Chris Packham and Michaela Strachan broadcast from RSPB Arne in Dorset, while Iolo Williams has spread his wings to the Dorset coast and Portland Bill bird observatory — a hotspot for seeing and recording returning avian migrants. Megan McCubbin continues her celebration of city wildlife in Glasgow and reveals some of the more unusual hangouts for the city's water voles, as well as discovering the origins of one of the city's newest and loudest residents. Vet and naturalist Sean McCormack reports on a worrying threat to the health of rivers — and it's one that all pet owners should consider.