CHAPTER XXXI.
GULLS AND TERNS AT HOME [Illustration: Herring Gull.] Gull Island was only a great sand heap, anchored by rocks and covered with coarse grass; but the children had hardly taken a few steps along the beach when they began to exclaim at the number of strange birds.
Some were flying, others walking about on the sand, where there were many tufts of grass and mats of seaweeds that looked as if they had been used for nests.

Dodo nearly stepped upon a couple of greenish, dark-spotted eggs, that were nearly as large as a Hen's.

"Are the Gulls still nesting, Uncle Roy?
And what are those dark streaky birds over there ?" "These are left-over eggs that did not hatch, for nesting is over in July at latest, and the dark birds are young Gulls in their first plumage.

They are brownish gray, streaked and spotted as you see, while the old birds are snow-white with pearl-gray backs, and black and white wing-markings in the summer, though their winter dress is not quite so pure, being streaked with gray on the neck." "Then the very dark Gulls I have seen off our beach in winter are the young ones ?" said Rap; "I never knew that before.

I don't believe many people remember how birds change their colors, and a great many never heard about it at all, I guess." "Gulls walk very nicely," said Nat.