CHIMNEY SWIFT 281 



standing- on the ground, does not make this adjustment, for he does 

 not take into account the instantaneous tiltino: of the bird. 



The question was definitely settled by Myron F. Westover fi§8^, 

 who demonstrated by motion photography that '-'■there luas no instance 

 where there ^oas any alternation of loing -movement ; the wings mo-\'e 

 in unison as do those of other species of birds." _jDr. Chapman 

 appends an editorial note to the article: "Mr. Westover's film was 

 shown in the American Museum to the members of the Bird De- 

 partment who agree that it demonstrates beyond question the truth 

 of his conclusions." 



There is a difference of opinion also among observers as to whether 

 the swift, when collecting nesting material, breaks off dead twigs 

 with its feet or with its beak. Coues (1897), questioning the cor- 

 rectness of a drawing by Fuertes representing the bird snapping off 

 a twig with its feet, says: "We have always supposed the bird se- 

 cured ih.& object with its beak, as it dashed past on wing at full 

 speed; or at any rate that has been my own belief for more years 

 than I can remember. But Mr. Fuertes vouched for the correctness 

 of his representation from actual observation. The question being 

 thus raised, I set it forth recently in a query inserted in one of our 

 popular periodicals, asking for information." 



There are six replies to Coues' query printed in The Nidologist 

 (vol. 4, pp. 80, 81), five of which are in accord with his opinion, 

 while one is against it, as is one more reply published in The Osprey 

 (vol. 1, p. 122). Dr. Coues declares that "these leave the case still 

 open !" 



More recently Shelley (1929), from an ample experience of 13 

 uninterrupted years of observation of swifts at close range, states 

 unequivocally that the.v "gather their nesting material * * * 

 with their feety He adds: "I never yet observed a Swift grasp or 

 carry a twig in its beak." 



Mr. Shelley's well-weighed opinion added to that of Mr. Fuertes, 

 whose accuracy and skill in observing birds have never been sur- 

 passed, should be accepted with confidence until motion photography 

 shall prove or disprove the correctness of their view, although the 

 swift may adoj^t both methods of collecting nesting material. 



We may recall that Audubon (1840) appears to have had no 

 doubt upon the question, for he says: "They throw their body sud- 

 denly against the twig, grapple it with their feet, and by an instan- 

 taneous jerk, snap it off short, and proceed with it to the place 

 intended for the nest." 



Although without much doubt swifts pluck off twigs with their 

 feet, they may find it convenient to arrive at the nest site with their 

 feet free to grasp the wall of the chimney. To gain this end, it is 



