30 AVIFAUNA COLUMBIANA. 



during the migratory season must have repeatedly heard the notes of 

 passing birds high overhead, invisible in the darkness. The distance at 

 which notes can be heard under these circumstances is surprising. We 

 have distinctly heard the notes of the Bobolink, in the daytime, when 

 the bird itself was beyond the range of vision. The loud honking of 

 wild geese while migrating is well known. 



A circumstance which has great influence upon the appearance of 

 birds in the District, as a perturbating element in conditions otherwise 

 natural, is the presence of a large city. The resulting modification in 

 the number of species and of individuals and in their habits is much 

 greater than formerly, now that the city has trebled its population within 

 twenty or twenty-five years, and suburban residences beyond actual 

 municipal limits have altered the face of the country very materially. 

 The general result, as usual, has been the entire extirpation of a few 

 species, and decided decrease in the numbers of many others. This is 

 strikingly shown in the cases of Ducks and other water- fowl, and of game 

 birds generally. The Chesapeake Bay and all its tributaries are specially 

 adapted to the winter residence of water-fowl, and still would be a favorite 

 resort did not the incessant persecution to which these birds are subjected 

 force them to seek safer quarters in the bays and inlets of more southern 

 shores. The same is true of various shy and solitary birds which have 

 gradually retired, wholly or in greatest part with the clearing up of the 

 forests, to more mountainous or other secluded and less accessible re- 

 gions. The Wild Turkey has been practically exterminated, though 

 still lingering near us; and so has doubtless the Sand-hill Crane. The 

 Pileated Woodpecker is nearly in the same predicament, though still seen 

 once in a while. The modification has no doubt been greater during the 

 period between the two editions of our List than in all time previously, 

 and we have been obliged to bear this constantly in mind in remodeling 

 our notices of the species. Nevertheless, the pertinacity with which 

 some birds hold their ground is surprising; the common Partridge, for 

 example, being still found near the city, though so incessantly perse- 

 cuted. A few birds appear to increase in numbers with the opening up 

 of country, their insect fare, probably, beng improved, and some of 

 their natural enemies being restrained. Examples of change of habits 

 consequent upon the settlement of the country are afforded by the 

 Swallows, Swifts, and some other species. The Chimney Swift formerly 

 bred in hollow trees, but uow finds chimneys entirely eligible. The 

 Barn Swallow now breeds entirely on the rafters and beams of out- 

 houses; the Purple Martin gives preference to the boxes now every- 

 where placed for its convenience; the Cliff Swallow has abandoned its 

 rocks for the eaves of houses. The Bluebird, House Wren, and Pewit 

 Flycatcher are almost as domestic ; we have the Chip-bird in the trellis, 

 and even the Owl in the belfry. 



A very disturbing element has been introduced since our List origi- 

 nally appeared; namely, the European Sparrow. Though nearly every 



