Big bag junk
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Large bag-gullet ( Notoryctes typhlops ) |
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| Notoryctes typhlops | ||||||||||||
| ( Stirling , 1889) |
The large pouch mole ( Notoryctes typhlops ) is one of two species from the family of the pouch mole (Notoryctidae).
Discovery story
Even before it was first described, the Aborigines had known the Great Bag Muck for thousands of years. The first specimen accessible to biologists was found in 1888 by W. Coulthard in the Northern Territory . It reached Edward Charles Stirling , director of the South Australian Museum, in such a decayed state that he was unable to locate a pouch. Therefore the species was not counted among the marsupials at first .
Nineteenth-century scientists believed that marsupials and higher mammals evolved from the same ancestors and were looking for a living missing link . Since the bag mole is similar to the gold mole in Africa , some scientists assumed that the two families were related, which proves their theory. But this was only the case until better preserved specimens appeared that clearly showed the bag.
description
The large bag junk is between 12.1 and 15.9 centimeters in size and weighs between 40 and 70 grams. The tail reaches a length between 2.1 and 2.6 inches long. The body is covered by a short, smooth fur; it is usually creamy white, but the iron oxides in the soil make it mostly reddish-brown in color. The nose and mouth are brownish-pink in color. The species has no vibrissae . The conical head merges directly into the body. The short legs are very strongly developed and two tens each have large shovel-like claws. Since the dentition varies from individual to individual and the tooth roots of the molars are only one third of their length, it is believed that the species cannot feed on hard food. Parts of the back, rostrum and tail are not covered by fur and the skin is very horny. Since the species spends most of its life underground, it has no optic nerves whatsoever. The eyes have a layer of pigment that is likely remnants of the retina . The two lacrimal glands and the Jacobson organ are very pronounced. It is believed that the tear glands serve the purpose of cleansing and keeping the nose and Jacobson organ moist. The ears are covered by fur and have no auricle. The animals are able to hear sounds in the low frequency range. The nostrils are small vertical slits that are located just below the shield-like rostrum. The brain is very poorly developed. The scent glands and the sense of smell are very pronounced. The sense of smell seems to play an important role.
Adjustments
The large bag mole does not have a constant body temperature, it fluctuates between 15 and 30 ° C. It shares this characteristic with many other underground mammals, such as: B. the desert gold mole . Its metabolism is not very low, although the metabolic rate in animals living underground is about 60 times that of animals living above ground. The large bag mole is very well adapted to an underground life. Although it is very small and lives underground, where it is cooler than on the surface, it does not seem to be adapted to life in the desert.
behavior
Some of the behavior of the pouch mole is known from field studies. Behavioral research on captured animals is only possible to a limited extent, as the animals usually die after a month in captivity.
Behavior on the surface
As has been observed in captured animals, the pouch gull goes to the surface to forage. The animals leave the ground only for a short time and bury themselves again after a few meters. It has also been observed that the animals mainly come to the surface after downpours or during the cold season. The animals sleep underground. It has also been observed at times that they remain on the surface for a few hours without moving. On the surface, the animals move in a tortuous way, using their front legs to drag their bodies across the ground. They push each other forward with their hind legs. This way they can only move slowly.
Digging behavior
The Large Bag Mud does not build permanent tunnel systems because it closes most of the tubes behind it. It looks like he's swimming through the sand. Its tunnels extend 20 to 100 centimeters, rarely up to 250 centimeters. The temperature difference to the surface can be between 15 ° C in winter and 35 ° C in summer. As has been observed in captured animals, the great bag mole seems to regulate the temperature of its burrow by digging different depths.
Social behavior
Little is known about the social and mating behavior of the mating gull. He seems to be a loner. There is no evidence of large structures in which several animals could live. It is also not known how the two sexes find each other to mate. It is believed, however, that this is done using their highly developed sense of smell. Communication between the individual animals seems to take place via low-frequency sounds.
nutrition
The feeding habits of the mucosa are largely unknown. It appears to be an insect eater, although the consumption of seeds and small lizards has also been observed. His favorite food seems to be beetle larvae. Since the great pouch mullet's underground way of life is very energy consuming, it seems unlikely that it will seek its prey underground.
distribution and habitat
The distribution area includes the desert areas of Western Australia , northern South Australia and the Northern Territory . The species prefers to live in sandy hills and areas that are overgrown by plants of the genus Spinifex .
Danger
The species was in 1996 in the Red List of the World Conservation Union IUCN as ( "high risk" Endangered ) rated. However, since little is known about the Baggy Litter, the real threat is difficult to assess. As a result, no categorization has been carried out since 2008 due to a lack of sufficient data ( data deficient ). The importation of cats and foxes as well as the use of pesticides is demonstrably reducing the population.
literature
- C. Groves, Wilson, DE, Reeder, DM, Mammal Species of the World , Johns Hopkins University Press 2005
- Philip Whitfield, The Simon & Schuster Encyclopedia of Animals , Marshall Editions Development Limited, New York 1998
- John Benshemesh, Ken Johnson, Predators with pouches: the biology of carnivorous marsupials , CSIRO Publishing, Melbourne 2003
- Ken Johnson, The mole who comes from the sun , Wildlife Australia Spring, 1991
- Graham Thompson, Blind Diggers in the Desert , in Nature Australia 26, 2000
- Ken Johnson, Dan Walton, Fauna of Australia v 1B Mammalia , Australian Government Publishing Service, Canberra 1987
- D. Howe, Observations on a captive marsupial mole, Notoryctes typhlops , in Australian Mammalogy 1, 1973
- KA Johnson, The mammals of Australia , New Holland Publishers Pty Ltd., Sydney 1998
- K. Winkel, Diet of the Marsupial Mole, Notoryctes typhlops , in Australian Mammalogy 11, 1988
- David Pearson, Marsupial Moles pop up in the Great Victoria and Gibson Deserts , in Australian Mammology 22, 2000
- Rachel Paltridge, Occurrence of the Marsupial Moel (Notoryctes typhlops) remains in the faecal pellets of the cats, foxes and dingoes in the Tanami Desert in Australian Mammalogy 20, 1999
Web links
Individual evidence
- ↑ Notoryctes Typhlops in the endangered Red List species the IUCN 2010. Posted by: Dickman, C., Burbidge, A., Aplin, K. & Benshemesh, J., 2008. Accessed on March 14 of 2010.