( Originally Published 1910 )
THE period during which the majority of our birds return to us after the winter's absence is a time of peculiar advantage to the bird lover. It seems good to welcome back our friends, and these pioneers give an especial thrill of pleasure. This feeling is the more enhanced because of the scarcity of birds during the winter. There is, too, a certain delight in being afield at the time when Nature is awakening, when the sun beams warm again, causing the spring aroma to arise from the fruitful earth and the early flowers modestly to open to our view. It might seem as though there were beauty enough to call people forth from their shells of sedentary employment even apart from the birds. 'Yet these will furnish an immediate motive without which many a ramble would be lost or postponed.
It is a fascinating no less than a healthful pursuit to " keep tab " on the arrival of the spring birds. As though realizing that it is important to make a good impression, they come arrayed in their very best garments, all of these new, and some a wedding outfit.
Everything considered, the birds are remarkably regular in their return each spring according to calendar. Each species has a certain normal time of arrival, and in most years the dates will not vary much. It seems wonderful that, with only instinct to guide, they can sense the time as nearly as they do. There is, however, some variation, depending upon the weather. Unseasonable warmth will bring the birds on prematurely, and continued cold will keep them back, or at least the majority of them. Yet even then there are often individuals in whom the instinct is so strong that they brave cold and storm and come on time. The problem of the origin and cause of migration still remains shrouded in mystery, which adds all the more interest to observation of it. It will be largely through gathering of data by many observers everywhere that we can hope to come to a better understanding of it.
The watching of the migration will give special pleasure if several observers in a locality work together. It is really very exciting to try to be the first to record the arrival of the various species. One has a sense of achievement in being the first to see and report the new appearance, especially if it is some very early or unusual one.
In the case of those who expect to go afield at this time with considerable frequency and regularity, I suggest that they write to the Bureau of Biological Survey, Washington, and secure data-blanks for re-cording migration. There is a column on the left where the names of species are to be put down in the order in which they are seen. In other spaces opposite can be given the dates when first seen, when at greatest abundance, and, in the case of those proceeding further, when last noted. This will not only furnish neat and convenient stationery for one's own records, but the copy returned to the Department at the end of the season will be a real contribution to science.
Quite a number of our hardier familiar land-birds winter in the Southern States and return to their familiar nesting-haunts comparatively early in the spring. Of some of these a few individuals are occasionally seen in Northern States in winter. Such species are the robin, bluebird, song sparrow, red-winged and crow blackbirds, meadowlark, kingfisher, cedar-bird, purple finch, woodcock, and various others. But the great majority pass on to Central or South America. On the return migration in spring, some come by the all-land route, through Mexico and Texas, but more of those that reach the eastern districts prefer to fly across the Gulf of Mexico. Of these, some take the easier route through Cuba or other islands of the West Indies to southern Florida. This route affords convenient resting-places to break the long journey.
The flight from Cuba to the Florida keys is only about one hundred miles, yet, when I cruised off the keys one April, I saw many flocks of small migrants flying low over the water headed for the land, some of which were almost exhausted. Yet it is surprising that the great majority of these migrants prefer to fly directly across the Gulf of Mexico to Louisiana, Mississippi, Alabama, Georgia, or northern Florida, without a single opportunity to rest. Many of them are feeble filet and during unfavorable weather the loss of life must be appalling.
From the Gulf States the time required to migrate to the latitude of New England, according to abundant data secured by the Bureau of Biological Survey, seems to be ordinarily just about one month. Some species move more slowly and take about six weeks, while a few do it in half that time. These estimates are based upon the average progress of a species as a whole, and not on what a lively individual might do. The dates of arrival which I shall mention are for the latitude of New York City and southern New England. From these, according to the rate of progress as above, one can approximate the time for arrival in other localities.
The migratory movement begins before there is much sign of real spring. In some years by the last week in February, if there should be a mild spell and thaw, the first early spring birds suddenly appear. Our hardy quartette are the bluebird, robin, red-winged blackbird, and song sparrow. Each of these is occasionally seen throughout the winter. About the tenth of March, though, is more usually their time of arrival. Should the weather continue cold and stormy up to that time, and then a decided warm wave ensue, these birds will arrive almost en masse, and simultaneously with them some that are usually due about the middle of the month. This was the case on the twelfth of March, 1907, when the deserted landscape of southern New England was suddenly alive with birds, which had arrived during the night. With the early four came crow blackbirds, meadowlarks, cedar-birds, phoebes, cowbirds, flickers, and an accession to the winter supply of crows, and probably others which I failed to note. Some of these are not ordinarily seen until the twentieth, or after.
