“It’s one of the few cases in which humans can permanently reverse some of the damage we’ve caused,” says researcher Melissa Houghton, after following a ten-year effort to recover Macquarie Island, an Australian territory that lies halfway between Australia and to Antarctica.
As the world looks primarily at endangered species, in this case the balance of the island was threatened by an excess of animals, with many invasive species introduced by humans since the 19th century.
Rats, cats and rabbits have multiplied out of control, and the consumption of these animals has shaken the ecosystem, decimated plants and bird populations, completely changing the local landscape, reports The Guardian newspaper.
Houghton arrived on the island as a dog trainer, and she and her Labrador Wags were responsible for locating many of the invasive species. The rabbit population alone reached a peak of 300,000 animals on the island, and without predators, these animals found a true feast in the open.feasting on local cabbages, a species of plant that can grow to the size of a person.
Sea elephants and penguins are frequent visitors to Macquarie Island, Australia. — Photo: Samuel Bloch/Getty Images
In 2014, the island was declared free of invasive species. The last wildcat was targeted in 2000, and its venom was used in 2010 to kill rats and mice, with rabbits also being targeted. But after accidental poisoning of native birds, calicivirus (a rabbit hemorrhagic disease) was released into the environment in February 2011.
The researcher, who has remained on the island since 2011, became a scientist and completed her doctorate as part of the research team monitoring the Macquarie resurgence. According to Houghton, there are still a few hundred rabbits on the island, but in places where you can’t find them, like cliffs.
Despite being drastic, the extermination of invasive animals showed results in the recovery of the terrain and local biodiversity. It’s a big chain.
Rabbits decimated the vegetation, and the slime grew in places where albatrosses might have made their nests before; smaller birds, which also used the island as a refuge for reproduction, were eaten by wild cats, or even, exposed by the lack of vegetation, became easy targets for predatory birds; the population of insects and invertebrates such as spiders grew again, once they were no longer food for mice. “Today there are cobwebs everywhere”, says the researcher.
The process of restructuring the Macquarie ecosystem cost £14m, and would have cost more had it not been for the support of existing research facilities, yet isolated islands are centers of biodiversity, each with its own variety. of flora and fauna.
“This management action, the eradication, has saved entire communities and species, many of which are found nowhere else in the world,” says researcher Justine Shaw of the Queensland University of Technology and supervisor of Houghton’s PhD.