74 BULLETIN 17 9, UNITED STATES NATIONAL MUSEUM 



all tile fruit was eaten in the months from September to January, 

 inclusive." 



Behavior. — Henshaw (1875) quotes some Colorado notes from C. E. 

 Aiken, which give a good idea of the behavior and appearance of 

 Cassin's kingbird as compared with the Arkansas kingbird ; he writes : 



Although these two birds resemble each other so closely in the skin, in life 

 there are marked differences in notes and actions that even a novice cannot 

 fail to notice. Vcrticwlis is a nervous, fickle creature, seldom remaining lonj; 

 in one place, and flying with a quick fluttering motion of the wings. It is 

 also exceedingly noisy, its notes being a high pitched chatter. Vociferans, on 

 the other hand, is a more matter of fact bird, often sitting quietly for a long 

 time in the same place, and its notes are harsher and less frequently uttered. 

 Its appearance, too, when alive conveys the Impression of a heavier, stouter 

 built bird. When migrating, and indeed at other times, it appears to be restricted 

 to the parks of the foothills, alighting upon weed stalks and low bushes, 

 from which it sallies forth occasionally to seize some passing insect. 



Henshaw (1875) also says: "Though found in the same locality, 

 individuals of the two species never meet without displaying their 

 natural emnity. At Camp Grant, my attention being called by the 

 loud outcries of several of these birds, I found that a female and 

 several young of the Arkansas Flycatcher were the objects of a 

 savage assault by a pair of the present species. The mother bird 

 most gallantly stood up and fought for her offspring, repelling each 

 attack with a brave front, and retaliating to the best of her ability. 

 T watched them until I saw that the assailants, having fairly got 

 worsted, were glad to retire, and leave the family to gather together 

 in peace." 



This behavior is quite different from that noted by Mr. Dawson 

 (1923) in California, referred to under nesting; evidently there is 

 considerable individual variation in behavior in this, as in many 

 other species. Some observers state that this kingbird does not 

 persecute hawks and crows so much as the other kingbirds do, but 

 others report to thie contrary. For example, E. A. Mearns (1890) 

 says: "On the Mogollon Mountains I saw them attack Crows and 

 Western Red-tailed Hawks and drive them from the neighborhood 

 of their nests after the spirited fashion of the Eastern Kingbird." 

 Doubtless all kingbirds would do this. Florence A. Merriam Bailey 

 (1896) writes: "Mr. Memam told me that when he was plowing 

 and the Blackbirds were following him, two or three of the 'Bee- 

 birds,' as he called them, would take up positions on stakes over- 

 looking the flock; and when one of the Blackbirds got a worm that 

 he could not gulp right down, a Beebird would dart after him and 

 fight for it, chasing the Blackbird till he got it away. For the time 

 the Flycatchers regularly made their living off the Blackbirds as 

 the Eagles do from the Fish Hawks." 



