The east coast of North America does not run north to south, as you might expect, but in a south-westerly direction. This means that for birds migrating from their breeding grounds in the Canadian Arctic to spend the winter in South America, the quickest and most direct route lies over the sea: specifically, the western part of the north Atlantic Ocean.
If the weather conditions are fine, then these birds will navigate their way successfully. But the autumn migration coincides with the peak season for tropical storms and hurricanes, which often progress along the eastern seaboard of the US, then sweep across the Atlantic towards Europe.
When these occur in late September, this coincides with the peak numbers of waders – or as Americans call them, shorebirds – heading south. Birders on the European side of the Atlantic then look out for a whole range of these charismatic birds, especially at west-coast hotspots such as the counties of Kerry and Cork in Ireland, and Cornwall and the Isles of Scilly in Britain.
The most frequent species is the pectoral sandpiper, a common and familiar bird in the US. But another regular visitor, the buff-breasted sandpiper, is something of a rarity there. It breeds only in the high Arctic, so is rarely seen on its journey south – even though it regularly occurs in small numbers in Britain.
