tongue coated with sticky saliva produced by large submandibular glands. A further adaptation to the diet is the presence of numerous ridges along the soft palate, which apparently help to scrape termites off the tongue so they can be swallowed. The digestive system is relatively simple and lacks many of the adaptations found in other insectivorous animals, presumably because termites are easier to digest than ants, having a softer exoskeleton. Numbats are apparently able to gain a considerable amount of water from their diets, since their lack the usual specialisations for retaining water found in other animals living in their arid environment. Although the numbat finds termite mounds primarily using scent, it has the highest visual acuity of any marsupial, and, unusually for marsupials, has a high proportion of in the retina. These are both likely adaptations for its diurnal habits, and vision does appear to be the primary sense used to detect potential predators.
Today, numbats are naturally found only in areas of eucalypt forest, but they were once more widespread in other types of semiarid woodland, spinifex grassland, and in terrain dominated by Dune. There are estimated to be fewer than 1,000 left in the wild.
After measures aimed at excluding feral cats, the number of numbats trapped during annual population surveys in the Dryandra Woodland had increased to 35 by November 2020, after recording just 10 in 2019 and 5 in 2018. There had not been so many numbats recorded since 36 were recorded in the 1990s.
The species has been successfully reintroduced into three fenced, feral predator-proof reserves in more varied environments; Yookamurra Sanctuary in the mallee of South Australia, Scotia Sanctuary in semi-arid NSW, and Western Australia's Mount Gibson Sanctuary. Reintroduction began at large fenced reserves in Mallee Cliffs National Park in NSW in December 2020, and on South Australia's Eyre Peninsula in 2022.
Attempted reintroductions of the species to fenced reserves in two other areas – one in the South Australian arid zone, near Roxby Downs, and the other in the northernmost part of its former range, at Newhaven Sanctuary in the Northern Territory – both failed.
There are plans to reintroduce the species to a managed and semi-fenced area of the southern Yorke Peninsula in South Australia, as part of the Marna Banggara (formerly Great Southern Ark) project.
Adult numbats are solitary and territorial; an individual male or female establishes a territory of up to 1.5 square km (370 acres) early in life, and defends it from others of the same sex. The animal generally remains within that territory from then on; male and female territories overlap, and in the breeding season, males will venture outside their normal home ranges to find mates.
While the numbat has relatively powerful for its size, it is not strong enough to get at termites inside their concrete-like mounds, 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 midmorning to midafternoon; in summer, it rises earlier, takes shelter during the heat of the day, and feeds again in the late afternoon. Numbats can enter a state of torpor, which may last up to fifteen hours a day during the winter months.
At night, the numbat retreats to a nest, which can be in a log or tree hollow, or in a burrow, typically a narrow shaft 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 accessing the burrow.
Numbats have relatively few vocalisations, but have been reported to hiss, growl, or make a repetitive 'tut' sound when disturbed.
The young are long at birth. They crawl immediately to the teats and remain attached until late July or early August, by which time they have grown to . They are long when they first develop fur, and the patterning of the adult begins to appear once they reach . The young are left in a nest or carried on the mother's back after weaning, becoming fully independent by November. Females are sexual maturity by the following summer, but males do not reach maturity for another year.
and the following day:
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.
The population recognised and described as a subspecies by Finlayson, M. fasciatus rufus, is presumed to be extinct. The first record of the species described it as beautiful, and its popular appeal led to its selection as the faunal emblem of the state of Western Australia and initiated efforts to conserve it from extinction.
The two small Western Australia populations apparently were able to survive because 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.
Since 2006, Project Numbat volunteers have helped to save the numbat from extinction. One of Project Numbat's main objectives is to raise funds that go towards conservation projects, and to raise awareness through presentations held by volunteers at schools, community groups and events.
Numbats can be successfully reintroduced into areas of their former range if protected from introduced predators.
|
|
