Adults have a complete postnuptial molt in July and August. Ridgway (1902) describes the fall and winter male plumage as "similar to the spring and summer plumage, but all the black areas much broken or obscured; that of the pileum and hindneck by broad olive-green margins to the feathers, the black forming mesial or central streaks, that of the auricular patch overlaid by olive-green tips to the feathers, and that of the throat replaced by nearly uniform lemon yellow, with black appearing as spots or blotches on sides of chest; black streaks on back, etc., more or less concealed." The adult female fall plumage is "similar to the spring and summer plumage, but upper parts slightly browner olive-green, with the streaks obsolete, or nearly so; sides and flanks tinged with brownish." Although considerable wearing away of the concealing tips of the feathers occurs during the winter, thus brightening the nuptial plumage, there is evidently at least a partial prenuptial molt, especially about the head and throat, at which the clear black throat of the male is assumed and perhaps more of the body plumage renewed. Stanley G. Jewett (1944) describes four specimens of adult males that are clearly hybrids between this species and the hermit warbler. _Food._--Professor Beal (1907) examined the contents of 31 stomachs of Townsend's warblers taken in California from October through January, of which he says: "The animal food consists of insects and a few spiders, and amounts to over 95 percent of the food during the time specified. Of this, bugs make up 42 percent, mostly stink-bugs (Pentatomidae) and a few leaf-hoppers and scales." Several stomachs were entirely filled with stink-bugs. Hymenoptera, consisting of both wasps and ants, are eaten to the extent of 25 percent of the food. Most of them are winged species. Perhaps the most striking point in the food of this bird is the great number of weevils or snout-beetles represented. They amount to over 20 percent of the food, while all other beetles form less than 1 percent. The greater number of these insects were of the species _Diodyrhynchus byturoides_, a weevil which destroys the staminate blossoms of coniferous trees. Five stomachs contained, respectively, 68, 65, 53, 50, and 35 of these beetles, or 271 in all. * * * Representatives also of another family of snout-beetles very destructive to timber were present in a few stomachs. These were the engravers (Scolytidae), which lay their eggs beneath the bark of trees, where they hatch, and the larvae bore in every direction. Caterpillars and a few miscellaneous insects and some spiders make up the remainder of the animal food. The less than 5 percent of vegetable food "consists of a few seeds and leaf galls." Gordon W. Gullion tells me that in Eugene, Oreg., from early January until the first of April 1948, Townsend's warblers were observed at a feeding station almost daily, eating cheese, marshmallows, and peanut butter.