Page:The Zoologist, 4th series, vol 6 (1902).djvu/444

378 very bold, and swooped quite close to my head while I was examining their nests.

(S. fluviatilis); (S. macrura).—Both these Terns were breeding on Walney Island and at Ravenglass. I found them most difficult to distinguish from each other, and of course when they were flying overhead in numbers, even although one thought to distinguish individual birds, it was quite impossible to tell which eggs belonged to them.

The Terns' nests on Walney Island were in close proximity to those of the Black-headed Gull, some being in the sand-hills, and some on the marsh, or "moss"; but there were a few small colonies in secluded spots of turf and shingle, quite separated from the large colonies. The Terns' nests at Ravenglass, except the Sandwich Terns, were on a stretch of dry grassy land at the foot of the sand-hills, and some distance from the Black-headed Gulls. I found that the nests which were made on the sand generally had a tolerably thick pad of coarse grass as a lining (there is a quantity of coarse grass growing on the sand-hills both on Walney Island and at Ravenglass, of which the dead blades seem to be found a useful article by the Terns and Gulls), the hollow thus lined measuring about 4 in. diameter by ½–¾ in. deep. Most of the nests made on the shingle had no lining at all, the nest-hollow being of about the same dimensions. The nests made on the short turf exhibited rather deeper hollows, with sometimes the lining of a few blades of the surrounding grass, but as often no lining at all.

I came upon two small outlying colonies, consisting of about half-a-dozen pairs of birds, in different parts of Walney Island, and spent some time watching them with my glasses until I satisfied myself that all the Terns breeding in these two spots were Arctic Terns. One of the small colonies was on a stretch of short turf close to the sea-front, and the other was on a small patch of shingle about one hundred yards inland. I examined four nests of those on the grass, and found them to contain two and three eggs, the nest-hollows being generally as already described. The eggs of one clutch which I took measured 1·6 in. by 1·15 in. In the colony on the patch of shingle I examined three nests, two of which contained three eggs, the other only two.