In order to put right what once was wrong,  the authorities of theParks and Wildlife Service of Tasmania decided to get rid of all the feral felines from Macquarie Island, part of Australia, in order to preserve the native wildlife, such as Royal penguins and other animals that use the island as a breeding ground.  Seemed like a good idea at the time…

What no one seemed to think was too important, though, was that although the cats were an invasive species, brought most likely on passing ships, they were currently filling a vital ecological niche:  keeping the non-native vegetation-munching rabbit population down. Seems the birds rely on that vegetation, and without the cats munching on the rabbits, the situation has become "hare"-raising.  (Ok, I admit it – ouch.)

Seriously, though. According to an article in the British Ecological Society’s Journal of Applied Ecology written by Dana Bergstrom of the Australian Antarctic Division and her colleagues, getting rid of the cats from Macquarie "caused environmental devastation" that will cost authorities 24 million Australian dollars ($16.2 million) to fix.

"Our study shows that between 2000 and 2007, there has been widespread ecosystem devastation and decades of conservation effort compromised," Bergstrom said in a statement.  It seems that not thinking through the possible problems with pulling one piece out of an ecological puzzle shows just how fragile an ecosystem is.

"The lessons for conservation agencies globally is that interventions should be comprehensive, and include risk assessments to explicitly consider and plan for indirect effects, or face substantial subsequent costs," Bergstrom said.

Macquarie was designated a World Heritage site in 1997 as the planet’s only island composed entirely of oceanic crust.  The island is located about halfway between Australia and the Antarctic continent and is known for its wind-swept landscape. Up to 3.5 million seabirds and 80,000 elephant seals come there each year to breed.

For decades, Australia has struggled to come up with a remedy for all the cats, rabbits, rats and mice that now inhabit the island. They threaten the native seabirds, some of them endangered species. While some good has come of the cat-reduction, such as grey petrels finally breeding successfully for the first time in almost 100 years, not getting rid of ALL the non-native predators at once has thrown the island off-balance once more.

However, the parks service has a new plan to finish the project, using technology and poisons that weren’t available before, and which will hopefully get rid of all the remaining rodents (and lagomorphs) without harming the other wildlife.

"Without this action, there will be serious long-term consequences for the majestic seabirds which nest on the island including the four threatened albatross species, and for the health of the island ecosystem as a whole," said Dean Ingwersen, Bird Australia’s threatened bird network coordinator.

"We believe that the process they are going to follow uses best practice for this type of work," Ingwersen said. "And that all possible ramifications have now been considered." 

(Sure, sure, right, right…)

Technorati Tags: Australia, Cats, Elephant Seals, Macquarie Island, Mice, Penguins, Rabbits, Rats, Wildlife Conservation