EVERY WEEK IN 2017 WE WILL HAVE NEW SUGGESTIONS FOR A DIFFERENT GROUP OF BIRDS TO LOOK FOR TO HELP DEVELOP YOUR #MY200BIRDYEAR LIST.
This week, it is sea terns
Terns are the fork-tailed, smaller, more delicate relatives of the gulls. Our terns fit into two broad categories: the sea terns and the marsh terns. The latter are three small species which are passage birds in the UK. The sea terns include five species which breed in this country, some commonly, and one as a very scarce breeder. All are pale grey with black caps. Common and Arctic terns can be tricky to tell apart, but Little and Sandwich Terns are pretty distinctive. The rare Roseate Tern is like an exaggeration of an Arctic Tern.
The standard, familiar ‘sea swallow’, the Common Tern is a familiar sight not only at the coast but also at inland sites, such as gravel pits and lakes with relatively un-vegetated islands (and readily adapting to ‘tern rafts’). They are graceful, elegant birds with a distinctive flicky wing action. In many ways Common and Arctic Terns are very similar. Note the following features (all Common tern features): longer more orange-red bill with a black tip; at rest wings are about the same length as tail; flight feathers have darker grey smudges in a wedge shape; flight style languid and flicky, with wings seemingly set further back than on Arctic Tern; red legs are longer than Arctic’s.
A very similar bird to the Common Tern, the Arctic tern is largely a coastal breeder, mainly of northern coasts (around Scotland, Ireland and northern Wales). They do pass through inland areas on passage, especially in spring (late April to early May), but don’t stay to breed like OCmmon terns. Form Comon Tern not the following Arctic features: shorter blood-red bill, without black tip; at rest, very long tail streamers extend beyond wing tips; flight feathers look very clean and translucent, never with darker wedges; flight style slightly stiffer than Common, with wings seemingly set further forward (partly because of very long tail); Legs are very short.
The Sandwich Tern is our largest breeding tern, considerably larger than Common and Arctic Terns, and with a different structure, looking front heavy, with a larger head and short tail. In breeding plumage, the back of the crown looks shaggy or spikey. The bill is black with a yellow tip. Sandwich Terns are coastal breeders, nesting on suitable beaches especially on the east and southern coasts of England (though at other places as well). They have distinctive coarse, creaking, hoarse ‘kirrick’ calls .
Little Terns are truly tiny terns a fraction of the size of their larger cousins. With relatively large heads and short tails, they are like mini versions of a Sandwich Tern, but a speeded up version! Unlike the larger terns, the bill is yellow with a black tip and the forehead white in breeding plumage. Little Terns have a similar coastal breeding distribution to Sandwich Terns, but there are fewer than 2,000 pairs in the country.
Our rarest breeding tern (with fewer than 100 UK pairs, mainly in Northern Ireland and Northumberland), the Roseate tern is like an extra pale plumaged mix of Common and Arctic terns. Its tail is even longer than Arctic’s, but its legs are quite long and the bill largely black with a red base.
All photos from Alamy