Iolo Williams looks back on the best Springwatch stories featuring changes to Welsh wildlife, and celebrates the conservationists giving back to nature.

Gillian Burke visits Gwaith Powdwr, an explosives factory transformed into an wildlife oasis. Iolo recounts stories of 2 arctic visitors – from Wally the Walrus who unexpectedly turned up in Tenby, and the dedicated effort to monitor the vulnerable Greenland white fronted geese who overwinter in Wales. Gillian visits a loyal birdwatcher who discusses changes the river Tiefi has revealed over decades, while researchers at Bangor university follow a surprising reptile introduced to Wales. Iolo recounts his early involvement in the pine marten re-introduction projects in Wales, and how it wouldn’t have been possible without an army of conservationists. Show less