384 BULLETIN 17 6, UNITED STATES NATIONAL MUSEUM 



Sun-bathing is less frequent and appears to be an individual rather 

 than a general custom. Shortly after noon on a hot July day I saw 

 an immature male Anna's hummingbird alight on a bare patch of 

 ground arid, heading directly away from the sun, stretch out flat on 

 the soil with wings fully extended a7id the feathers of the back 

 erected. Again, about two months later, at about the same time of 

 day, the identical action was repeated on the lawn by the same indi- 

 vidual. In both instances he remained on the ground less than a 

 minute. 



As to the intelligence of hummingbirds, I find no evidence to sup- 

 port W. H. Hudson's contention that they resemble insects more than 

 birds in their mental processes. Their tameness cannot reasonably 

 be attributed to mere stupidity, but rather to justified confidence in 

 their own agility and swiftness, and perhaps also in human good will, 

 since their power of discrimination is shown by their noticeable war- 

 iness toward cats. In their disposition and temperament humming- 

 birds are hardly comparable to any other birds but remind one most 

 strongly of chipmunks. 



Voice. — Of the seven species of hummingbirds found in the State of 

 California, Anna's is the only one that may be said to possess a song. 

 The "song" can hardly be called melodious, being a thin, "squeaky 

 warble suggestive of filing a saw. Nevertheless, it is delivered with 

 fervor and remarkable persistence, with little regard for season. This 

 song, which in addition to its use in courtship seems to serve the pur- 

 pose of a genera] greeting or challenge, or sometimes merely a form 

 of self-amusement, is peculiar to the males, who begin practicing it 

 almost before their gorgets have started to develop. During the 

 rendition, which often lasts for a rather long time, the bird leans for- 

 ward on his perch, extends his neck, and holds his bill tightly closed, 

 as far as can be detected at a distance of several feet. The clear, 

 high-pitched, 2- or 3-syllabled whistling call of the male Costa's 

 hummingbird, though less persistently used, appears to be entirely 

 analogous to the Anna's song. 



The ordinary notes common to both sexes are similar to those of 

 other species. They consist of the feeding note, a mechanical "tick" 

 or a more liquid chirp uttered at measured intervals as the bird goes 

 from flower to flower ; a similar note repeated more rapidly and ani- 

 matedly while perching and often accompanied by a wagging of the 

 head from side to side, expressing excitement or warning to tres- 

 passers; and the shrill twittering, which indicates a chase or skirmish. 

 The begging call of the newly fledged young is much like that of 

 other young birds. 



Field marks. — Anna's hummingbird is the largest species found 

 within its ordinary range, but there is integradation in measurements 

 with all but the calliope hummingbird, whose small size is usually 



