November Twenty-eighth
On returning to the nest and discovering that a cowbird has laid an egg in it, some species of birds will roll the egg out. But the phœbe, red-eyed vireo, chipping sparrow, and yellow warbler will sometimes cover the eggs with nesting material and build up the sides of the nest, thus burying its own and the cowbird's egg. Another set of eggs is then laid and the bird begins to sit, but the buried eggs are too deep to be affected by the warmth of the parent's body, so the "lazy-bird's" purpose is defeated.
November Twenty-ninth
In the abandoned birds' nests that are placed near the ground in shrubs and small trees close to hazel-nut bushes and bitter-sweet vines, you will often find a handful of hazel-nuts or bitter-sweet berries. They were put there by the white-footed mice and the meadow mice who visit these storehouses regularly. Very often a white-footed mouse will cover a bird's nest with fine dried grass and inner bark, and make a nest for itself.
November Thirtieth
Between now and the first of March you may expect to see large flocks of red-polls feeding on seeds among the weeds and low bushes, and cross-bills in the pine and spruce trees shelling seeds from the cones.
Reproduced by the courtesy of the Field Columbian Museum.
A FOUR-STORIED WARBLER'S NEST. EACH STORY REPRESENTS AN ATTEMPT BY THE WARBLER TO AVOID BECOMING FOSTER PARENT OF A YOUNG COWBIRD.