Numbat
| Numbat | ||||||||||||
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Numbat ( Myrmecobius fasciatus ) |
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| Systematics | ||||||||||||
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| Scientific name of the family | ||||||||||||
| Myrmecobiidae | ||||||||||||
| Waterhouse , 1841 | ||||||||||||
| Scientific name of the genus | ||||||||||||
| Myrmecobius | ||||||||||||
| Waterhouse , 1836 | ||||||||||||
| Scientific name of the species | ||||||||||||
| Myrmecobius fasciatus | ||||||||||||
| Waterhouse , 1836 |
The numbat ( Myrmecobius fasciatus ), also known as the antbuckler , is a small Australian marsupial from the order of the predator-like (Dasyuromorphia). Because of its different anatomy and way of life, it is assigned to its own family, Myrmecobiidae. Its diet consists almost exclusively of termites , which it digs up with strong claws and catches with a worm-shaped tongue. Above all, the reenactment by the red fox introduced by humans in Australia has led to the numbat disappearing from large parts of its former range and can only survive with intensive protective measures.
features
Appearance
Its shape, its pointed snout and the striking stripes make the Numbat unmistakable among Australia's mammals. The basic color of the fur in the only subspecies still existing today is red-brown in the front and dark brown to black in the back. The underside is whitish. Four to eleven white transverse ligaments run across the back of the back, becoming paler and more indistinct towards the front. The long tail is brown in color, but can appear gray due to numerous white hairs. A black stripe runs from the base of the ear to the muzzle and frames the eye. There is a whitish stripe underneath.
The coat is thin and consists of short, stiff hair. The hair on the tail is much longer. If the tail is erected, the bristly hairs can be erected so that the impression of a bottle brush is created.
The front back is the highest point on the body, while the head and back are lower. The ears are twice as long as they are wide. The eyes are relatively high on the head.
Numbats have five toes on their front legs and four on their hind legs. All toes are armed with strong claws.
The head body length of the numbat averages 27 cm. There is also a 20 cm long tail. The weight is between 500 and 700 grams.
Teeth and tongue
In the shape of the snout, the simplification of the teeth and the length of the tongue, some convergence to other insectivorous mammals ( anteaters , pangolins ) can be recognized. The numbat has numerous teeth that are very reduced in size and appear as simple conical points, some of which barely protrude beyond the gums. Because not all teeth always develop, the number of teeth varies between individuals and sometimes even between the left and right side of the jaw of the same animal.
Most of the time, however, the following tooth formula appears:
| 4th | · | 1 | · | 3 | · | 4-5 | = 48-52 |
| 3 | · | 1 | · | 3 | · | 5-6 |
The numbat always has more than seven postcanine teeth (molars and premolars). This is unique among land mammals.
The tongue of the numbat is long and worm-shaped. The greatly enlarged salivary glands produce a sticky saliva that covers the tongue and ensures that food sticks to it. Thirteen or fourteen ridges run across the roof of the mouth, along which the tongue is drawn when it is drawn in, in order to strip off the stuck insects.
Sense organs and glands
The Numbat mainly uses the senses of sight and smell. The smell is used to track down the food in the ground, the eyes to detect enemies at an early stage. What is striking is the relative complexity of the eyes, which is unparalleled among marsupials. The retina is dominated by cones , the pupils are immobile - both typical characteristics of diurnal animals. No other marsupial examined so far has a sharper sense of sight than the numbat. The field of view covers an angle of 240 ° horizontally, but is quite limited vertically.
On the chest, Numbats have a round, almost hairless, orange-brown area that is occupied by scent glands , which presumably serve to mark territory. Females also have an anal gland , while males do not.
metabolism
At higher mammals with comparable life often shows a decreased metabolism, since the high fraction indigestible chitin in the prey ensures that the body is supplied less power. However, this is not the case with the Numbat. Its body temperature of 34.1 ° largely corresponds to that of other marsupials. Like all predator-like species, the numbat occasionally decays into a torpor , which can last up to fifteen hours and in which the body temperature can drop to 19 °.
distribution and habitat
The earlier distribution of the numbat can be reconstructed on the basis of subfossil finds, travel reports, Aboriginal traditions and the documented locations of museum specimens.
Accordingly, the Numbat once lived in the southern part of Western Australia , in South Australia with the exception of the Nullarbor Desert , in the central deserts and in the far west of New South Wales (see also map under threats and protection ). Since the arrival of the first European settlers, this territory has shrunk dramatically until there were only two populations left:
- Dryandra Woodland , a 28,000 hectare nature reserve in the middle of farmland, 170 km east of Perth
- Perup Nature Reserve , a 52,000 hectare protected area near Manjimup
Recently, releases have created nine more populations, seven in Western Australia, one in South Australia and one in New South Wales. Some of these protected areas are fenced in to keep foxes away.
