BROAD-BILLED HUMMINGBIRD 469 



Eggs. — Two eggs seem to be the usual, if not the invariable, rule 

 with the broad-billed hummingbird. These are pure white, without 

 gloss, and otherwise indistinguishable from the eggs of other hum- 

 mingbirds of similar size. The measurements of 27 eggs average 12.6 

 by 8.5 millimeters ; the eggs showing the four extremes measure 13.5 

 by 9.7, 13.4 by 9.8, and 11.5 by 7.5 millimeters. 



Plumages. — Mr. Moore says (MS.) : "The Moore collection contains 

 no young, actually taken from a nest, but a young male, obviously 

 not long out of the nest, was secured at the Guirocoba Ranch in ex- 

 treme southeastern Sonora on March 26, 1931. The bill is only half 

 the length of the adult, the tail the same, and the wings two-thirds, 

 the postnatal molt being about four-fifths complete on wings, tail, 

 entire upper parts, under tail coverts, and portions of the neck. Pos- 

 sessing very loose margins, the remiges are recurved. Two nearly 

 parallel feather tracts on the throat are sharply defined, because the 

 new feathers are still in their sheaths, and areas on throat and breast 

 are bare. 



"As to coloration, it is significant that the tail plainly shows the 

 male characteristics, being almost identically like the fully adult 

 male tail in miniature, revealing no white tips to the lateral rectrices 

 as in the female and having the median pair blue, tipped with gray, 

 instead of entirely bronzy green. The longest upper tail coverts show 

 full development and might easily be mistaken for the median pair 

 of rectrices. Therefore, it is clear that the sexes can be differentiated 

 in this species, even in the juvenal plumage, when a few weeks old. 

 Cinnamon-buff covers a large part of crown and occiput and reveals 

 much wider margins on the back than in the May, June, and Septem- 

 ber worn juvenal plumage. The lesser and middle wing coverts show 

 irridescent green, instead of bronzy. 



"On the under tail coverts, although the plumage is looser than in 

 the first winter plumage, the general appearance is immaculate white, 

 as in practically all adult magicus, contrasting them sharply with 

 Cynanthus latirostris. So many spots on the underparts are not feath- 

 ered that, except for the under tail coverts, they are blotched with 

 black and light buff. 



"The most interesting peculiarity consists in a prominent white 

 postocular streak. This is represented by a narrow streak, half the 

 length, in the adult female and juvenile male of first winter plumage, 

 which is reduced to dot or is obsolete in the adult male. This streak 

 consists of nonpennaceous feathers, very loose in texture, as in the 

 juvenile male, and contrasts with the typical feathers of the adult 

 female. 



"Five representatives of juvenile males in their first winter plum- 

 age form part of the Moore collection. They resemble the female 