The woodcock is due at this time, when one would think it impossible that there should be soft ground in which it could bore, or worms therein to keep it from starving. But if one will seek out open springs in warm sheltered spots on the edge of woods, with southern exposure, the reward may be the very pretty sight of the long-billed bird, in the rich hues of new plumage, flushing at close range and tamely alighting not far beyond.
Soon after the first woodcock wemay expect to en-counter small parties of fox sparrows along the road-sides or in the woods, and toward the end of March, the swamp, vesper, and field sparrows. Though the birds which have already arrived increase in numbers and the females, which are preceded by the males, have put in their appearance, additional species are slow to come, and meanwhile the winter birds are leaving for the north. Many water and raptorial birds arrive early, as will be told farther on.
During early April the tiny kinglets are in evidente. The golden-crown, which has been occasional in the winter, has become more numerous where there are evergreens, and now the ruby-crown has joined it. The former has yellow on the crown,— the male orange and yellow,— while in the other the crown-patch is fiery red and the female lacks that ornament entirely. We begin to see the purple finch in numbers, though sometimes it arrives earlier. The American pipit, in small numbers, which can be recognized by its habit of wagging the tail, runs about open, rather barren fields or hill-tops, picking up food. The first of the warbler host, the myrtle and yellow palm warblers, arrive.
By the middle of the month we are glad to greet the hermit thrush, though he does not yet condescend to sing for us, and the first straggling swallows, tree, bank, and barn,— which do not necessarily make a summer, for sometimes it snows after their arrival. Then, when they disappear, we fear that they have perished, for there is room for grave doubt as to whether individual birds caught too far north can run back for a time, as is the popular impression that they do. We may fear that a swallow without food in a snowstorm would not get very far, poor thing ! Though they perish, others in due time arrive, and people gladly imagine that they are the same ones. The birds have no warm Pullmans and dining cars in which to journey.
During the last days of April the great wave of migration, in middle latitudes, begins to be felt. In these days we see the first individuals of such typical summer species as the brown thrasher, towhee, whippoorwill, chimney-swift, and a few more of the warblers, especially the black-throated green, black and white, and oven-bird. By the second week of May everything is pouring in at once, and a list of arrivals would include about all the small birds not yet mentioned. By the twenty-fifth of May most of the birds which go farther north have passed on, the rear of the procession being brought up by the blackpoll in the opening days of June, though occasionally the migration is greatly retarded when the season is cold and backward.
During the periods of migration there are some things of value which may be learned, if students will bear them in mind. For one thing we need to know more of the effect of weather and storms upon birds. Hence it is well to make note of conditions of weather - wind, approximate temperature, and precipitation — in connection with the other observations. In time a series of such notes, especially from many observers, would be of great interest and value. Make record of birds killed by storms. Have an eye out, too, as far as possible, for the directions in which birds are seen migrating, their special lines of flight, if any. From this we may gain new information as to their movements.
Birds do not always, by any means, migrate directly north and south, as they are popularly supposed to do. There seem to be certain " rivers " of migration, we might call them, corresponding to the " lanes of navigation " used by trans-Atlantic steamships. River-valleys are notable highways of migration, as is the coast-line. Certain species are peculiarly limited in their distribution and migrate only along rather well-defined pathways, especially along the valleys of rivers or the sides of mountain ranges.
In some cases the course of migratory birds is locally deflected by conditions of topography. In illustration of this last it has been shown by Dr. L. B. Bishop, as a result of a long series of observations, that land-birds in migration following the Connecticut shore-line, when they come within sight of New Haven Harbor, are deflected and fly miles inland around this bay, rather than venture a mile or two across it.
For many' people the period of the spring migration is filled with exacting demands upon their time. We begrudge the hours of joy and sunshine in which we find ourselves cooped up indoors. I can still see myself writing examinations when the birds were warbling outside, literally gnashing my teeth in impotent vexation, Well, perhaps we appreciate the spring birds even thus more than though we could always be among them. Perhaps if we systematize the time, we can add to our opportunities. It may be a case of " early to bed and early to rise."
Much can be done even in a few odd moments from time to time. The birds in the spring migration are more in evidence than at any other period. They are on the move and in sight, they sing loudly and constantly, they invade the garden with their *el come presence and come to our very doors. Even from the window, if there are trees near-by, some have seen rare and interesting birds as when a friend of mine, one spring, from his windows was able, for the first time in his life, to study Tennessee warblers.
The main trouble with this delightful period is that it is too short. Before we realize, it has slipped away from us. Fortunately there are other good things in store. And if we have made good use of our opportunities with the swiftly-moving procession, we have gained a fund of experience and knowledge, of valuable notes, of delightful remembrance, which will remain to us as capital with which to enlarge our enjoyment.