Teifi

Iolo explores the Teifi, known as the Queen of Welsh Rivers. His 76-mile journey begins at the river's mouth on Patch Beach where it flows out to Cardigan Bay. To his surprise, he discovers a mixed flock of Dunlin and ringed plovers in May, likely failed breeders beginning to gather before the summer. He also spots migrant Painted Lady butterflies that have travelled all the way from North Africa, and have stopped to feed on the nectar-rich flowers growing among the sea defences.

Heading upstream to the Teifi Marshes and the old slate quarries near Cilgerran, Iolo explores a landscape where nature has reclaimed industrial history. Amidst the slate spoil, he finds a slow worm hunting in the open, swollen-thighed beetles and observes a "two-for-one" nesting tree, where great spotted woodpeckers and great tits have both taken up residence in the same trunk. He also meets Rod Bowen, a local coracleman, to learn about a 2,000-year-old fishing tradition that is now under threat due to the dramatic decline of salmon and sea trout.

As the journey continues through the Teifi Gorge, Iolo stops at Cennarth Falls, a stunning spot that was once a reliable place to see migrating fish leap up the falls. He attributes declining fish to the elephant in the room: pollution from agricultural and urban sources. Iolo highlights the spread of invasive Himalayan Balsam before discovering a thriving kingfisher nest near Henllan. Watching a female return with a fish to her third brood of the season, he reflects on the resilience of the river's specialist residents.

A major highlight occurs at Maes y Crugiau, where Iolo enjoys a wonderful encounter watching an otter, as it hunts and eats an eel. The adventure reaches the vast ancient peatland of Cors Caron National Nature Reserve. On the boardwalks, Iolo finds the scarce whinchat, a bird that has largely disappeared from the lowlands but still maintains a stronghold here.

On a nearby wildlife-friendly farm, he witnesses the benefits of conservation-first agriculture, spotting golden-ringed dragonflies, ringlet butterflies, and a pair of kestrels successfully raising chicks in a nest box.

The journey concludes in the harsh, wintry environment of the Cambrian Mountains at Llyn Teifi, the remote source of this majestic river.