360 
LARID^. 
are also fond of running along with the wings half spread, 
whether the nest is commenced or not. One who would visit 
them in their favourite haunts should go to the northern part of 
Unst, where they breed in great numbers, though decreasingly 
so every year. My impression is, that they breed in only four 
of the Shetland Islands besides Unst, viz.. Yell, Fetlar, Noss, 
and Foula. Soon after arrival they assemble at the breeding 
grounds, which are as often as possible in elevated situations, 
the grassy tops of high cliffs projecting into the sea being pre- 
ferred. The nests are upon the ground, and in most cases 
are rather carelessly constructed, the materials used being 
moss, short grass, and bits of heather. The eggs are laid dur- 
ing the latter part of May, and, as was said in the case of the 
Great Skua, are apt to be very much darker in the early part 
of the season, The most usual kind is a dark olive green, 
slightly blotched and spotted with dark browm, measuring two 
inches four lines by one inch eight lines. I have known an 
egg three lines longer, but of the same breadth ; — the shorter 
diameter of an egg being at all times and for all species, so far 
as my observations have gone, less liable to variation than the 
longer. From a number of eggs of this species brought me on 
the 6th of June, I selected the following varieties, viz. : — Very 
pale olive green, without any marks ; olive brown, so dark 
that the usual brown marks could with difficulty be seen ; 
greenish stone colour, marked wdth brown and grey ; clear 
dark olive green, marked with olive brown of several shades ; 
greenish grey, marked with dark brown and brownish grey. 
Thus the diversity in the colouring must not be regarded as 
wholly due to the degree of advancement of the season, all 
these being quite fresh when brought to me. It may be 
remarked, by the way, that Shooies’ eggs very soon spoil if not 
blown. I have repeatedly noticed this. 
The young when newly hatched are covered with a brownish 
coloured down. One was brought to me in this condition on 
the 17th of July, just barely able to run a little, and I kept it 
until the 6th of September, when it died. The Arctic Skua is 
