HONEY POSSUM: Tarsipedidae

PHYSICAL CHARACTERISTICS

Honey possums are very small and highly specialized marsupial mammals. Despite their name, honey possums do not actually make or eat honey—instead, they have unique physical features that help them to feed primarily on the pollen and nectar from flowers. They are very small and have long tongues to pull the nectar or pollen out from inside a flower. Their heads are long and tapered, and they are covered in coarse, short hair. Except for three black stripes down the middle of their back, their coloring is a grayish brown.

Male honey possums weigh only 0.24 to 0.38 ounces (7 to 8 grams). Female possums weigh slightly more, between 0.28 and 0.56 ounces (8 to 16 grams). From the tip of their nose to the end of their body (excluding the tail) they are only between 2.6 and 3.5 inches (6.5 to 9 centimeters) long.

Honey possums have long tails, as long or longer than their bodies. They use this tail to help them climb along branches between flowers. The tip of the tail is prehensile, meaning that the honey possum can use it to grasp objects. It is almost hairless, which also helps to improve its grip. Honey possums are often seen hanging upside down by their tails. They also have very long tongues, which they can extend beyond their mouth even further than the length of their head. This helps them to retrieve their food from flowers. Their paws have four toes. The bones of the middle two toes on the back paws are fused (attached) but have separate claws that are used for grooming. Other toes are clawless.

GEOGRAPHIC RANGE

Honey possums live in a very small region in the southwestern tip of Australia.

HABITAT

The honey possum lives on uninhabited sandy beaches where the kinds of flowers that they feed on bloom almost all year round.

DIET

Even though they are called honey possums, these animals do not eat honey. They feed upon the nectar and pollen from the flowers of plants such as myrtles (MER-tuhlz), proteas (PRO-tee-ahz), and banksias (BANK-see-ahz) that grow on the coast of southwestern Australia. Their teeth, which are stubby and short, are not used to chew or bite. In order to get the pollen and nectar, honey possums use their long tongue and tapered head to poke into the flowers. The end of their tongue is like a brush, and they use it to pull the food into their mouth. In order to maintain themselves, honey possums must consume large amounts of their sugary food and spend most of their time searching for flowers.

BEHAVIOR AND REPRODUCTION

Because they require a large amount of energy to keep warm, honey possums spend most of their time in search of food. They are nocturnal, which means they are most active at night, and sleep during the day. Honey possums live alone and sleep in holes of trees or nests that birds have abandoned. While the flowers from which they eat pollen or nectar bloom most of the year, sometimes there is a scarcity of food. During this time, honey possums often gather in large groups and curl up together. They become inactive, as if they are hibernating. Their heart rate slows and their body temperature drops in order to conserve energy. When more food is available, the honey possums become active again.

To get from flower to flower, honey possums run quickly along the sandy ground and climb very skillfully up branches in order to reach the blossoms. They use their long tails to grasp branches in case they lose their balance. Often they hang upside down in order to reach a flower. Once they have reached the flower, they use their front toes to pull it apart and then push their snout inside. Their long tongues can extend far into the flower and scrape out the pollen inside.

Honey possums are marsupial mammals, which means that they do not have a well-developed placenta. The placenta is an organ that allows the mother to share food and oxygen with developing offspring in her uterus (womb) during pregnancy. As a result, their young are born underdeveloped and need to continue to grow in their mother's pouch for some time after birth before they can survive in the outside world.

Honey possums live only for a year or two, but they reproduce almost continuously. After only six months, both male and female honey possums are able to produce offspring. After about a two-month pregnancy, the mother gives birth. The newborns then spend another two months inside her pouch attached to one of her four nipples. At birth, the young weigh only 0.00002 ounces (0.0005 grams), and they are the smallest of all known mammals. Inside the pouch they grow to 0.09 ounces (2.5 grams). Their eyes open, and they grow hair.

The mother usually mates shortly after the litter (a group of young born at the same time) is born and enters her pouch. Because of this, she is able to give birth to another litter as the first litter is leaving her pouch. After a litter leaves the pouch, they spend a week or two following their mother around and even riding on her back. They are then ready to leave and begin looking for food on their own. A female will usually give birth to two litters, or eight young, but she will not often live long enough to give birth to a third litter.

HONEY POSSUMS AND PEOPLE

Honey possums have little direct relation to humans, although they do help to spread flowers along the coast because of their pollen diet. Despite their nocturnal lifestyle, which makes them hard to find, honey possums are also popular with ecotourists. Ecotourists are people who want to observe nature without disturbing it.

EVOLVING ALIKE

Even though monkeys and honey possums are not related, and they are so different in size, they share many characteristics. For example, honey possums have long tails, which they use for grabbing and balancing on branches like monkeys. Both monkeys and honey possums have toes that are good for grasping and climbing. When two animals are not related by evolution but develop similar characteristics, scientists call this "convergent evolution." Since both monkeys and honey possums needed to be able to climb efficiently, they have evolved similar features to help them.

CONSERVATION STATUS

In 1992, much of the habitat and food supply of the honey possum was disappearing because humans were developing their habitat with little regard to this small animal. Today, with increased awareness, the number of honey possums has rebounded and they are not considered threatened.

FOR MORE INFORMATION

Books:

Robinson, Hannah. Australia: An Ecotraveler's Guide. New York: Interlink Books, 2003.

Steiner, Barbara A. A Field Guide to the Mammals of Australia. Oxford, U.K.: Oxford University Press, 2001.

Triggs, Barbara. Tracks, Scats and Other Traces: A Field Guide to Australian Mammals. Oxford, U.K.: Oxford University Press, 1996.

Web sites:

Australian Association for Environmental Education. "Case Study 3—Honey Possums and Wildflowers." https://olt.qut.edu.au/udf/aaee/gen/index.cfm?fa=displayPage&rNum=475152 (accessed on June 30, 2004).

The University of Michigan Museum of Zoology. "Tarsipes rostratus." http://animaldiversity.ummz.umich.edu/site/accounts/information/Tarsipes_rostratus.html (accessed on June 30, 2004).

Watson, Ian, and Craig Owen. "Honey Possum." Quantum, ABC Television. http://www.abc.net.au/quantum/s244451.htm (accessed on June 30, 2004).