This page is an extract of a script that is part of the video series
"The Living Landscape-an Australian Ecosystems Series".
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LORD HOWE ISLAND wooden
Because islands are isolated places, conditions may be significantly different from those on the mainland. Sometimes, species will develop that take advantage of these conditions. An example is the Lord Howe island wooden, a unique flightless species.

When Lord Howe Island was first discovered in 1788, there were no signs that humans had ever lived there. The only mammals were bats, and there were few reptiles. But there was a profusion of plant and bird life, most of which occurred nowhere else in the world. The Lord Howe Island wooden was one of these species. There were no predators on the island, so a flightless species of bird was able to evolve.

But many species of birds on Lord Howe Island have disappeared, and the wooden was almost one of them. Sailors from early whaling ships introduced mammals to the island: goats, rats, pigs and cats. The goats ate the vegetation, the rats ate eggs, the cats ate birds. The flightless and vulnerable wooden almost became extinct. But a program of captive breeding and re-release has now ensured their survival.

It can be seen that the very isolation of islands, which allows rare species to evolve, also means that extinction of species is a constant danger.

Plants reach islands in different ways. Some grow from seeds that float ashore. Other seeds arrive by bird - either in the birds faeces, or attached to the birds themselves.

THE PISONIA TREE'S STICKY SEEDS
Some plants, such as the pisonia trees that grow on the islands of Queensland's Great Barrier Reef, have seeds covered with a sticky substance. The seeds are spread by the black noddies that nest in the trees during the breeding season.

BLACK NOODIES NESTING IN PISONIA TREES
A special relationship exists between these birds and the pisonias: the trees provide secure nesting places, and the birds supply the trees with the enriched soil they need to grow, from their faeces. When the pisonia fruits are ripe, they stick to the noddies' feet and feathers, and the seeds are distributed as the birds depart.

Sometimes, the seeds stick only too well - which explains why the pisonia's also known as the bird-catching tree.

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