Nuthatches are those blue-backed, white or rufous breasted little climbers who spend their lives defying the law of gravity. They need no supporting tail, and have only the usual number of eight toes, but they traverse the bark, up or down, head often pointing toward the ground, as if their feet were small vacuum cups. Their note is an odd nasal _nyeh!_ _nyeh!_ In winter some one species of bird usually predominates, most often, perhaps, it is the black-capped chickadee. They seem to fill every grove, and, if you take your stand in the woods, flock after flock will pass in succession. What good luck must have come to the chickadee race during the preceding summer? Was some one of their enemies stricken with a plague, or did they show more than usual care in the selecting of their nesting holes? Whatever it was, during such a year, it seems certain that scores more of chickadee babies manage to live to grow up than is usually the case. These little fluffs are, in their way, as remarkable acrobats as are the nuthatches, and it is a marvel how the very thin legs, with their tiny sliver of bone and thread of tendon, can hold the body of the bird in almost any position, while the vainly hidden clusters of insect eggs are pried into. Without ceasing a moment in their busy search for food, the fluffy feathered members of the flock call to each other, "_Chick-a-chick-a-dee-dee!_" but now and then the heart of some little fellow bubbles over, and he rests an instant, sending out a sweet, tender, high call, a "_Phoe-be!_" love note, which warms our ears in the frosty air and makes us feel a real affection for the brave little mites. Our song sparrow is, like the poor, always with us, at least near the coast, but we think none the less of him for that, and besides, that fact is true in only one sense. A ripple in a stream may be seen day after day, and yet the water forming it is never the same, it is continually flowing onward. This is usually the case with song sparrows and with most other birds which are present summer and winter. The individual sparrows which flit from bush to bush, or slip in and out of the brush piles in January, have doubtless come from some point north of us, while the song sparrows of our summer walks are now miles to the southward. Few birds remain the entire year in the locality in which they breed, although the southward movement may be a very limited one. When birds migrate so short a distance, they are liable to be affected in colour and size by the temperature and dampness of their respective areas; and so we find that in North America there are as many as twenty-two races of song sparrows, to each of which has been given a scientific name. When you wish to speak of our northeastern song sparrow in the latest scientific way, you must say _Melospiza cinerea melodia_, which tells us that it is a melodious song finch, ashy or brown in colour.