Island arks

Why investment in island conservation yields big dividends

Earlier this year three EDG researchers, Justine, Michael and Kate, attended the Island Arks II symposium in Canberra to discuss a wide variety of topics relating to conservation investment in Australia’s islands. Here are some notes on what was discussed. Justine and Kate are based at EDG’s University of Queensland’s node while Michael is based at the University of Melbourne.

Australia’s islands have biodiversity values that can be disproportionate to their size. Consider Barrow Island lying off north-west Western Australia. It’s home to 24 species that occur nowhere else on Earth (of which five are mammals).

But the conservation value of islands extends beyond their indigenous species. Consider the case of Bald Island, off the coast from Albany (southern Western Australia). Noisy scrub-birds (Atrichornis clamosus) had been presumed extinct until they were heard singing near a picnic area in Two Peoples Bay National Park (near Albany on the mainland). The rocky landscape had protected a small number of breeding pairs (perhaps fewer than 50) from wildfires, but the remaining population was under constant threat from fire and foxes. In the mid-1990s a few individuals were translocated to a series of nearby release sites,
including Bald Island. Not long after, the mainland populations were devastated by a series of wildfires which killed 92% of the mainland population. Bald Island has since also become home to the world’s second population of Gilbert’s potoroo (Potorous gilbertii), which previously existed as a single population restricted to an area of five square kilometres. It too was threatened by wildfire…




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