470 BULLETIN 17 6, UNITED STATES NATIONAL MUSEUM 



coloration, except that the feathers of the upper parts are margined 

 with bufFy, much more narrowly than in the juvenal plumage, and 

 the rectrices are exactly like the adult males. A female, from Los 

 Leones, Sinaloa, March 22, 1934, which has acquired the complete 

 juvenal plumage, has feathers of upper parts margined just as 

 broadly with cinnamon-buff, as the young male in partial juvenal 

 plumage, but differs in having a fully developed tail, just like the 

 adult females. Consequently, the differences of the sexes can be 

 determined in every plumage." 



Young males begin to acquire some of the bluish-green feathers in 

 the throat patch early in their first year but, apparently, do not 

 acquire the full bluish-green gorget and the metallic bronze-green of 

 the breast and sides until the first annual molt the next summer, when 

 old and young become indistinguishable. 



Food. — The broad-billed hummingbird evidently lives on similar 

 food to that of other members of the family, the nectar of flowers and 

 the minute insects that the flowers attract. Mr. Moore (MS.) men- 

 tions the red flowers of the ocotillo as attracting it and seeing it 

 feeding in the beds of the paint brush, but probably any brightly 

 colored blossoms would serve equally well as feeding places. He 

 says : "A small shrub, the 'tavachin,' flaunts an extraordinary flower, 

 resembling the royal poinciana, and fairly startles one with its scar- 

 let glory. Belonging to the genus Caesalpinia or Poinciana., it pro- 

 vides the favorite rendezvous for Cynanthus^ as well as many species 

 of butterflies. The tiny homesteader made many excursions to obtain 

 food from this plant, whose vivid red and yellow fl'owers flamed in 

 the sunlit spaces across the sandy arroyo. She apportioned part of 

 her time to the yellow flowers of a huge opuntia, which hung out 

 perilously over her side of the arroyo. During the hottest period of 

 the day she drowsed on a branch of the nesting tree, within 10 feet 

 of the nest, not usually making food rounds until 3 : 30 in the after- 

 noon. Between each round she would spend several minutes resting 

 in the nest tree. At the beginning of each circuit I timed the aver- 

 age of inception, which was approximately 15 minutes, and each time 

 she visited apparently every flower over again. A few less con- 

 spicuous blooms were also probed." 



Cottam and Knappen (1939) examined four stomachs collected in 

 Arizona, which "show that the bird feeds primarily on small insects 

 and spiders." In their summary they mention fragments of plant 

 lice, leafhoppers, jumping plant lice, miscellaneous bugs, root gnats, 

 flower flies, miscellaneous flies including dance flies, ants, parasitic 

 wasps, miscellaneous Hymenoptera, some undertermined insects, spi- 

 ders, daddy-longlegs, and pollen grains. 



Behavior. — Referring to the behavior of the female in the defense 



