#two mice

New Post has been published on http://www.newsnish.com/technology/science/two-mice-conquered-an-island/

Two mice conquered an island

Mice are renowned breeders. Leave two alone in a cage, so the joke goes, and expect to return to a dozen.

But the ability of mice to procreate has been revealed by a novel and shocking experiment. Invasive species are a huge problem for conservation. Alien species can predate on local species, threatening their survival, or they can change the local ecology. These problems are exaggerated on islands. In extreme cases, invasive species, usually transported by human activity, have driven native species to extinction.

For example, in the last 500 years, species such as rats, cats and mice have driven over 70 bird species to extinction, according to BirdLife International, the global conservation alliance. These problems continue today. In January wildlife biologists embarked on the next phase of what has been described as history’s largest rat-eradication program, on the remote island of South Georgia in the far south Atlantic. There, introduced rats have wiped out almost 90% of the seabirds, including wandering albatrosses and the diminutive Wilson’s storm petrel. The rats raid the birds’ nests for eggs and chicks.

But scientists have only been able to make educated guesses about these alien rodent invasions, reconstructing what they think must have happened from the available evidence. Now a team of researchers based in New Zealand have taken a different approach. Helen Nathan of the University of Auckland and colleagues intentionally introduced two mice (Mus musculus) onto a small island to see what would happen.

The researchers chose Saddle Island (Te Haupa), which has an area of six hectares. Located 950 metres offshore from mainland New Zealand, the outer island is covered by sandy beaches, dunes and steep cliffs. The interior is forest and there is no permanent source of fresh water.