Marsupial Mole
Tagged: animal, animals, cat, insect, mammalNotoryctes typhlops
Of all Australia’s mammals, the marsupial moles of the western desert are certainly among the more unusual species. Since they normally spend almost their entire lives buried in the sandy soil, they are also among the least well understood. Before declaring an animal Endangered, the IUCN normally needs convincing scientific evidence that the species is likely to become extinct unless the causes of the declining numbers are removed. In most cases the evidence for a species’ decline is not difficult to come by-we can often easily see there are fewer individuals than there once were. Occasionally, however, there are exceptions; in the case of the marsupial moles of Australia the IUCN agreed to classify the species as Endangered even though most scientists who have tried to study the species admit that they have no idea how many marsupial moles there may be. Marsupial moles are extraordinary for many reasons. In lifestyle and appearance they are very similar to African golden moles; but other than the fact that both are mammals, they are only distantly related. The similarities are a stunning example of what biologists call convergent evolution, where two completely different types of animal evolve into very similar forms because it is the best way of dealing with similar challenges of habitat or way of life. In the case of the marsupial mole the challenge is how to live buried in the desert sand.
Two of a Kind
The marsupial mole (sometimes also called the southern marsupial mole) has been known about since the 19th century. However, individuals are rarely seen-which is not surprising given the animal’s way of life. In 1920 a new sort of marsupial mole was discovered close to Eighty Mile Beach on the northwestern coast of Western Australia. This variety, called the northern marsupial mole, was a little smaller than the southern marsupial mole, and it had a differently shaped nose-shield and tail. Whether the northern marsupial mole qualifies as a separate species is the subject of a debate that is unlikely to be resolved, since the animals are so hard to find. However, from time to time specimens of the southern marsupial mole are discovered. People finding the moles are usually puzzled enough to contact a museum or university, and dead or dying specimens have been collected at a rate of five to 15 animals every 10 years. The real challenge is to find and study a living marsupial mole of the northern variety. Scientists have spent years searching the deserts, enlisting the support of local people living in remote Aboriginal communities. In 1998 two schoolboys found and captured a living specimen of the northern marsupial mole, which ended up at the Museum of Western Australia. It did not adapt to life in captivity and died after about eight weeks, having not eaten well in all that time. Marsupial moles do occasionally come to the surface, usually after rain. When they emerge, their bodies leave distinctive furrows in the sand, with marks either side where they have used their legs to haul themselves along. Further proof that the moles are around can be found by taking core samples of firm sand and looking for the oval-shaped areas of looser material that show a mole has passed through. Scientists have tried burying sound-sensitive microphones in the sand to detect passing moles. The problem with all such techniques is that, while they show that there are moles around, they do not give any idea how many there are. Until researchers can get some idea about population size, it is very difficult to prove what position the species is in. There is no shortage of goodwill toward the moles, since they do not appear to damage human activities such as farming. They have been killed out of curiosity or for their silky fur, but are not deliberately hunted. The marsupial moles’ chief problem is likely to be changes in their habitat due to controlled burning of bush and grass to create grazing pastures. Predation by introduced species, such as cats, could be a problem too. A high proportion of fox droppings have been found to contain marsupial mole remains, ,thus proving that the marsupial mole’s predators are better at finding them than people are.
Statistic
Marsupial mole (southern marsupial mole)
Notoryctes typhlops
- Family: Notoryctidae
- World population: Unknown and almost impossible to estimate
- Diet: Insect grubs, particularly larvae of beetles and moths
- Breeding: Unknown
- Distribution: Northwestern Australia
- Habitat: Desert burrows
- Size: Length head/body: 4-6 in (10-16 cm); tail: 1 in (2.4 cm). Weight: 1.2-2.5 oz (35-70 g)
- Form: Flat-bodied animal with palegolden fur; very short legs; spadelike front feet; no functional eyes, ear hole hidden in fur; nose has tough, horny shield, tail short and stubby. Female has a pouch opening to rear
- Related endangered species: Northern marsupial mole (Notoryctes caurinus) EN, although it may not qualify as a separate species. Its scientific classification is the subject of a debate
The marsupial mole has fine, sandy-colored silky fur and shovellike hands, which it uses to “swim” through sand. It can be found up to 5 feet (1.5 m) below the surface. It has no eyes or obvious ears, which would quickly clog with sand, and the female’s pouch opens toward the rear, so it does not get full of sand.
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