Country diary: Enter dolphins, stage left, ripping apart the limpid sea | Nigel Brown

Ynys Môn: Their energy was breathtaking, their display thrilling - though this was also a purposeful signal of their fitnessEventide, and calm waters were slowly departing the warm sands of a small Ynys Môn (Anglesey) bay. The dark igneous rocks that bound the bay had retained some midsummer heat, providing a comfortable vantage point to enjoy the sunset. In the shallows, a lone spectator watched the deep pink of the sea. My eyes followed hers and landed on two grey seals, their heads implanted in the iridescent waters. They watched, we watched, then they lazily slipped below, hardly a ripple raised.Enter the Risso's dolphins. A pod of four surfaced stage left, injecting the scene with breathtaking energy; their stout, torpedo-shaped, pale grey bodies surging forth, tall dark dorsal fins ripping the limpid sea apart. One after another, they breached clear of the water, their power and scale full blown, heightened by the intimacy of the bay. A thrilling display - but also, scientifically, a purposeful, non-verbal signal of their intrinsic fitness to potential mates and competitors. In midsummer, Risso's migrate from the pelagic deeps into the relatively shallow shelf waters of the Celtic Sea, perhaps providing more opportunities for social interactions. Continue reading...