The postjuvenal molt begins early in July and is often complete before the end of that month. The first winter plumage is similar to that of the adult female at that season. In this plumage the sexes are not very different, and the crown patch is not much in evidence or is altogether lacking in the young female; both sexes are browner and with less yellow than in the adult plumage, and the female is duller than the male. A partial prenuptial molt occurs between February and May, mainly about the head, during which the chestnut crown patch is at least partially assumed and the young birds become almost indistinguishable from adults. There is, however, considerable individual variation in the advance toward maturity. Subsequent molts consist of a complete postnuptial molt in July and August, and a partial prenuptial molt in early spring. The adult male in the fall is browner above and on the flanks, and the yellow on the chest is duller than in the spring, while the chestnut crown patch is concealed by brownish gray tips. The female, also, is browner than in the spring, with little if any yellow on the chest and with the crown patch similarly concealed. In spring birds there is much individual variation, perhaps owing to age, in the amount of yellow on the breast, throat, and chin. Some females are nearly as brightly colored as are the duller males, some have very little yellow on the chest and some lack the chestnut crown patch. _Food._--Our information on the food of Virginia's warbler is limited to the observation of Bailey and Niedrach (1938) who saw a pair of these warblers feeding their young on the caterpillars that eat the foliage of the trees and shrubs on their nesting grounds. It is significant that after these caterpillars are no longer available the warbler leaves its breeding haunts and moves down into the foothills, perhaps in search of other food; and it would be interesting to learn what that food is. It has been seen foraging on the ground, as well as in the foliage, and flying up into the air to capture insects on the wing. _Behavior._--Virginia's warbler is a shy, retiring species, spending most of its time not far above the ground in the thick underbrush, where it is not easily seen, as its colors match its surroundings. It is also very lively and active, almost constantly in motion, except when it mounts to the top of some dead bush or small tree to sit and sing.