74 AVIFAUNA COLUMBIANA. 



nest in close woodland, but at other times no birds whatever are more 

 frequently under observation. There is a famous " Crow roost" across 

 the Potomac, some distance above the Chain Bridge, to which resort, 

 during the greater part of the year, " the blackening train of Crows to 

 their repose." Thousands of Crows from all parts of the country for 

 many miles around go to and from the place daily. As it lies directly 



Jif 



Fig. 53.— Bill of Ci-ow, nat. size. 



west of Washington, the consequence is that those beneath whose path 

 the city lies are seen flying west in the evening and east in the morn- 

 ing. The latter flight occurs in the gray of the dawn, and of course is 

 witnessed by few respectable persons, but the returning movement is 

 conspicuous. It begins early in the afternoon and continues until dark. 

 During all these hours a steady, ceaseless stream of the great black 

 birds pours along — hundreds and thousands of them, not in flocks, but 

 in a continuous train. On fair days they fly high and firmly ; on windy 

 days there is often much trouble, obliging the birds to tack and shift 

 until they are sometimes so weary that they are forced to alight on the 

 house-tops to gather strength to proceed. It happens that most of the 

 strong winds, particularly the cold ones of February and March, come 

 out of the west, thus directly opposing the progress of such birds as 

 pass over the city. Such "roosts" are well known in various parts of 

 the Eastern United States; but the impulse whose potency forces such 

 long daily journeys upon the birds is a mystery as yet unexplained. 

 Their scattering from the roost is of course in search of food, but the 

 puzzle is why they should find it necessary to return every night when 

 any other piece of woodland, one would suppose, should furnish equally 

 eligible accommodations for the night, [340] 



117. (149.) Corvus maritimus Bartr. (C. ossifragus of the original edition.) Fish 

 Crow. 



Eesident all the year round ; abundant, but less so than the foregoing. 

 It is also less wary and suspicious, and more closely confined to the 

 vicinity of the rivers. It is often confounded with the preceding ; but 

 some of the smallest and otherwise best-marked examples we have in- 

 spected have been those from this locality. [343] 



Note. — In the Proceedings of the United States National Museum, 

 18S0, p. 238, Mr. Eidgway records that a specimen of the European 

 Rook, Corvus fmgilegus, was seen by him in a maple tree on the grounds 

 of the Agricultural Department in August, 1870. It was very tame, 

 and flew laboriously, as if recently escaped from confinement. Nothing 

 farther has been learned of this estray. 



