58 BULLETIN 17 0, UNITED STATES NATIONAL MUSEUM 



it had fallen throe feet — she transferred it to her talons and lit on the 

 dead tree to eat it." 



On another occasion "the male came in from the east with a small 

 bird, circled over the talus slope several times, and finally swooped 

 in almost over the nest shelf, but 10 feet above it, without making a 

 sound. The female came off in a moment, circled up under the male, 

 giving the feeding call, and the bird was transferred from talons to 

 talons." 



Behavior. — The flight of the duck hawk is a marvelous exhibition 

 of grace, agility, and speed. Few of its intended victims can escape. 

 It seems to have speed in reserve, for a quick dash over, under, or to 

 one side of its victim before delivering the death blow. Its long, 

 pointed wings whip the air with quick, powerful strokes, giving it the 

 momentum for the final dash on half-closed wings, as it swoops down 

 on its prey with the sound of rushing wind. 



About its aerie it flies swiftly, with from two to four or five quick 

 strokes, followed by a longer period of sailing. I have read that it 

 seldom soars, but I have often seen it do so ; I have seen it sail, or soar, 

 for a long distance on horizontal wings and spread tail, with little or 

 no wing movement, rising, falling, or turning at will. Sometimes, 

 when coming down from a great height, it makes a swift "nose dive" 

 at terrific speed, with wings flexed and primaries pointing straight 

 backward. It is a graceful master of the air at all times. 



These falcons often indulge in playful flight for exercise or sport. 

 Delos E. Culver (1919), writing of two that were playing about the 

 tower of the Philadelphia City Hall, says: "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 lower ledges, the leading bird alighting 

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

 evolutions were continued until dusk. * * * 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 down vertically." 



Dr. Wetmore (1933) writes: 



When not hungry, the duck hawk, feeling its superior strength, frequently 

 indulges in harmless play at the expense of its bird neighbors. 



Often I have seen them flying along the river channels, driving ahead of them 

 a motley flock of blackbirds, herons, avocets, and other birds, herding them in 

 disorder like sheep, but without offering to harm them. Again, as night herons 

 flew ahead of my launch, a duck hawk would dart at them repeatedly, forcing 

 them down lower and lower, until finally, with protesting squawks, they struck 

 the water. They were not allowed to rise, but had to swim into the shelter of 

 the willows to escape. 



One pleasant afternoon in fall I heard a great roaring of wings overhead and 

 looked up to see a cormorant that a few minutes before had been soaring peace- 



