The Montgomery advertiser., 1906-11-18
By B. 8. Bowdish. Special Inspector
 Wild Birds, United states Depart
ment of Agriculture.

Wild Birds, United states Depart
 ment of Agriculture.
 About this season there are likely to
 be published newspaper accounts Of
 birds striking a lighthouse in great
 numbers in a single night or perishing
 in a sudden storm. These stories call
 the attention of the public to the won-
 derful journeys that great numbers of birds perform semi-annually.
 For many years much careful data
 have been gathered on the manner Tn
 which migration is performed, both oy
 the Biological Survey of the united
 States Department of Agriculture ana
 by independent observers The Bureau
 of Biological Survey has supplied all observers who were willing to cooper
 ate with blank schedules spring and
 falI. to be filled In with the date of arr
 rival of each species, the number hrEt seen. the second date on which the species was seen, the date, when 1t be- came common, the date when t was
 last seen. Gin spring for species whicn
 passed entirely through the loeallty
 to more northern breeding grounds, ana in fall for migrants so passing ana TOT summer residents that go entirely out of the locality for the winter), and
 some other data.
 These observations have established | the fact that the great majority or 1 birds seen in any one locality during the year perform a northerly move
 ment in spring and southerly move
 nent in fall, and that these movements are of considerable regularity as to dates. Unusually backward weather Tn spring may retard migration. while | cold and stormy weather in fall has a tendency to accelerate the movements of southward journeying birds. but In average birds the first appearance Of
 species in spring or fall seldom varies | much more than a week. It was long
 supposed that birds which never entire- Nv disappeared from locality were only partially or non migratory. For instance, in Southern New York and | New Jersey the crow and the robin are l represented by some individuals Tn most localities throughout the year. and it was supposed that some oirds ! remained D srmanent residents, while ! the majority migrated. Accumulating data, however, has given good reason ] to believe that the individuals seen m 1 n given locality in winter are not the ones which bred there, but are birds which, having nestled further north, have gradually replaced the summer
 birds in the fall migration. as the lat
 ter moved leisurely south,
 One of the features that has doubt | lrss added to the difficulties in pene- | trating the mysteries of migration IS the fact that many birds migrating fly | chiefly by night On clear nights these migrating birds fly at such helShtS that heir calls are but fainty heard, | If at all, by the alert watcher while | their small forms are only occasionally seen. Birds have been seen through telescopes that were pointed at the | race of the moon. crossing the range | of vision at a height of mile or more. ] on dark and cloudy nights they fly much lower, and In storms are liaDle l to b, come absolutely bewildered' and at l such times they call constantly to each other. Flying low on these cloudy | nights the birds are often dazed by the lamps of lighthouses. and, striking against them in great numbers are ! killed or maimed.
 All tncse things and many more on
 servatiou has taught regarding miEra-
 tIon. As to It's causes, the best We car vel do is to speculate. It was formerly ! thought that a cold drove the birds in fall to seek a warmer climate while attachment to their summer home im- pelled them, to return to 1t with the l coming of mild ~wea ther aGain m spring. It Is reasonable to believe tha; attachment to a given summer home has much to do with the northwaro