When I was eight, our family dog died and, for reasons best known to themselves, my parents decided to see how long it took us children to notice. It was three days. Sometimes an absence is overlooked, in the maelstrom of life, but only for so long. So it was that I sat on Winterton Beach, where the waves were choppy and a great mass of feeding seabirds gathered. Mediterranean gulls, a cormorant or two, some rowdy herring gulls. It was busy and active. I noted the common terns, diving into the water, and instinctively looked for the little tern, or “little pickies” to go by their Norfolk name. But there were none. Behind me, the fenced-off enclosure designed to protect them was empty. I felt that lurching sense of loss, especially as avian flu is wreaking devastating impacts on seabird colonies. I feared the worst – but there was no disaster. Little tern colonies often shift. According to the RSPB, the terns did attempt to nest here, but a couple of low-flying aircraft may have caused a “dread event”, where the birds abandon the site to find another. The species is so vulnerable. Their nests are mere scrapes on the beach, and their eggs, such speckled perfection, are nearly invisible on shingle and easily crushed underfoot on popular beaches. Little terns also face habitat loss, predation, food shortage and the risk of high spring tides washing nests away. After that, there’s the small matter of a perilous migration to west Africa. I head north along the coast to Eccles-on-Sea to find what I was missing. The colony is lively, noisy. I’m shocked afresh at how delicate little terns are. They flit over the sea with the grace of a swallow, then hover, briefly suspended, before slicing into the water, kingfisher-like. Many emerge with the glistening silver shock of a tiny fish, which they hurry back to a fluffy chick. All at once, the colony lifts into a raucous cloud. The RSPB warden scans the sky. Is this a kestrel attack? She is ready to sound the klaxon, but it’s a false alarm. Relative calm is restored. This is fragility, this is strength, this is life on the edge.