1810 Macquarie Island. First Europeans arrived.
Hunters slaughtered its seals for fur and blubber.
Then came the rats.
The rats ate the European’s food so they brought in the cats. Rabbits followed to compliment the diet. Rabbits flourished and by mid 20th century there were 150,000 of them. Then came the conservationists. They brought in a flea, (Spilopsllus cuniculi) that lives in the fur of the rabbit and carries the myxomatosis virus. Introduced in 1968 it cut the rabbit population by 90%. Vegetation started to recover. But there will still the cats. Without the rabbits to eat, the cats turned their claws on the remaining ground nesting birds. So, starting in 1985, the Australian government started shooting the cats. Some true ecologists thought this was a dumb move, and they were right. 15 years later the island was cat free, but with-out the cats the rats ran riot and ate the birds. The rabbits numbers began to increase again because they had never gone away completely. With-out the cats, their numbers revived dramatically. Their renewed grazing on the grasses began serious soil erosion and in 2006 a landslip buried alive an important penguin and albatross colony.
Back to square one so in 2007, the Australian government hatched a grand plan, costing $24 million Australian dollars, Everything had to go. They would eradicate rats, rabbits and the increasing numbers of mice by mass poisoning, using brodifacoum, with any survivors taken out by teams of hunting dogs.
Sometime in 2012 the dogs finally nailed what was thought to be the last 13 rabbits. Job done? Scientists back in Australia, sitting at their computer screens, running models on the island’s ecosystems, believed so. But don’t hold your breath. For the poisons (brodifacoum) had seeped into the soils and the vegetation and then began killing 1000s of birds, including kelp gulls, giant petrels, black ducks and skuas.
The story seems far from over. Nobody yet knows if the eradications have been achieved. And if rabbits start popping up again there maybe a call to bring the cats back.
Taken from Fred Pearce’s THE NEW WILD.
Posted this to highlight our reaction to “invasives” as usually seriously ill informed with consequences far beyond our immediate sight.
Injecting trees with poisons along our creek banks? Spraying drains with round-up?