The Numbat was once at home in a wide variety of habitats. It occurred both in the sandy desert and in the Spinifex savannah, in the Mulga bush as well as in the eucalyptus forest . The remaining populations now only live in forests.
Way of life
activity
The numbat is the only exclusively diurnal marsupial in Australia. There is a connection here with its prey, the termites, which are also active during the day. In summer, mornings and late afternoons are the most active times, and the midday heat is sheltered under construction. In winter, however, the Numbat is active in the middle of the day. Rainy weather is always avoided.
A self-dug earth cave can serve as a building, but sometimes a hollow trunk is sufficient. There is a big difference here between forest and free-range populations: the latter naturally rely on burrows, while the forest-dwelling numbats build few or no caves. A self-dug structure has an entrance 8 cm in diameter. This passage leads over a length of 1 m to a chamber with a diameter of 15 to 23 cm, which is 10 to 60 cm below the surface. A Numbat has several burrows in its action area.
Numbats are loners with a large action area of up to 50 hectares. They usually move forward in a slow pace, stopping repeatedly to sit on their back legs and scout the area. If threatened, however, they can run away at a speed of 32 km / h. The escape leads to a construction nearby.
food
Numbats feed exclusively on termites . Thus, the German name “Ameisenbeutler” is misleading, because ants are only eaten unintentionally; the only ants whose remains were found in numbat droppings were species that predated termites and were therefore eaten with them. In the areas now inhabited by Numbats, the termite species Coptotermes acinaciformis and Amitermes obeuntis are the most important prey animals. With every gram of organic food, a numbat also consumes 0.33 grams of soil, which also sticks to the tongue.
The numbat's claws are strong, but not strong enough to break open a termite mound. Therefore, only those termites that are around the hill in the branching underground passages are eaten. To do this, the numbat sits on its hind legs and digs up the earth with its front claws.
In captivity, a numbat ate 10,000 to 20,000 termites a day. Small termites are swallowed, only particularly large ones are chewed with the teeth beforehand.
Reproduction
The gestation period is fourteen days. Two to four young are born between January and April. Usually the litter includes the full number of four pups, corresponding to the four existing teats.
The teat area of the female is surrounded by curly, yellowish hair that stands out clearly against the white of the abdomen. One bag is completely missing. Thus, when the 2 cm young boys have crawled to their teats, they have to hold on to their hair. They stay on the teats for up to six months. Numbat's milk is particularly rich in oleic acid . This parallel to the unrelated ant urchins seems to be related to the similar diet.
Towards the end of July, when the young are three inches long, they let go of their hair. In the shelter of a burrow, the mother continues to suckle them. When the building is changed, the mother carries them with her on her back. At the end of September the cubs also walk around independently outside, and in November they leave their mother.
Females are sexually mature in the first year of life, males only in the second. There is no information about the lifespan in the wild, in the zoo Numbats live to be five to six years old.
Enemies and parasites
The most important predator of the Numbat today is the red fox . Domestic cats also hunt down Numbats. Thus, two robbers brought in by humans are the Numbat's worst enemies. In addition, birds of prey and snakes were detected as predators, especially the species bands Habicht , Sydney Sperber , rabbit Adler , wedge-tailed eagle , hawk Hawk and diamond Python . Dingoes or bag martens have never been observed to hunt numbats, but it is suspected.
A scratchworm of the species Mulusentis myrmecobius , which is only known from Numbat, occasionally attacks the animals and has occasionally led to their death. Termites are obviously the intermediate hosts of these worms, which means that they are ingested with the food.
Infections with mycobacteria are known of numbats in captivity, as is common in captive marsupials . These can cause purulent lesions that can lead to death.
Systematics and names
External system
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Predator-like cladogram
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The Numbat is so unique in anatomy and way of life that no close relatives can be identified. Therefore it is assigned to its own family Myrmecobiidae. Molecular genetic analyzes place the numbat at the base of the predator-like species , so that the common clade of predator and bag wolves can be seen as a sister group .
Internal system
In 1923 a second Numbat species was described as Myrmecobius rufus ; In 1933, Hedley Herbert Finlayson classified this as a subspecies of the well-known numbat and thus named it Myrmecobius fasciatus rufus (English Rusty Numbat , = "rust-red numbat"). This subspecies had a strong red fur on the back, which turned into a lighter brown towards the back; the underside was beige and not white. The last representative of this subspecies was found around 1950 at Warburton . It is said that there were still sightings until the 1960s, but today the red subspecies is most likely extinct.
The nominate form Myrmecobius fasciatus fasciatus , the only subspecies still alive today, once inhabited western Western Australia, while the red subspecies was native to eastern Western Australia and the other Australian states.
Tribal history
Fossil finds are hardly available. Numbat fossils were found only three times and all of them belong to the species living today. Two are from the Pleistocene , one from the Holocene . One of the Pleistocene finds comes from the Nullarbor Desert, an area where, as far as we know today, Numbats never lived in historical times.
