676 LESSER BLACK-BACKED GULL. 
throughout the year, the breeding- a are chiefly on the coast, 
though some are inland. 
This Gull has not yet been obtained in Greenland or Iceland, but 
it is numerous during summer in the Feeroes, as well as along the 
coast of Norway, whence it migrates southward, on the approach of 
winter, as it does from the shores of the Baltic. Small colonies 
exist on some of the Channel Islands and along the western sea- 
board of France, as well as off Morocco and in the Mediterranean ; 
while in winter the bird visits the Canaries, and West Africa down 
to Bonny. Eastward it is found in Egypt, Nubia, the Red Sea 
(where it is said to be resident), and on the Persian Gulf. North- 
ward, it seems to be very rare in the Caspian, and hardly known to 
the east of the line of the Dwina, though Mr. Popham obtained 
an immature example at Golchika on the Yenesei. Its represen- 
tative, however, from the Dwina eastward as far as the Yenesei 
valley, is the Siberian River-Gull, Z. affinis, a species which has been 
obtained (once) in South Greenland, and perhaps on Heligoland, 
while it visits Western Asia and Equatorial Africa in winter. This 
has a paler mantle than Z. fuscus, and is distinctly larger. 
The nest of the Lesser Black-backed Gull is made of grass, bits 
of sea-weed &c., and the eggs, sometimes laid by the first week in 
May, and 3 in number, are smaller on average than those of 
the Herring-Gull and exhibit greater variation, with a tendency to 
bluish-green in their ground-colour: measurements 2°8 by 1°9 in. 
The food consists chiefly of fish and small crabs, the indigestible 
portions of which are thrown up in large pellets, and Mr. T. E. Buckley 
has found similar castings composed of the husks of grain; the 
bird is, however, omnivorous, and is very injurious to the eggs and 
young of moorland-game and water-fowl. 
The adult in summer is white, except on the mantle, which varies 
from slate-grey to black ; the three outer primaries are of a dusky 
black which becomes paler towards the edges of the inner webs, 
though there is no grey ‘wedge’; a sub-apical white mirror exists on 
the rst and—in mature birds—on the 2nd quill ; the legs and feet are 
yellow, and the relative shortness of the latter is characteristic. In 
winter the head and neck are streaked with dusky-brown. Length 
ofa male 22 in., wing 16-16'5, tarsus 2°6, middle toe with claw 2°25 
in.; the female is usually smaller. The young bird is similar to the 
immature Herring-Gull, but the upper parts are darker, and the 
primaries are nearly uniform black ; the lower part of the tail is crossed 
by a black band, which gradually breaks up into mottlings and dis- 
appears with increasing age ; the legs and feet are at first light brown. 
