Diversity

By Fran Zak
August, 2003

Our group of traveling teachers visited a variety of Australian habitats, and observed different species of marsupials in each habitat. This account gives an assortment of fascinating marsupials.

sugar glider

Looking just like flying squirrels back home in New Jersey, wild sugar gliders came out every evening to a viewing area at Chambers Rainforest Lodge. They came to lick honey (can you see its tongue?) that had been spread on the tree trunks. They glide from one tree to another using flaps of skin attached to their front legs to form a parachute. I did wonder what it would feel like when she landed tummy-first on a tree trunk after a glide.

padmelons

Pademelons are small kangaroos that are active mainly at night. Pademelons are rather like large rabbits in the way they feed on plants and move about quietly to avoid predators. The wild pademelon family group that I also watched at Chambers Rainforest Lodge had a definite hierarchy and specialized jobs. There were always 3 or 4 sentinels around the edges of the grassy feeding area looking in all directions for potential predators. They waited for signals from the dominant male before they attempted to move from their post. The dominant male also regulated how close every other individual could get to him while he was feeding. If another pademelon gets too close it is chastised by the dominant male. When danger threatened, one or several individuals would stomp their large muscular feet and the entire group would hop off into the shrubs for cover and protection.

I was impressed by the large size of the Eastern gray kangaroos that we saw close-up in the Australia Zoo. When they stood up on their hind legs, they reached almost to my shoulders. Their tails were strong and muscular and their large hind legs allowed them to hop away from danger quickly. We saw these kangaroos in the wild, grazing in herds and leaping across the landscape, sort of like deer. But these kangaroos travel with great speed on only two legs. I've heard that they are good fighters and can be quite dangerous to humans if they are threatened. I got this photo of my friend, Karen, feeding a leucistic kangaroo . Leucistic animals lack pigment, but unlike albinos, they do not have red, unpigmented eyes -- instead, they have various eye colors.

leucistik kangaroo

There are marsupials on other continents, for example "Didelphis" opossums live in eastern USA and many more opossum species are in Central and South America. However, the majority of these unique pouched mammals live in Australia. Many types of marsupials, such as the species called kangaroos and wallabies, are found only in Australia.

This is an interesting study in ecological competition. When Gondwanaland separated into the other continents, such as North and South America, there were no placental mammals to compete with marsupials in Australia, so the marsupials thrived there. When placental mammals arose elsewhere, with advanced survival methods, the marsupials could not compete with them, and their niches were filled by placentals instead. That same process is now occurring in Australia, where housecats and rabbits have been brought in by humans, and they have caused extinctions of many marsupial herbivores and carnivores.

Learn about special animal homes in my next Australia Journal Account #3.

Special thanks to Professional Resources in Science and Mathematics (PRISM) at Montclair State University and Dr. Jackie Willis for making these ecology trips possible and for sharing her wealth of knowledge, her expertise, and her photographs with us.