108 General Notes. [^ 



Duck Hawks Wintering in the Center of Philadelphia. — On 



January 29, 1918, two Duck Hawks (Falco peregrinus anatum) were ob- 

 served circling about the tower of the Philadelphia city hall (517 feet in 

 height) situated in the midst of the business center of the city. My office 

 window on the sixteenth floor of the Widener Building about opposite to 

 the tower clock (361 feet from the ground) gave me an excellent opportunity 

 to observe them. How long they had been present before my attention 

 was attracted to them I cannot say. They undoubtedly took up winter 

 quarters on the tower on account of the large number of pigeons which 

 live about the building and upon which they fed. The exceptionally cold 

 winter also had its effect in reducing their normal food supply and forcing 

 them in from wilder regions. 



When first observed they were engaged in aerial evolutions apparently 

 purely for the joy of flying, now rapidly, now slowly, now chasing one 

 another and then a rapid swoop to one of the tower ledges, the leading bird 

 alighting and the other wheeling about the tower or out into mid-air. 

 These evolutions continued until dusk. 



During these flights they seemed to pay no attention whatever to the 

 many pigeons which darted here and there at terrific speed and in great 

 confusion. 



On three different occasions, however, hawks were observed eating a 

 pigeon on the lower ledge at the base of the clock, apparently standing on 

 it with both feet and tearing off the feathers which floated away on the air. 

 This seemed to be a regular preliminary to the beginning of each meal. 

 On one occasion a hawk flew across directly in front of the window from 

 which my observations were made carrying a large pigeon in its talons. 

 Its flight was perceptibly slow and labored as compared with its usual 

 grace and agility. On February 5 a hawk flew to the northeast tower 

 ledge with a pigeon which it proceeded to devour; hitherto the southeast 

 ledge had always been the place to which the quarry was carried. During 

 the early afternoon both hawks were noticed in flight about the tower 

 when they suddenly dived downward at terrific speed almost to the house- 

 tops and began a rapid darting flight among the chimneys, travelling 

 northeast over the city apparently on a pigeon hunt. 



Often they were seen to fly directly toward one another with a very rapid 

 flapping of the wings but in a labored manner so that they made very slow 

 progress, and then when almost breast to breast they would turn suddenly 

 and dive clown vertically. On February 6 I saw a hawk dive vertically from 

 the clock ledge in pursuit of a pigeon which passed on the wing at least 300 

 feet below but failed to secure it. Usually these failures seemed to be due 

 to the fact that two or more pigeons were pursued in an apparently hap- 

 hazard manner instead of the more logical method of singling out one bird. 

 When pursued en masse the pigeons invariably separated, scattering in all 

 directions and leaving the pursuer in a rather confused and puzzled condi- 

 tion and in doubt as to which individual to attack, resulting in his return 



