WHITE-EARED HUMMINGBIRD 461 



the ends of their sheaths. Four days later the green portions of the 

 contour feathers become visible; but still the black skin of the little 

 birds is not entirely covered. They are 16 days old before the wing 

 plumes begin to push from the ends of their sheaths, and 18 days of 

 age before the rectrices escape their horny covering. The nestlings 

 are brooded nightly by their mother until 17 or 18 days old, when they 

 are well clothed with feathers. If frightened, they may fly from the 

 nest at the age of 23 days, but if unmolested they do not depart until 

 their twenty-sixth day. At the time of their departure they fly with 

 strength and ease and never again return to the shelter of the nest. 

 The fledgling white-ears closely resemble their mothers, except that 

 the white postocular line is slightly tinged with buff. It is perhaps 

 significant that these hummingbirds raised during cool and frosty 

 weather in the highlands remain in the nest several days longer than 

 the Rieffer's hummingbirds of the warm lowlands, which quit the 

 nest at the age of 18 to 23 days. 



The white-eared hummingbirds may raise two broods in a season. 

 One female, which succeeded in raising a single nestling in her first 

 nest, built a second structure, 40 feet from the first, during the week 

 after her fledglmg took wing. She had a busy week, for she satisfied 

 the hunger of the young hummingbird in the intervals of working on 

 the new nest. As a result of her divided attention, the second nest 

 was far less perfect than the first. It was shallower, thinner walled, 

 and carelessly finished; in fact, it seemed scarcely completed when 

 the first egg was laid in it, ten days after the fledgling departed his 

 cradle. 



From my tent I watched this hummingbird as she incubated her 

 second set of eggs. Her fledgling, a young male, was now 40 days old 

 and had been out of the nest just two weeks. In size he was scarcely 

 to be distinguished from his mother. His bill seemed slightly shorter, 

 and his back was not such a bright green, because many of the 

 feathers still bore the downy-brown tips which characterize the 

 nestling plumage. He flew very well, and spent much time suckmg 

 nectar from the red blossoms of the salvias, which I could watch 

 through the right window of the tent. When not occupied with 

 visiting the flowers, he rested among the low branches of a little 

 bushy thicket about 30 feet from his mother's second nest. Here she 

 came to feed him during her absences from the eggs, in spite of the 

 fact that he could now forage very well for himself. Once, indeed, 

 he visited the flowers while his mother gathered food for him, then 

 came to supplement his meal by what she had to offer. Perching be- 

 side him upon a low twig, she delivered the food, as always, by 

 regurgitation, which she began with very violent convulsive move- 

 ments of the body. He was a well-behaved youngster and never came 



