SIGHTINGS of water voles, the UK’s fastest declining mammal, on Britain's canals have doubled.

The water vole, immortalised as ‘Ratty’ in The Wind in the Willows, joins nearly 300 different species of birds, amphibians, reptiles, insects and other mammals that have been spotted making their homes on Britain’s inland waterways this year.

Rare butterflies, otters, an alligator snapping turtle were among the less common of the 42,500 sightings recorded – even a porpoise was spotted by a passing boater earlier this year along the River Ouse near Selby.

It was a good year for sightings of the survey’s focus species, the bumblebee, as a warm start to summer meant that a healthy number were spotted taking advantage of waterside wild flowers.

Jonathan Hart-Woods, environment manager for British Waterways, said: “The appearance of such a wide range of wildlife is generally accepted as a key indicator of a healthy ecosystem.

“Maintaining suitable habitats is a big part of our work and each year we’re involved in different conservation projects to preserve and encourage wildlife to the waterways. Barn owl nesting boxes have also been introduced in order to increase bird populations.”