considerable numbers; the nests are generally placed
upon the summits of isolated rocks, or " stacks," as
they are locally called, but also by no means uncommonly
upon flat grassy islands in freshwater lakes, and
occasionally in open marsh- or moor-land. We found a
few nests of this Gull, from which the young had very
recently flown, on some isolated rocks of the Scilly
group in July. Although the young birds were strong
on wing and could take perfectly good care of themselves,
the parents swrooped fearlessly at us with fierce
barks as we rowed about their nesting-places, and in
one or two instances followed our boat closely to a
considerable distance.
The Great Black-back is accused of attacking sickly
sheep and lambs, and human beings who may have
the misfortune to be found in a drowning condition j
but I can speak from personal knowledge as to its
frequent minor delinquencies in the way of destroying
the young and eggs of Grouse, Peewits, and other
ground-breeding birds. This Gull is by no means
common, so far as my experience goes, in the Mediterranean
; but I have met with it occasionally on the
Guadalquivir within a short distance of Seville.