This autumn Chris and Kate travelled to Weymouth to visit a large roost of wagtails who have taken up residence in a ferry terminal car park.
Wagtails have distinctive black and white plumage and long tails. Their characteristic habit of bobbing the tail up and down has given them their name but they also make a unique sound by snapping their beaks.
Two subspecies of wagtail have been recorded in the UK: the more common pied variety with a black rump, and the rarer and paler white wagtail.
Pied wagtails are year-round residents in southern areas of the UK but some breed in the uplands and migrate south in the winter, even crossing the channel. White wagtails tend to pass through the UK in the autumn on their migration to southern Europe and Africa.
Although they usually forage individually, wagtails tend to gather at dusk to roost together, most likely for warmth as well as safety. The largest known roost recorded was in a Kentish reedbed and had about 5000 individuals, and the longest recorded period of residency was 30years.
Recorded roosts of wagtails have been in car parks, sewerage plants, reservoirs and old buildings.
The enhanced version of the site requires JavaScript to be enabled on your browser. To find out how to turn on JavaScript, go to the WebWise JavaScript guide or visit the Autumnwatch group on Flickr.
To join the Autumnwatch group on Flickr, press the submit button and read our group rules before posting.
From red deer to spiders to fungi, share your pictures of autumn.
Red deer
UK's largest resident deer species.
Birds on the edge of Britain
Radio 4 team recording at a Manx bird sanctuary.
Your movies
Whether an unusual wild visitor to your garden or some truly extraordinary animal behaviour, if you've filmed it, we'd love to see it.