Spring in our northern climate may fairly be said to extend from the middle of March to the middle of June. At least, the vernal tide continues to rise until the latter date, and it is not till after the summer solstice that the shoots and twigs begin to harden and turn to wood, or the grass to lose any of its freshness and succulency.
It is this period that marks the return of the birds,–one or two of the more hardy or half-domesticated species, like the song sparrow and the bluebird, usually arriving in March, while the rarer and more brilliant wood-birds bring up the procession in June. But each stage of the advancing season gives prominence to the certain species, as to certain flowers. The dandelion tells me when to look for the swallow, the dogtooth violet when to expect the wood-thrush, and when I have found the wake-robin in bloom I know the season is fairly inaugurated. With me this flower is associated, not merely with the awakening of Robin, for he has been awake for some weeks, but with the universal awakening and rehabilitation of nature.
Yet the coming and going of the birds is more or less a mystery and a surprise. We go out in the morning, and no thrush or vireo is to be heard; we go out again, and every tree and grove is musical; yet again, and all is silent. Who saw them come? Who saw them depart?
This pert little winter wren, for instance, darting in and out the fence, diving under the rubbish here and coming up yards away,–how does he manage with those little circular wings to compass degrees and zones, and arrive always in the nick of time? Last August I saw him in the remotest wilds of the Adirondacks, impatient and inquisitive as usual; a few weeks later, on the Potomac, I was greeted by the same hardy little busybody. Does he travel by easy stages from bush to bush and from wood to wood? or has that compact little body force and courage to brave the night and the upper air, and so achieve leagues at one pull?
And yonder bluebird with the earth tinge on his breast and the sky tinge on his back,–did he come down out of the heaven on that bright March morning when he told us so softly and plaintively that, if we pleased, spring had come? Indeed, there is nothing in the return of the birds more curious and suggestive than in the first appearance, or rumors of the appearance, of this little blue-coat. The bird at first seems a mere wandering voice in the air: one hears its call or carol on some bright March morning, but is uncertain of its source or direction; it falls like a drop of rain when no cloud is visible; one looks and listens, but to no purpose. The weather changes, perhaps a cold snap with snow comes on, and it may be a week before I hear the not again, and this time or the next perchance see this bird sitting on a stake in the fence lifting his wing as he calls cheerily to his mate. Its notes now become daily more frequent; the birds multiply, and, flitting from point to point, call and warble more confidently and gleefully. Their boldness increases till one sees them hovering with a saucy, inquiring air about barns and out-buildings, peeping into dove-cotes and stable windows, inspecting knotholes and pump-trees, intent only on a place to nest. They wage war against robins and wrens, pick quarrels with swallows, and seem to deliberate for days over the policy of taking forcible possession of one of the mud-houses of the latter. But as the season advances they drift more into the background. Schemes of conquest which they at first seemed bent upon are abandoned, and the settle down very quietly in their old quarters in remote stumpy fields.