But many species of birds on Lord Howe Island have disappeared, and the wooden was almost one of them. 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. 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. When the pisonia fruits are ripe, they stick to the noddies' feet and feathers, and the seeds are distributed as the birds depart.