Bats are thriving on the UK's canals and rivers, with a 9% increase in numbers spotted in this year's annual wildlife survey, British Waterways said on Friday.

And the prospect of another cold winter will be good for bats, ecologists at British Waterways said, as it will help them to hibernate properly.

The annual survey run by the organisation, which manages canals, rivers and docks around Britain, recorded a rise in bat numbers this year compared with last year, putting them among the top 10 creatures recorded on waterways by members of the public.

The most commonly seen species was the mallard duck, followed by the Canada goose, occupying the same top two spots as last year. Butterflies came in third place, a rise from 10th last year, the survey revealed.

Experts at British Waterways said one of the biggest issues facing UK wildlife was the fragmentation of habitat, and rivers and canals provide species such as bats with safe, food-rich routes that link patches of woodland and meadows.

Dr Mark Robinson, British Waterways' national ecologist, said: "Canals and rivers are a bit like supermarket shopping aisles for bats, and having spent the autumn using these corridors to travel and feed, bats should by now have stored up as much fat as they can, ready for the cold.

"Hibernating then allows them to save all this energy for the long winter months when there is little food about.

"Longer autumns and warm winters trick bats into thinking there are insects around and they use up valuable energy looking for them, thus risking potential starvation."

But while another cold winter will be good for bats and other hibernating species such as hedgehogs, species such as kingfishers may struggle due to the difficulty in finding food in frozen conditions.

Robinson said: "Bats are a traditional star of Halloween and it's no coincidence that we think of them hiding out in cold, dark and undisturbed places.

"Bats need a consistently cold place of -5C to hibernate. This allows them to slow their metabolism right down, meaning these astonishing creatures take much less frequent breaths and survive on only a few heartbeats a minute."