382 BULLETIN 17 6, UNITED STATES NATIONAL MUSEUM 



has a slight suggestion of the rustling of silk. In wet weather, how- 

 ever, one may often hear from a flying hummingbird a sort of clap- 

 ping noise of short duration, as if it were striking its wings to- 

 gether to rid them of moisture. 



The sense of hearing, like that of sight, is keen, and a slight 

 crunching of fallen leaves will evoke an attitude of alert apprehen- 

 sion, just as it does in many other wild creatures. The reaction 

 to a sharp noise, though, is likely to be merely a nervous start, 

 instead of the immediate flight, which is precipitated by any abrupt 

 visible movement. This latter response is so invariable that it may 

 well be regarded as a reflex rather than a volitional action. There 

 seems to be no convincing evidence that the sense of smell plays 

 any part in the discovery of food. A perfumed green-wrapped vial 

 of sugar syrup attracted no attention, though a nearby unperfumed 

 red- wrapped vial was quickly investigated. Some of the most heav- 

 ily scented flowers, such as the jasmine and the large white blossom 

 of the cactus Trlchocereus spachiamis^ are comparatively neglected. 

 Sense of location is very well developed, and when a bottle of syrup 

 that has been regularly visited by a hummingbird is moved with its 

 support to a different part of the grounds, the bird upon returning 

 will hover in the exact spot from which the bottle was removed, often 

 making several trips before finally becoming convinced. 



Most writers have credited hummingbirds with extreme quarrel- 

 someness among themselves and a tyrannical disposition toward 

 other birds. Careful observation has convinced me that their pug- 

 nacity has been greatly exaggerated, especially with reference to 

 birds of other kinds. I believe that a hummingbird pursues other 

 birds for exactly the same reason that a small dog will run after any 

 passing vehicle, but immediately lose interest in it when it stops. 

 Even the smallest passerine birds show no fear of the hummingbirds, 

 nor are they molested if they fail to enter into the spirit of the 

 game. Furthermore, I have often seen Anna's hummingbirds forced 

 away from their sugar syrup by house finches or Audubon's warblers 

 without the slightest show of resentment. Of course, a humming- 

 bird that has preempted a certain territory resents any trespassing 

 by other hummingbirds, who usually seem to recognize his rights 

 and seldom dispute them; it is when an interloper resists eviction 

 that the most earnest hostilities occur. Among the migrants in 

 spring and among the immature birds late in summer, however, the 

 constant chases and skirmishes appear to be carried on in a spirit of 

 sport much more than of spite. 



Probably because of their constant association among the flowers, 

 hummingbirds show little fear of bees. I have sometimes seen an 

 Anna's hummingbird, in order to reach a supply of sugar syrup, 

 thrust its bill through a struggling mass of the insects. In contrast 



