Island's 'Perfect' Conservation Backfires Catastrophically

Macquarie Island, a World Heritage site, serves as a stark example of conservation gone awry. An effort to remove invasive feral cats, which preyed on native seabirds, inadvertently triggered a devastating ecological cascade. The absence of cats allowed the rabbit population, previously controlled by them, to surge dramatically.

Introduced decades earlier, rabbits had already damaged the island's unique flora. After the cats were eradicated by 2000, the rabbit numbers rebounded to approximately 130,000 by 2006. This unchecked grazing led to the destruction of the island's vegetation, replacing complex plant life with short lawns or bare ground.

The scale of the devastation was significant, with over 36% of the island visibly altered and 17.5% experiencing moderate to severe damage. Rabbits also began destroying petrel burrows, further threatening the native seabirds the initial program aimed to protect.

Recognizing the severity of the crisis, Australian governments invested AU$24 million in an emergency integrated program to eradicate rabbits, rats, and mice simultaneously. This case highlights the complex interconnectedness of ecosystems and the risks of invasive species removal without a comprehensive understanding of ecological responses.