Arguably, one of our most attractive ‘seabirds’ the delightful, buoyant Black Tern, unlike its cousins, is not really a bird of the sea at all.
Along with the rare Whiskered and White-winged Black Terns, it is what is known as a ‘marsh tern’. These three small tern species breed in shallow freshwater or marshy habitats (hence the name) and feed by dipping and picking or hawking for insects.
Though the Black Tern has bred in the UK, it is essentially a passage bird, passing the coast and inland water bodies on the way to the breeding grounds on the continent.
They pass in late April and May when they are generally looking much more handsome than they do on their autumn return. In spring, they are silky black of body and silky grey of wing (sometimes with some retained winter white specks until later in the season).
So, they are easily picked out by plumage, and also by size, as they are much smaller than for instance Common Terns, closer to the tiny Little Tern.
Individuals and groups (of varying size) stop by at inland lakes, gravel pits and reservoirs to dip and pick insects from the surface, before moving on.
They are not common birds in the UK, numbering in hundreds on passage in total, rather than thousands. But they can turn up anywhere and can make your May day.