Down Under!

Environmental Science from Australia

On the left is one of the infamous Cane toads imported to Australia to control the cane beetle, a pest on the sugar cane crop. While it is an effective predator of the beetles in its home territory, about the only thing smaller than it that the cane toads don't eat in Australia is the beetle. It has become a classic case of an introduced 'exotic' species run amok. The cane toads have poison glands behind their heads. One of the victims of the poison has been the crocodiles (such as the salt water crocodile, or 'salty', photographed here at the Sydney Aquarium). So far, only one predator, the bustard, has found an effective way to eat cane toads. The birds flip the toads over onto their backs and peck at their bellies, avoiding the poison glands. However, they have not effectively controlled cane toad populations. Other attempts at biological control in Australia have worked better, such as the virus introduced to control the exploding population of rabbits after their introduction.

On the left is Barron's Falls...at the top of the photo is a small reservoir. The water is diverted into a hydroelectric powerplant. As usual, there are tradeoffs for any type of power. Here, there is a very steep drop which is rather ideal for hydroelectric power generation. Aesthetically, the falls isn't what it used to be, and certainly the ecology of the river that formed this impressive canyon is dramatically changed- though clearly there isn't the problem of blocking fish trying to return to spawning grounds. Of course, this is a renewable power resource, no mining required, no fossil fuel emissions. A good idea? YOu decide. The other waterfall is Bloomfield falls, along the 4-wheel track between Cairnes and Cooktown. There were warning signs about crocodiles there, but the local indigenous people enjoyed swimming there when I visited...no doubt they have a good idea if crocs are in residence at any given time!

Epiphytes are one example of commensalism, where one species benefits, and the other is not (to our knowledge) disturbed in any way. The photo of the sign (and the epiphytes) were taken along the boardwalk on the Skytram that takes you to Barron's Falls outside Cairnes. The kauri tree photos below were taken at a different stop on the Tram. I highly recommend the ride- riding above the rainforest is amazing!

The Kauri tree grows basically straight up, trying to compete for the light. They are part of the highest part of the rainforest canopy.

On the left is a Sulfur-crested Cockatoo, on the right are Crested terns. Both of these were taken at or near Fitzroy Island, a national marine park off shore from Cairnes, on the Great Barrier Reef.

The comb-crested jacana on the left is amazing to watch as it walks across the lily pads and feeds. If you look carefully, you can see its incredibly long thin toes that allow this. On the right is a photo of the mangrove in which the jacana lives. The photo was taken right at the end of the dry season, and you can easily see how much higher the water level gets. Tropical coastal wetlands like this are critically important habitat for many creatures- waterfowl, crocodiles, baby fish, etc. Many mangroves have been cut down and filled in, while others have been converted for aquaculture (especially shrimp farms). Other mangroves, like this one outside of Cooktown, have been preserved. Note that mangroves like this are breeding grounds for mosquitoes, and that sometimes Dengue fever is spread by the mosquitoes in this area.

I don't know what species these flowers are, but they surely were beautiful!

On the left are Austlian White Ibis; a common species, at the botanical gardens in Sydney. On the right is a platypus at the Sydney aquarium. While they can be found wild in the Sydney waterways, they are seldom seen- they like muddy water and are quite elusive.

On the left is the north shore of Sydney Harbor; on the right is Stoney Creek Falls, along a nice little tourist railroad outside of Cairns. Apparently, it can be quite dramatic during the rainy season, though this photo was taken at the end of the dry season.

On the left, termite mounds in a recently burned area, along the road to Cooktown. The burns are a vital part of keeping the ecosystem healthy. However, the fires we experienced in Sydney were a major problem, especially for the Koalas who can't get away from crown fires (which happens if fires have been suppressed, and they really get going). Those fires were mostly set by arsonists (10 had been arrested by the time I left). On the right are dancers at the Kuranda tribal center, demonstrating traditional firestarting techniques.

On the left, an opalized fossil. Opal is a silicate mineral which replaced the dinosaur's bone. On the right is a photo looking up through the flowering trees on Fitzroy island.

A native pine tree

A rainforest tree on Fitzroy Island

Australia is pretty impressive! I don't have any photos from my snorkel or dive on the Great Barrier reef, but it lives up to its reputation!