Welcome back to RSPB Arne at Poole Harbour, Dorset!

The hugely biodiverse wildlife haven and home of Autumnwatch is the base for another four days of wildlife observation, as Chris Packham (who can also be spotted on Insert Name Here tonight – BBC2, times vary), Michaela Strachan and Martin Hughes-Games return with more wildlife news and the latest on a few Autumnwatch favourites.

Today, Martin finds out why the harbour attracts wader birds, and Gillian Burke examines military pillboxes in Studland to learn about the habits of hibernating butterflies. Continues nightly until Thursday.