INTRODUCTION OF BIRDS. 119 



Nature sets bounds to tlie disproportionate increase of birds^ 

 whilst at the same time, by the multitude of their resources, she 

 secures them from extinction through her own spontaneous agen- 

 cies. Man both preys upon them and wantonly destroys them. 

 The dehcious flavor of game-birds, and the skill imphed in the 

 various arts of the sportsman who devotes himself to fowling, 

 make them favorite objects of the chase, while the beauty of their 

 plumage, as a mihtary and feminine decoration, threatens to in- 

 volve the sacrifice of the last survivor of many once numerous 



found at the foot of the tower. They had been killed in the course of the 

 night by flying against the thick glass or grating of the lantern. 



From an article by A. Esquiros, in the Revue des Deux Mondes for Septem- 

 ber 1, 1864, entitled La vie Anglaise, p. 119, it appears that such occurrences 

 as that stated in the note have been not unfrequent on the British coast. " In 

 1877," says a French journal, "a curious phenomenon was witnessed at the 

 lighthouse of the Basquets in the English Channel. One night, between the 

 hours of 11 P.M. and 4 a.m., quantities of birds — woodcocks, blackbirds, 

 thrushes, and swallows — came flying about the light. Many dashed them- 

 selves against the glass and were killed. More than a hundred swallows were 

 found dead in the morning ; but the larger birds for the most part avoided 

 actually striking the glass, and only fluttered about in the surrounding light." 

 Are the birds thus attracted by new lights, flocks in migration ? 



Migrating birds, whether for greater security from eagles, hawks and other 

 enemies, or for some imknown reason, perform a great part of their annual 

 journeys by night ; and it is observed in the Alps that they follow the high- 

 roads in their passage across the mountains. This is partly because the food 

 in search of which they must sometimes descend is principally found near the 

 roads. It is, however, not altogether for the sake of consorting with man, or 

 of profiting by his labors, that their line of flight conforms to the paths he has 

 traced, but rather because the great roads are carried through the natural 

 depressions in the chain, and hence the birds can cross the summit by these 

 routes without rising to a height where, at the seasons of migration, the cold 

 would be excessive. 



The instinct which guides migratory birds in their course is not in all cases 

 infallible, and it seems to be confounded by changes in the condition of the 

 surface. I am familiar with a village in New England, at the junction of two 

 valleys, each drained by a mill-stream, where the flocks of wild geese, which 

 formerly passed every spring and autumn, were very frequently lost, as it was 

 popularly phrased, and I have often heard their screams in the night as they 

 flew wildly about in perplexity as to the proper course. Perhaps the village 

 lights embarrassed them, or perhaps the constant changes in the face of the 

 country, from the clearings then going on, introduced into the landscape 

 features not according with the ideal map handed down in the anserine fam- 

 ily, and thus deranged its traditional geography. 



