THE GLAUCOUS GULL. 
349 
breeds in Shetland, but often stays so very late as to give the 
impression tliat its not remaining throughout the year is deter- 
mined by only the barest turn of tlie scale. I have seen it in 
j\Iay, and have met with it even as late as June, tlie first birds 
returning for the winter usually appearing about the middle 
of October, when small flocks may be seen composed of botli 
old and young, the latter predominating in number. In winter 
by far the larger proportion are young birds, nearly all the old 
ones habitually disappearing shortly after their arrival. Like 
its miniature the Iceland Gull, the Glaucous Gull is very 
irregular in migration, but, on an average of years, both species 
have left Shetland for more northern regions by the middle or 
latter part of March. 
A very notable characteristic of the Glaucous Gull is its 
not infrequent tendency to congregate in flocks. One day in 
November 1864, in the face of a gale of wind, I saw a flock 
pass over, on the way southward, the components of which 
numbered as many as a hundred and forty, or thereabouts. 
Many at a time may often be seen upon the voes also, and 
occasionally the bird may be observed upon fresh water. It 
was indeed upon the loch of Cliff that I met with it at the 
late period of the season mentioned above. Mr Edmondston 
and I were upon the loch together, on the 17th of June 1861, 
and both of us saw two Glaucous Gulls in what apj)eared to 
be the second year’s plumage ; it was impossible that they could 
be less than a year old. They came so close to the boat that 
we could see their white quills, and the men in the boat, who 
of course know these birds well, were the first to notice them. 
We were greatly perplexed by the occurrence. 
This species may be recognised at a distance by the steady 
soaring, and by the wing being less bent at the carpal joint 
than it is in others of the genus. Nearer, it may readily be 
known by its conspicuous white or whitish quills. The general 
hue of the bird, at a distance, is a dull creamy white all over. 
In the water it sits more buoyantly than the Herring Gull, 
which, though smaller, is sometimes mistaken for it by un- 
