ANIs^A'S HUMMINGBIRD 375 



The second egg never hatched, and after the nest was abandoned the broken 

 shell was found buried in the bottom of the nest. 



Eggs. — [Author's note : The usual two eggs of Anna's humming- 

 bird are indistinguishable from the eggs of other hummingbirds of 

 similar size. The measurements of 50 eggs average 13.31 by 8.65 mil- 

 limeters; the eggs showing the four extremes measure 14.3 by 9.0, 

 12.7 by 9.4, and 11.3 by 7.7 millimeters.] 



Young. — It will be noted from Mr. Anthony's account that the in- 

 cubation period is considerably longer than that of most common 

 passerine birds, despite the smaller size of the eggs. This is con- 

 firmed in the following description by J. H. Bowles (1910) of the 

 nesting of an Anna's hummingbird at Santa Barbara : 



The first egg was laid January 3, but during the following night a heavy 

 frost left ice more than a quarter of an inch in thickness on the puddles. * * * 



I think the icy weather must have been too severe for the first egg, for, 

 whatever the cause, only one egg hatched. This took place on January 22, 

 showing the period of incubation to be just seventeen days. It may be interest- 

 ing to note here that I have found thirteen days to be the period of incubation 

 for eggs of the Black-chinned Hummer {Archilochus alexandri). This great 

 difference I think may be attributed in part to the consistency of the albumen, 

 which in eggs of C. anna is thick and almost gummy, while in A. alexandri it is 

 thin as in eggs of other small birds. 



In spite of the very cold, rainy weather my young hummer grew very rapidly ; 

 but it was not until he was thirteen days old that his eyes opened. * * * 



On February 13, when he was just three weeks old, the young bird left the 

 nest. 



I believe, however, that the difference in incubating time between 

 Anna's hummingbird and other species cannot be so great as assumed 

 by Mr. Bowles, as I have found the period for both black-chinned 

 and Costa's to be about 16 days, while, on the other hand, Donald R. 

 Dickey (1915) gives an even shorter time for Anna's hummingbird, 

 as observed in the Ojai Valley of Ventura County : 



Finally, on the fourteenth day of incubation — a long period for so small a 

 bird — the young hatched into black, grubby caterpillars, with smoky fuzz in 

 two lines down the back, and squat, yellowish mouths that gave no hint of the 

 future awl-like bills. Now the mother's care was redoubled, and on the fifth 

 day their eyes opened. Two days later respectable pin feathers transformed 

 them from loathsome black worms into tiny porcupines. 



Now we saw more and more often the grewsome-seemiug spectacle of their 

 feeding. The female's foraged burden of small insect life, culled from the 

 flowers' corollas, and doubtless nectar-sweetened, is transferred to the young 

 by regurgitation, and to avoid waste the mother's needle bill is driven to its 

 hilt down the hungry youngster's throat. It suggests, as someone has said, 

 a "major surgical operation," but the young so obviously enjoy and thrive upon 

 it that we outsiders slowly lost our fear for them. At last the feathers broke 

 their sheaths and the wee mites took on the semblance of real hummers. And 

 then one night the worst happened — a prowling cat found the nest and exacted 

 nature's price of death ! 



