Rare water voles are flourishing again in the Yorkshire Dales following a successful reintroduction programme by the National Trust.

More than one hundred water voles, which were the inspiration for Kenneth Grahame's The Wind in the Willows were released around Malham Tarn last August, the first time the little creatures had been seen in the area of 50 years.

Now nine months later, a survey has shown that the water voles have spread almost a mile away from the original release site, and are flourishing.

Roisin Black, National Trust ranger at Malham Tarn, said: “With a mild, wet winter, we were worried that the water levels around the tarn may rise too high and flood the burrows.

"But it turns out that the voles have spread out across one side of the tarn.”

A hundred new water voles will be released onto the fenland surrounding Malham Tarn over the course of this week.

The reintroduction is part of a plan by the National Trust to restore wildlife in the Yorkshire Dales. The National Trust aims to create 25,000 hectares of new ‘priority’ nature habitats by 2025.

"The water voles area already changing the look of the tarn-side streams. The banks used to be straight-sided, almost like canals," added Ms Black.