Mice are ruining island ecosystem

A plague of house mice is wrecking the ecosystem of one of the world’s most beautiful islands, a study says.

They were introduced to the Farallon Islands, 30 miles off San Francisco, by 19th-century sailors.

But the population has soared to about 50,000 and they are eating their way through native insects, seabirds and plants. The US Fish and Wildlife Service now plans to eradicate them.

Prof Michael Polito, the lead study author, of Louisiana State University, said: “Native plants and many animals can’t leave the island to get away from the mice. These plants and wildlife never had to evolve defensive behaviours against rodents in the way mainland species have.”

Pete Warzybok, the co-author, said: “These findings make a stronger-thanever case for the eradication of the mice as a crucial step in restoring the Farallon Islands ecosystem.” The study is published in the journal Peerj.