Mass extermination planned for ravenous rodents on South African island

World News

By Deirdre Bardolf

Conservationists are hoping invasive mice threatening the ecology of a South African island will take the bait.

A mass extermination is in the works to wipe out the ravenous rodents, which have been breeding nonstop and preying on adult seabirds and their chicks on Marion Island, one of the two Prince Edward Islands about 1,200 miles southeast of Cape Town set aside as a nature reserve.

Mice were accidentally brought to the uninhabited territory in the Southern Ocean near Antarctica 200 years ago, likely on the ships of seal hunters who landed there.

As global temperatures have risen, the nature reserve has become more hospitable to the ruinous critters. Fewer get killed off in the winter and in the past few decades, they have grown increasingly destructive, according to Dr. Anton Wolfaardt, head of the Mouse-Free Marion project.

Up to 550 tons of rodenticide bait will be dropped on Marion Island, Woldaardt said, but $25 million needs to be raised first before the plan, slated for 2027, can go forward.

The region is home to important populations of about 30 bird species, including four types of penguins and the endangered wandering albatross, which lacks the defense skills to fend off the attacks. The area was an undisturbed habitat for them until the mighty mice took over.

A single mouse on Marion Island will feed on a bird several times its size — a phenomenon seen in only a handful of the world’s islands.

Photos taken by conservationists showed a tiny mouse gnawing away on the head of a bleeding wandering albatross chick.

Mice will nibble on the heads of the chicks all night, leaving them exhausted and trying to recover from their injuries, according to National Geographic. Researchers first started noticing scalped birds around 2009.

If successful, the project will be the largest extermination of its kind — but if even one pregnant female survives, the cat and mouse game could continue. The vermin start reproducing at just 60 days old and females can birth up to 40 babies a year.

The effort is seen as critical to the territory and surrounding southern Indian Ocean. If nothing is done, conservationists say 19 species of seabirds will be eliminated from the island in the next 100 years.

The project is a partnership between BirdLife South Africa and the national Department of Forestry, Fisheries and the Environment.

With Post wires