MARSUPIAL MOLES: Notoryctemorphia

PHYSICAL CHARACTERISTICS

Marsupial moles, also called blind sand burrowers, are unusual and rarely seen animals found in Australia. Marsupial moles are about 4 to 6 inches (10 to 15 centimeters) long and weigh only 1 to 2.5 ounces (40 to 70 grams). They have fine golden fur, and are shaped like flattened cylinders.

The body of the marsupial mole shows many adaptations that allow it to live almost its entire life underground. These moles have five toes on each foot. On the front feet, toes three and four are enlarged and have triangular, spade-like claws that are used for digging. The animals have no functional eyes. Only a dark spot marks where the remains of an eye can be found under the skin. In addition, marsupial moles have no external ears, although they do have ear openings under the fur, and it is believed that they can hear. Five of the animal's seven neck vertebrae, neck bones, are fused, or joined together, probably to strengthen the head so that it can push through sand.

A horny shield somewhat like a thick fingernail protects the nose. The nose openings or nostrils are small slits, probably to prevent them from filling with sand as the animal digs. Female marsupial moles also have a backward-opening pouch in which they carry their young. Again, this is probably an adaptation so that the pouch does not fill with sand as they move forward. The tail is short, less than 1 inch (2.5 centimeters), hairless, and covered with a leathery skin and ends in a hard, horny knob.

Genetic studies show that marsupial moles are not closely related to any other Australian marsupial. In 1987 a fossil marsupial mole was found at Riversleigh, an area that was known to be a rainforest habitat millions of years ago. Scientists think that this fossil mole used its broad claws to burrow through leaves and moss on the forest floor. When the climate changed and Australia became drier, these claws allow it to adapt to living in sand.

GEOGRAPHIC RANGE

Marsupial moles live in the deserts of Western Australia, South Australia, the Northern Territory and southwestern corner of Queensland.

HABITAT

These moles live in sandy desert regions and seem to prefer sand plains near seasonal rivers or sand ridges where spinifex grass grows.

DIET

Marsupial moles hunt and feed underground, digging their food out of the sand. They are insectivores, eating mainly ants, termites, and insect larvae (LAR-vee). They have also been known to eat seeds and small lizards. Marsupial moles kept in captivity and fed on the surface take their food underground to eat it.

BEHAVIOR AND REPRODUCTION

Marsupial moles are active under the ground both day and night. They "swim" or burrow through sand rapidly. They normally tunnel about 4 to 8 inches (10 to 20 centimeters) under the surface. However, they occasionally dig down to depths of more than 8 feet (2.5 meters). When moving through sand, the mole uses its wide front claws to shovel soil backward under its belly. Then the hind feet push together to propel the body forward. These moles do not leave the burrows. The sand fills in the area behind them as they move.

Marsupial moles seem to appear on the surface more often after a heavy rain, although some scientists question if they actually appear more often or if their tracks are simply more noticeable in damp sand. On the surface, they move slowly with a shuffling side-to-side gait and drag their tail, leaving a distinctive pattern of parallel lines. They move only short distances before re-entering the sand. The speed with which they dig allows them to avoid most predators, animals that hunt them for food.

Almost nothing is known about marsupial mole reproduction. Females have two teats, nipples, in a backward-opening pouch.

MARSUPIAL MOLES AND PEOPLE

Aboriginal (native) people call the southern species of marsupial mole Arra-jarra-ja or Kakarratul and the northern species Itjari-itjari. These people probably ate moles when they could catch them, but because of the difficulty in hunting them, they were not a major food source. Today marsupial moles are of interest to scientists and the public mainly because of their rarity and interesting adaptations to life underground.

BRRR—IT'S COLD

Marsupial moles are used to living where it is hot. They begin to shiver when the temperature drops to 59°F (15°C) and die of hypothermia, a condition where core body temperature decreases, soon afterwards. Most marsupial moles kept in captivity have died because people did not understand that they need to be kept at temperatures of 73 to 81°F (23 to 27°C) to survive.

CONSERVATION STATUS

Although the distribution and population size of marsupial moles is not known, both species, the northern marsupial mole and the southern marsupial mole, are considered Endangered, facing a very high risk of extinction in the wild in the near future. Marsupial moles receive legal protection from the Australian government. In an effort to learn more about the marsupial mole population, the University of Western Australia supports a program for the public to report sightings of these animals.

SOUTHERN MARSUPIAL MOLE (Notoryctes typhlops): SPECIES ACCOUNT

Physical characteristics: The southern marsupial mole, sometimes called the greater marsupial mole or just the marsupial mole, has a total head and body length of 3.5 to 7 inches (9 to 18 centimeters) and a 1-inch (2-centimeter) tail. It weighs about 1.2 to 2.5 ounces (35 to 70 grams). Southern marsupial moles have short legs, spade-like claws on the front feet, and flat nose shields. They also lack eyes and external ears.

Geographic range: Southern marsupial moles are found in Western Australia, the southern Northern Territory, and northwestern South Australia. The northern part of its range may overlap with the range of the northern marsupial mole.

Habitat: Southern marsupial moles live underground in sandy plains and sand ridges.

Diet: This species eats mostly insects and insect larvae.

Behavior and reproduction: Marsupial moles "swim" rapidly through sand, living most of their lives underground. They appear to live alone. Almost nothing is known about their reproductive pattern.

Southern marsupial moles and people: Southern marsupial moles have little practical value to humans, but they are a symbol of the rare and unusual animals of Australia. Their bodies are an excellent example of adaptation to their environment.

Conservation status: These moles have been listed as Endangered, facing a very high risk of extinction, even though little is known about their abundance. It appears, however, as if their numbers are declining. One reason may be compacting of the soil they live in by vehicles or livestock. ∎

FOR MORE INFORMATION

Books:

Menkhorst, Frank. A Field Guide to the Mammals of Australia, 2nd ed. Oxford, U.K.: Oxford University Press, 2001.

Nowak, Ronald M. Walker's Mammals of the World. Baltimore: Johns Hopkins University Press, 1995.

Web sites:

Withers, Philip, and Graham Thompson. "Marsupial Moles (Notoryctes)." University of Western Australia Zoology Department. http://www.zoology.uwa.edu.au/staff/pwithers/marsupialmole/Default.htm (accessed on June 30, 2004).

University of Michigan Museum of Zoology. "Order Notoryctemorphia." Animal Diversity Web http://animaldiversity.ummz.umich.edu/site/accounts/information/Notoryctemorphia.html (accessed on June 30, 2004).