Nidderdale snakes are being studied to help assess populations nationally.

Adders in the Yorkshire Dales are to be studied as part of a national project examining how healthy their populations are across England.

The Nidderdale National Landscape (NNL), a designated Area of Outstanding Natural Beauty, is playing a leading role in the Natural England recovery project.

Scientists said the snakes were in decline nationally, with Nidderdale selected for the DNA analysis study due to its “well-monitored populations and extensive semi-natural habitats”.