St Kilda's 'super-sized' field mice studied

Researchers have begun a study into a remote island archipelagos super-sized field mice, which can grow up to twice the size of their mainland cousins.

The islands of St Kilda, which lie 41 miles (66km) west of Benbecula in the Outer Hebrides, were abandoned by humans in 1930.

A team from the University of Edinburgh University wants to know why the mice came to be so big.

The mice weigh up to 50g and have pale-coloured hair on their underbellies.

Scientists will spend three years weighing and measuring the mice.

Tom Black, the PhD student is leading the study.

He said: "They are cute and a little bit different from mainland mice."

Mr Black added: "The theory is that because they're here with very little competition or predation, that allows them to get bigger and being bigger allows them to cope better with the extreme conditions out here, the cold and the weather."

Following the evacuation of the human population from St Kilda, field mice migrated from the hills to the abandoned homes and buildings.

Despite the field mice thriving, the change and lack of food resulted in extinction for the island's house mice, who took only two years to die out.