Montshire Minute: Australian Wildlife

Originally aired during the week of September 14, 1998

Monday

In Sydney Australia, swimmers, bicyclists and track athletes have been on display for the entire world to see during the summer Olympiad. Australia also has perhaps the most unique flora and fauna found on any continent. It is home to creatures like marsupial frogs, saltwater crocodiles and legless lizards. There are animals with names like numbats, jabirus (jab-EAR-oos), and spinifex hopping mice. Why are there so many animals in Australia that can't be found anywhere else? Millions of years ago, the continent broke away from a land mass that included South American and Antarctica. Isolated from other lands, Australian wildlife evolved differently, adapting to the special habitats that emerged on the continent. So pull up a chair, make yourself a vegemite sandwich, and listen in as we explore the natural history of Australia this week!

Tuesday

There's more than meets the eye with lots of Australian wildlife. Take the unassuming echidna (e-KID-na), which looks a bit like an undersized porcupine. The echidna has fur, gives live birth, and nurtures its young with mother's milk like any other self-respecting mammal. But the echidna is also a monotreme - a mammal that lays eggs. Hey, I TOLD you this was no ordinary animal. The baby echidna begins as an egg about the size of a grape, which the mother lays inside her pouch. The egg is incubated for about ten days, then hatches. The tiny hatchling (blind, naked and almost transparent), feeds on the mothers milk. It stays in Mom's pouch for about two months, until if finally develops into recognizable baby echidna. Then, it becomes too prickly for her to carry around. The only other living monotreme is the Duck-Billed Platypus, also native to Australia.

Wednesday

The platypus looks like the result of a "create an animal" contest that went slightly out of control. There's the oversized duck-bill, the webbed feet, the flat, beaver-like tail and the furry, mammalian body. Somehow the pieces don't seem to fit together well. But the platypus, which has been around for millions of years, is perfectly suited to its particular freshwater habitat. The platypus neither sees nor hears very well, but its bill is equipped with a special organ capable of finding worms and small crustaceans it feeds on. The platypus will dive to the bottom of a pool or streambed, pulling itself down with its powerful webbed feet and steering with its hind legs and tail. It cruises the bottom of the stream, scooping up gravel or sand with its bill, filtering out the pebbles, while storing the good stuff in pouches in its cheeks. The platypus then resurfaces and chews before diving for more.

Thursday

Unlike monotremes, a few species of marsupials survived on other continents outside Australia. The opossum is a common North American marsupial. But nowhere have marsupials thrived as much as they have in "the land down under." The female kangaroo rears her young in a special pouch on her belly. While in the uterus, the embryo receives little or no nourishment from the mother, so young are born in a very underdeveloped state (a newborn opossum is about as large as a honeybee). The tiny infant kangaroo must make a short but harrowing journey from its mother's birth canal to the entrance of the pouch. Mom assists its young only by licking a path in her fur, tracing the correct route. If the embryo falls to the ground, there is little the mother can do to save it. The young kangaroo remains in the pouch to nurse until its development is complete.

Friday

Australia, host of the Olympic games, boasts some of the most ancient animals on earth. In fact, one of our oldest ancestors is alive and well and living "down under." The Queensland lungfish is thought to be about 400 million years old, the oldest surviving vertebrate. Though now an endangered species, this living fossil can still be seen in the freshwater rivers of eastern Queensland. The fish resembles a stout eel with a broad head and a tail, which ends in a point. It grows to be about four feet long and spends its time bottom feeding. The lungfish has tiny holes under its jaw - electro-receptors that can sense the presence of live food, like worms, in the dark. While a lungfish breathes mostly through its gills, it can surface and breathe with its single lung if the water lacks enough oxygen.