Iolo’s on a mission to see one of the most photogenic birds in the UK: the black-throated diver. There are live updates from Chris and Michaela in Norfolk – is there any sign of the elusive and rare turtle dove? Gillian enters the twilight zone to check out a British shark that can glow in the dark. And find out why water voles are choosing city life over country living.

The show’s own verdict is on its page.