10 BULLETIN 17 4, UNITED STATES NATIONAL MUSEUM 



and poison ivy {Rhus radicans) equaled 12.67 percent. Fragments 

 of an unidentified gall formed 1 percent of the content. 



BehaA}ior.—ThQ uniform direct flight of the ivorybill resembles 

 that of the red-headed woodpecker more than it does the swooping 

 undulating flight of the pileated, and this general resemblance is em- 

 phasized by the large amount of white in the wings. When viewed 

 from below, the long pointed tail is quite conspicuous and the wings 

 seem very narrow because the black portion is so much more con- 

 spicuous than the white, which apparently cuts off the whole rear of 

 the wing. This is perhaps not so conspicuous when viewed from the 

 side, but even so it is remarkable how ducklike the bird can appear 

 as it flies swiftly and directly up a lagoon, so much so in fact that cer- 

 tain Louisiana hunters have told me that they have even shot at them 

 under such circumstances, mistaking them for ducks. In this connec- 

 tion Audubon's (1842) description of the flight of the ivorybill is 

 quite misleading : "The flight of this bird is graceful in the extreme, 

 although seldom prolonged to more than a few hundred yards at a 

 time, unless when it has to cross a large river, which it does in deep 

 undulations, opening its wings at first to their full extent and nearly 

 closing them to renew the propelling impulse. The transit from one 

 tree to another, even should the distance be as much as a hundred 

 yards, is performed by a single sweep, and the bird appears as if 

 merely swinging itself from the top of the one tree to that of the 

 other, forming an elegantly curved line." 



Voice. — Concerning the voice of the ivorybill there seems to be 

 considerable agreement in that the ordinary note sounds like a single 

 blast from a tin trumpet or a clarinet. In the words of Audubon, 

 "Its notes are clear, loud, and yet rather plaintive. They are heard 

 at a considerable distance, perhaps half a mile, and resemble the 

 false, high note of a clarionet." According to Hoyt (1905) : "It is 

 a single note and resembles the w^ord Schwenk, at times keyed very 

 high, again soft and plaintive, it lacks carrying capacity and can 

 rarely be heard over 100 yards on a still morning, while the harsh 

 notes of the pileated woodpecker can be heard a full mile." Allen 

 and Kellogg (1937) state that anyone can produce the sound very 

 accurately by using only the mouthpiece of the clarinet. They ques- 

 tion whether the loudest calls can be heard half a mile : 



It is doubtful, however, if tlie loudest calls can be heard, under normal condi- 

 tions, for a quarter of a mile, and some of the weaker ones are scarcely audible 

 at 300 yards. However, when we tested the carrying power of one of our 

 recordings of the common alarm note, kent, amplified until it sounded to our 

 ears normal at about one hundred feet, the call was distinctly recognizable 

 at a distance of 2,500 feet directly in front of the amplifier with no trees or 

 buildings intervening. At a 45-degree angle the sound was not recognizable 

 at half this distance. The birds are so often quiet for such long periods 

 that we can scarcely agree with Audubon's statement that "the bird spends 



