IS Anglesey reserve the tern capital of Britain?

Elegant Tern (Mark Sutton)

All terns are, in my book, elegant: sleek seabirds that wander the oceans. They connect North Wales, which is home to four species of tern at five busy colonies, with the western and south coasts of Africa, and even the edge of the Antarctic. But by its name, one tern is more elegant than others – and its appearance at Cemlyn, on Anglesey, on Sunday and Monday provided a dose of birding excitement between the rush of spring and autumn migration.

The Elegant Tern, found at Cemlyn on Sunday morning, originates on the Pacific coast. Up to 95% of the world population breeds on a single island, Isla Rasa, in the Mexican state of Baja California. A few hundred pairs also nest in San Diego Bay in the USA, and in winter they feed along the coast as far south as Chile.

Elegant Tern is an incredibly rare visitor to Britain, although one has already visited North Wales, at Black Rock Sands near Criccieth in 2002. Sporadic appearances in Britain and Ireland are believed to relate to a small number of birds that have summered in western Europe over the last 20 years. One or two pairs have bred at Albufera de Valencia, a coastal lagoon in eastern Spain, in the last decade and Elegant Terns have also been seen on Noirmoutier Island, at the mouth of the River Loire. A pair is currently feeding two chicks there, the first breeding record for France. Individuals have previously bred with Sandwich Terns in France and Spain, producing hybrid young. It’s not clear what led to this massive expansion in its global range, which began in the 1970s, but the trend has been attributed to greater frequency of El Niño, the warming of currents in the Pacific Ocean.

Cemlyn, which is celebrating its 50th anniversary as a North Wales Wildlife Trust reserve this year, is no stranger to unusual terns. Staff and volunteers warden the important breeding colony of Sandwich, Common and Arctic Terns, joined in some years by Roseate Terns. That means there are extra pairs of eyes to pick out surprising visitors, and the reserve has hosted Caspian Tern (1980 and 1988), Bridled Tern (1988), Sooty Tern (2005) and White-winged Black Tern (2014). With occasional Little and Black Terns too, has any other site in Britain hosted 11 different tern species?

Elsewhere in North Wales, unusual visitors include Rose-coloured Starlings at bird-feeders in gardens in Moelfre and Rhos-on-Sea, four Avocets and three Great White Egrets at RSPB Conwy and a Cattle Egret at RSPB Cors Ddyga. One of the eagle owl species, almost certainly an escaped captive bird, has been hunting around Amlwch harbour in recent evenings, perhaps the same bird that was seen in Pentraeth forest during the winter.