138 MASKED GULL.
In the Orkneys two individuals of this species were taken at
Weatray; another in 1831. In Shetland one in 1831.
They have been known to breed hi Orkney.
These birds appear to be easily kept in confinement.
I n their flight they exhibit the 'esprit de corps' of the rest of the
family, and wing their way with characteristic case and grace.
The eggs are described as of a greyish green colour with dark spots.
Male; weight, eight ounces and a quarter; length, one foot two to
one foot three inches; bill, brownish red. The dark colour, that is
to say, the blackish red brown on the head, the lower part the
darkest, is in front only, somewhat in the way of a mask, and hence
the name of the bird. In winter the dark colour is lost, all but a
few dusky grey lines and a small dusky black patch under, and another
behind the eye. Crown, dark-coloured in front, the hind pari white,
as is the neck on the back, and the nape. Chin, blackish brown;
throat, blackish brown, mixing with the white of the breast; back,
pale bluish grey. The wings expand to the width of two feet eleven
inches or three feet; greater and lesser wing coverts, bluish grey; the
first primary is white tipped with black, a black line on the middle
of the outer web, and a greyish black border along the margin of
the inner web, being broadest at the base, the second and third without
the black line on the outer web; the fourth and fifth have a greater
portion of greyish black on the inner web, and all of them except the
first, with their extreme tips white, the shafts white adjoining the
white colour. Tertiaries, pale bluish grey, passing into white on the
tips; greater and lesser under wing coverts, greyish white. Tail,"white;
under tail coverts, white. Legs and toes, reddish brown.