A remote island in the Indian Ocean is about to become the stage for a radical rodent control operation. We are talking about Marion Island, located about 2,000 kilometers off the coast of South Africa, where the Mouse-Free Marion Project – an environmental conservation program supported by the South African Ministry of the Environment – plans to (literally) bombard the island with rodenticide, in a last-ditch attempt to save the local albatross colonies from the ravenous attentions of a community of mice that has now grown out of control.
Marion Island has been a pristine paradise for millennia, home to a rich variety of seabirds (and more), many of which are now threatened with extinction. Among them is the iconic wandering albatross (Diomedea exulans), classified as vulnerable by the International Union for Conservation of Nature (IUCN), and holds the record for the largest wingspan of any bird. It is estimated that about a quarter of the world’s population of wandering albatrosses resides on Marion Island, and their disappearance from the island would therefore seriously jeopardize the survival of the entire species.
This rich and isolated ecosystem is now in danger because of rats: rodents unintentionally introduced by man in the nineteenth century, which have found the island a perfect environment to reproduce and thrive, and which, following climate change in recent decades, have begun to increase in number, devastating the populations of birds that nest on Marion Island.
According to environmentalists from the Mouse-Free Marion Project, the mice have now begun to attack the adult specimens, using their nests as dens and seriously endangering the survival of all the avian species on the island, which, having had no natural enemies for centuries, have no way of defending themselves from these new attacks.
In the past, an attempt was made to control the rat population by introducing cats to Marion Island. But the experiment went awry, and the birds soon found themselves dealing with about 2,000 feral cats, forcing authorities to remove the feline colony from the island entirely. Now, with time running out, a new, more extreme strategy has been devised. The plan involves using helicopters to drop poisoned baits all over the island, so that every single rat on Marion Island has a chance to eat at least one.
The baits and poison have been specially designed to ensure that they are palatable to local rodents, that they will persist in the environment for a long time, which will ensure that the entire mouse population is reached, and that their toxicity is precisely calibrated so that they are lethal to the rodents, but do not damage the environment or pose a risk to the survival of the birds. After an initial “bombing”, a pause is planned, and then a second application of the poisoned baits, to ensure that every last mouse is eradicated from the island.
The program plans to begin operations in the winter of 2027. In the meantime, the Mouse-Free Marion Project has launched a fundraiser to finance the venture, which should cost a whopping $29 million to complete. For those who want to participate, the initiative’s website contains all the necessary information.