10 



THE OSPREY. 



BLUE-FACED BOOBV, WITH NEST AND ECiGS. 

 Photographed from life, on the Revillegigedo Islands. 



Species will often be noted at a locality from lOO 

 to 600 miles from the one where it was observed 

 the day before. It is well known that our small 

 land birds, as well as larger ones, cross the great 

 lakes and the Gulf of Mexico. 



Sea captains have reported flocks of them from 

 100 to 500 miles east of Nantucket, anoarently 

 cii route from the Bahama Islands to Nova 

 Scotia. They have, however, often been seen 

 alighting upon floating sea weed or other objects 

 to rest awhile when far out at sea. It is said that 

 many small birds take passage across the Medi- 

 terranean on the backs of cranes and storks. 



The poet also noticed that a warm, damp night 

 is conducive to bird migration. Recent investiga- 

 tions confirm his statement. It is found that 

 when the proper time arrives for the spring 

 movement toward the north, after a night of low 

 barometer and high thermometer the morning 

 air will be filled with songs of new arrivals. 



Birds possessed of superior strength and 

 velocity of wing and that depend upon their 

 speed in flight to escape from their enemies and 

 also .gather their food while on the wing, as swal- 

 lows, swifts, and hawks, migrate during the day 

 and rest at night. An English naturalist states 

 that the common black sw-ift of Europe has been 

 known to attain to the speed of 276 miles an 

 liour. Doubtless, when the exact time of the 

 American chimney swift is taken it will be found 

 to be equal to that of any foreign species. Few 

 liirds, however, are so fleet. Wild geese, for in- 

 stance, rarely exceed go miles an hour. 



Certain feathered tourists, of a bold and rest- 



less disposition, travel either by day or by night. 

 Kobins, bluebirds, finches, crossbills, and iark.^ 

 belong 10 this class. Neither do they always make 

 l"ng nights, excepting in crossing large bodies 

 ii water or barren tracts of land, but nit along, 

 ' eding as they go, and perhaps averaging from 

 15 to ,;o miles a day. Whether they make long 

 flights or not depends largely upon the weatiier. 

 In autumn a cold storm will drive them rapidly 

 ||> the south; and in the spring, if their return to 

 iiicir nesting places has been retarded by un- 

 i.Lvorable climatic conditions, a general warm 

 wave will send them far to the, north in a single 

 flight. 



Crows, blackbirds, bobolinks, pigeons, wild 

 mese, and ducks migrate mainly in flocks. Most 

 '■I our land birds move in waves, in which they 

 .ne scattered over vast areas, only a few being 

 -len in a place, but probably all keeping in touch 

 most of the time, by sight or hearing, with the 

 ,L;eneral movement. The procession generally 

 straggles along for days in passing any point of 

 oliservation. 



Birds also dififer in regard to the distance of 

 their annual journeys. The white owl, snow 

 bunting, butclier birds, tree sparrows, and red- 

 poll linnets of the arctic regions are content with 

 a visit to the Northern United States during the 

 severest part of the cold season. Many of the 

 common summer residents of the latitude of the 

 L;reat lakes go but little south of the Ohio River, 

 while others resort far to the southland. The 

 barn sw.illow, chimney swift, purple martin, in- 

 ili.go buntmg, orchard oriole, wood thrush, 

 iiighthawk, and rose-breasted grossbeak are 

 Known to extend their tours beyond the national 

 boundary. Some of the forest warblers that nest 

 in .Alaska and in the vicinity of Hudson Bay are 

 said to journey hundreds of miles beyond the 

 equator. 



All birds do not migrate merely because they 

 prefer a moderate temperature. It is often an 

 exoediency of subsistence. 



Lieutenant Gteely, while stationed at Grinnell 

 Land, noted that the geese, ducks, and other 

 aquatic birds that rear their young in the Frigid 

 Zone move southward as soon as their food 

 supplv is cut olT by the freezing of the mud and 

 water. Doubtless one reason of the vernal mi- 

 gration is the necessity of locating their nests 

 within regions abounding in summer with the 

 larv;e of insects specially adapted to the nourish- 

 ment of their tender broods. There are birds, 

 nevertheless, that do not migrate at all, at least 

 so far as the species are concerned. Grouse, 

 (luail, nuthatches, chickadees, bluejays, hairy and 

 downy woodpeckers, and most species of hawks 

 and owls remain throughout the year in the 

 Northern States. In the latitude of Kentucky, 

 robins, bluebirds, thrushes, and many other birds 

 that are elsewhere migratory are permanent resi- 

 dents. 



Birds ^Iso vary as to the time of their migra- 

 tions. The first to come in the spring, robins, 

 bluebirds, blackbirds, and song sparrows, are the 

 last to leave us in the fall. Later arrivals, as 

 orioles, martins, swallows, and wrens, take their 

 departure early in the season. The bobolink is 

 usuallv the last to appear and the first to dis- 

 apnear. .\ffer the oat crop of the north has been 

 h->rvested. he at once sets out for the rice fields 

 of the south. 



In the sprinc: the males of nearlv all snecies 

 usually iirecede the females. In the early mi- 



