324 BULLETIN 17C, UNITED STATES NATIONAL MUSEUM 



bird, and its flight, though swift, is somewhat slower in proportion to 

 its size than that of the smaller species; its wing strokes are less 

 rapid, and it indulges in occasional periods of sailing on set wings, 

 much after the manner of a swift. 



F. H. Fowler (1903) writes of one that he saw: "Its motions are 

 unlike any other hummer I have ever seen as its wings did not hum 

 in the manner that has given this family its name, but cut the air 

 with strong, firm, wing beats. Its flight was erratic, like that of the 

 hummingbird moth, and at times like that of a bat. It would even 

 soar, or sail for a few feet. It was not very shy, but when it made up 

 its mind to go it w^ould flit away on an erratic course without the 

 slightest warning." 



Mr. Poling (1890) observes that "their flight is exceedingly rapid 

 at times but they often fly slowly so that the wings can be easily 

 seen during the beats. The noise made by this bird's wings during a 

 rapid flight is not like the buzzing of the small Hummer's wings, the 

 beats being more slow and distinct, without any buzzing noise." 



Like many other hummingbirds, the Rivoli is very quarrelsome; 

 those that we watched, as mentioned above, were evidently quarreling 

 with the bluethroats. And Mr. Ridgway (1892) quotes the following 

 remarks of Mr. Salvin, who was trying to collect a specimen of this 

 species: "Another Humming Bird rushes in, knocks the one I covet 

 off his perch, and the two go fighting and screaming away at a pace 

 hardly to be followed by the eye. Another time this flying fight is 

 sustained in midair, the belligerents, mounting higher and higher 

 till the one worsted in battle darts away seeking shelter, followed 

 by the victor, who never relinquishes the pursuit till the vanquished, 

 by doubling and hiding, succeeds in making his escape. These fierce 

 raids are not waged alone between members of the same species. 

 Eugenes fulgens attacks with equal ferocity Amazilia dumerilii, 

 and, animated by no high-souled generosity, scruples not to tilt with 

 the little Trochilus colubrisy 



Voice. — Mr. Poling (1890) says that their "note is a twittering 

 sound, louder, not so shrill, and uttered more slowly than those of 

 the small Hummers." 



Field marks. — The large size of Rivoli's hummingbird and its man- 

 ner of flight will distinguish it from all except the blue-throated 

 hummingbird. The adult males of these two species may be easily 

 distinguished by the different color patterns, if the bird is near 

 enough ; the bluish-purple crown, the brilliant green throat, and the 

 glossy black breast of the Eivoli are very different from the greenish 

 crown, dull blue throat, and grayish-brown breast of the blue- 

 throated. More conspicuous at a greater distance are the broad 

 white tips of the three outer tail feathers of the blue-throated, as 