Names
The Numbat was described in 1836 by George Robert Waterhouse under the name Myrmecobius fasciatus , which is still valid today . Initially, English terms such as Banded Anteater ("Striped Anteater"), Marsupial Anteater ("Pouch Anteater") or White-banded Bandicoot ("White Stripe Bandikut") were common, in German the name "Ameisenbeutler". In the meantime, the name Numbat, taken from an Aboriginal language, has established itself, at least in English. Incidentally, the Aborigines have several names for this animal, as there are also a variety of languages. Other names are, for example, noobat , nombat , nyoombot , waihoo , weeu , walpurti or mutjurarranypa .
Threat and protection
The decline of the numbat probably began immediately after the start of European colonization in Australia. The Numbat initially disappeared from the easternmost parts of its former range. He was last seen in New South Wales in 1857. In South Australia there was proven evidence until the 1920s and alleged until the 1940s. In the central deserts, the Numbat disappeared around 1960, then also in most of Western Australia, so that in the 1980s only the two small reserves in Dryandra Woodland and Perup Nature Reserve were left.
Although several reasons have been cited for the decline in numbat, the dramatic decline in populations during the 20th century appears to be mainly due to a single cause: the red fox abandoned by humans in Australia . The fox gradually advanced further and further west, and wherever it made its home the numbat died out shortly afterwards. Survival in Dryandra and Perup can also be traced back to the fact that fox extermination programs were implemented in these areas and to this day care has been taken to keep foxes away. The success was a steady increase in Numbat populations until 1990.
After the low point in 1980, efforts were also made to reintroduce the numbat in parts of its former range. The beginning was made in 1985 in the Boyagin Nature Reserve in Western Australia, after all foxes had previously been eradicated as planned. After the successful reintroduction, further such attempts were made, so that today Numbats are also found in these reserves:
- Boyagin Nature Reserve , Western Australia
- Dragon Rocks Nature Reserve , Western Australia
- Batalling State Forest , Western Australia
- Tutanning Nature Reserve , Western Australia
- Yookamurra Sanctuary , South Australia
- Scotia Sanctuary , New South Wales
Some of these are completely fenced in to prevent foxes from entering. The Perth Zoo plays a role in the reintroduction, where Numbats are constantly being prepared for release.
The reintroductions led to the IUCN 1996 "critically endangered" the Numbat the status ( endangered ) to "endangered" ( vulnerable ) back classified. However, the population in Dryandra Woodland subsequently fell from 600 to 50 individuals. The reasons for this slump are unclear and are still being researched. In contrast, the stocks in the Perup Nature Reserve have remained stable. In 2008 the IUCN raised the endangered status back to "highly endangered".
It is estimated that between 500 and 600 numbats live in the wild today.
Individual evidence
- ↑ a b c d e f g Cooper 2011, p. 130
- ↑ a b c d Nowak 1999, p. 65
- ↑ a b c Cooper 2011, p. 131
- ↑ a b c Cooper 2011, p. 132
- ↑ Friend & Thomas 2003, p. 453
- ↑ a b Cooper 2011, p. 134
- ↑ a b c d Cooper 2011, p. 136
- ↑ a b c Cooper 2011, p. 137
- ↑ a b c Cooper 2011, p. 135
- ↑ a b c Nowak 1999, p. 66
- ↑ a b c Cooper 2011, p. 133
- ^ William T. Gaynor, Debra V. Cousins & J. Anthony Friend: Mycobacterial Infections in Numbats (Myrmecobius fasciatus) . In: Journal of Zoo and Wildlife Medicine 1990, Vol. 21, No. 4, pp. 476-479
- ↑ a b c Cooper 2011, p. 129
- ↑ L. Fumagalli, C. Moritz, P. Taberlet & JA Friend: Mitochondrial DNA sequence variation within the remnant populations of the endangered numbat (Marsupialia: Myrmecobiidae: Myrmecobius fasciatus) . In: Molecular Ecology 1999, No. 8, pp. 1545-1549
- ↑ a b c Cooper 2011, p. 138
- ↑ a b c d Myrmecobius fasciatus in the IUCN Red List of Threatened Species . Retrieved January 21, 2012.
literature
- Christine Elizabeth Cooper: Myrmecobius fasciatus (Dasyuromorphia: Myrmecobiidae) . In: Mammalian Species 2011, No. 43, pp. 129-140
- Ronald M. Nowak: Walker's Mammals of the World . Johns Hopkins University Press 1999. ISBN 0801857899 .
- J. Anthony Friend & Neil D. Thomas: Conservation of the numbat (Myrmecobius fasciatus) . In: Menna Jones, Chris Dickman, Mike Archer (Eds.): Predators with Pouches - The biology of carnivorous marsupials . CSIRO Publishing 2003. ISBN 0643066349
