132 BULLETIN 2 03, UNITED STATES NATIONAL MUSEUM 



trated at the large end. The measurements of 50 eggs average 14.6 

 by 11.4 millimeters; the eggs showing the four extremes measure 

 16.5 by 11.5, 14.6 by 12.0, 13.2 by 11.2, and 13.7 by 10.7 millimeters. 

 (Harris.) 



Young. — The period of incubation seems to be unknown, and I can 

 find no information on the development and care of the young. Evi- 

 dence points to the conclusion that incubation and brooding are per- 

 formed entirely by the female, and that at least two broods are reared 

 in a season. Mr. Swarth (1905) says that "several broods are prob- 

 ably raised, as unfinished nests and incomplete sets were found at the 

 same time that broods of young as large as the adults were seen flying 

 about." 



Plumages. — Ridgway (1902) says that the young in juvenal plum- 

 age are "essentially like adults, but much clearer white beneath; no 

 trace of chestnut on crown ; upper tail-coverts ochraceous-buff instead 

 of chestnut; middle and greater wing-coverts tipped with whitish or 

 pale buffy, producing two rather distinct bars." He might have added 

 that the tertials are edged with cinnamon, and that the primaries and 

 rectrices are edged and tipped with white. 



There is apparently a partial post juvenal molt, some time during 

 the summer, when all the plumage except the flight feathers, remiges, 

 and rectrices, is renewed. Young birds now become very similar to 

 adults, but can be recognized by the juvenal wings and tail until the 

 edgings wear ojff. I can find no evidence of a prenuptial molt in 

 either young or old birds. I have seen adults in complete postnuptial 

 molt in August. Fall birds are tinged with brown above and with 

 pale brownish buff below; the chestnut crown patch is concealed by 

 very broad brownish gray tips. Females are not always distinguish- 

 able from males, but usually the chestnut on the crown and upper tail 

 coverts is paler and more restricted. 



Food. — Nothing definite seems to have been published on the food of 

 Lucy's warbler, but it is evidently largely, if not wholly, insectivorous, 

 as it is often seen foraging in the foliage and flower clusters of the 

 mesquites and in other trees. Dr. W. P. Taylor tells me that he has 

 seen it feeding on the pendant sprays of ocotillo flowers, probably 

 gleaning insects or other materials from the exterior. In late spring 

 when the mesquites, palo verdes, the various cacti, and even the 

 saguaros burst into full bloom, these gorgeous desert plants are a blaze 

 of color and attract myriads of insects. 



Behavior. — Mr. Gilman (1909) says that "shyness about the nest 

 seems to be characteristic of these birds." He was seldom able to flush 

 one from its nest. "In three cases only, did the parent birds show 

 what might be called proper amount of solicitude when the nest was 

 approacht. Some of them seemed rather touchy about their nests. 



