ARCTIC TERN. 
Sterna Arctica, Temm. 
L'Hirondelle de Mer arctique. 
Ir is to M. Temminck that we owe the knowledge of the present bird as constituting a different species from 
that of the Common Tern (Sterna Hirundo, Linn.), to which it bears so close a resemblance as almost to require 
actual comparative examination of the two species, to determine the characters which form the line of distinc- 
tion :—the accurate representation, however, which we have given of both species, with the minute indications 
pointed out in the letter-press, will, we trust, clear up every difficulty attached to these two species, so nearly 
allied, and so often confounded. We have ourselves had abundant proofs that the present bird is a constant 
inhabitant, in considerable numbers, of many parts of our coast, but more especially its northern portion, and 
the adjacent Islands the Orkneys and Shetland, where it is known to breed regularly; and it is not a little 
singular, according to the most credible information, that these Terns, although bearing so close an affinity to 
each other, do not associate together at the same breeding-places, but that each retains its peculiar locality 
although both breed in the immediate neighbourhood of each other. Thus one species will occupy an island, 
or a portion of it, to the entire exclusion of the other, and vice versé. M.Temminck informs us, that it is 
especially common in the Arctic circle, which he considers to be its true habitat, and where it occupies the 
place of the Sterna Hirundo of more southern latitudes. We have had opportunities of examining this species 
in all its stages, and we find that they strictly correspond with those of its allied congeners. The young 
offer also but little difference from those of our Common Tern. There is, however, one infallible rule by 
which not only the adult but the young in any stage may be at once discriminated, viz. by a comparison of 
the length of the beak and tarsus, characters on which the greatest reliance may always be placed. The 
Arctic Tern is altogether smaller and more slender, with a longer and more elegant tail, the beak wholly red 
and much less robust, as well as a quarter of an inch shorter, measuring from the gape to the tip; the tarsi 
are also proportionately smaller, measuring in length only seven lines ; to which may be added that its colour 
is much more uniform, nearly the whole of its body, both above and below, being covered by a blueish ash 
colour; the head and back of the neck black. 
It breeds among the shingles on the sea shore, the female laying two or three eggs very similar in colour 
and markings to those of the Common Tern, but smaller. 
We have figured a male in its summer plumage. 
