Sticking in there

The ecological significance of the Lord Howe Island Group, an imposing and beautiful cluster of volcanic islands about 500 kilometres off the coast of New South Wales, is undisputed. First discovered by Europeans in the early nineteenth century, the islands have been actively studied by naturalists ever since and there is therefore a great deal of historical information about the flora and fauna. This is just as well as the same ships that brought people to the islands also brought rats, which have, predictably, led to the extinction of a number of species. A World Heritage-listed site since 1982, Lord Howe Island boasts an impressive 150 endemic plant species, as well as several endemic algae, fish, echinoderms, and birds. The island group is ecologically important for its diverse habitats, the fact that its ecosystems are largely intact, and because it is home to a number of threatened species. It is the site of the southernmost coral reef and spans a unique transition from coral to algal reef, therefore supporting an unusual juxtaposition of tropical and temperate marine species. The kentia palm, popular the world over as an indoor plant and well known as a favoured decoration in Victorian ballrooms, grows wild on Lord Howe Island. Most recently the island has yielded the first persuasive evidence of sympatric speciation — the divergence of the kentia (Howea forsteriana) and curly (Howea belmoreana) palms. Less popular with the general public, but of equal ecological importance, are the insects and the island group is home to a number of interesting species. Among them is a soil-burrowing cockroach on the brink of extinction; and the rarest insect in the world (perhaps the rarest invertebrate), the Lord Howe Island phasmid. The former is a large, flightless cockroach that lives in burrows that extend about a metre under ground. They bear about 30 live young at a time and, because native cockroach species tend to live in isolation, they are particularly suited to population and evolution studies. They are extinct on Lord Howe Island, but a small population still exists on an island in the island’s lagoon, and their cause is being championed by Associate Professor Harley Rose of the University of Sydney. The latter is a magnificent, flightless stick insect measuring up to 15 centimetres long and known to locals as the land lobster or sometimes tree lobster. They were last seen on Lord Howe Island in the 1920s, quite soon after the 1918 shipwreck credited with their extinction. These massive insects are known to be nocturnal and to feed on and nest in trees. It was therefore extremely surprising