Bird populations thrive as rat extermination plan succeeds

Ongoing surveillance on the island continues, including using rat-sniffing dogs every few months to ensure the unwanted pests are gone. The last rat sighted was in August last year.

Global programs to eradicate invasive species on islands have become a key tool against the extinction crisis.

The Database of Island Invasive Species Eradications tracked 2,000 programs between 1950 and 2019 and shows that programs on more than 800 islands had an 88 percent success rate.

But Lord Howe Island boasts the first rodent control program conducted on a permanently inhabited island.

It is just one of many wildlife programs run by the NSW Government. But it’s no small challenge. There are billions of wild animals in Australia and some of the worst offenders include rabbits, cane toads, cats and carp.

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Factors like successive natural disasters and climate change only increase wildlife populations. While invasive species thrive in warmer, cooler, wetter, or drier environments, some native species struggle to adapt to changing weather patterns.

Even as it recovers from pest infestations, Lord Howe Island suffers from a changing climate.

Island temperatures have increased by 0.8 degrees since 1950 and rainfall has decreased by 32 mm since 1970.

Ian Hutton, naturalist and curator of Lord Howe Island Museum, said in the 40 years he’s lived on the island he’s noticed the cloud layer thinning at the top of the mountains, what a delicate, endangered one moss is harmful.

Fishermen on the island are now catching more subtropical fish – an indication that the waters off the island are warming and parts of the lagoon were heavily bleached for the first time in 2019.

“We had major wildlife issues on the island, but we eliminated the threat. Climate change is a big issue that we need to tackle next,” he said.

What is often easier is managing other pressures on native species, such as B. better management of invasive species or habitat destruction, said conservation ecologist Dr. Justine Shaw from Queensland University of Technology.

“If you gave me $20 million to make an island resilient to climate change, maybe I’d throw it at irrigation schemes or species breeding programs — there’s a lot more uncertainty and complexity in climate change, how species are affected. But with clear management goals like eliminating invasive species, this is a tangible thing. We are confident that native animals’ chances of survival are likely,” she said.

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“Islands have unique biodiversity, they have unique species that aren’t found elsewhere.”

“We cannot eliminate every threat to species on islands, but studies show that invasive species are one of the biggest threats to native species, and eliminating them guarantees success.”