286 BULLETIN 203, UNITED STATES NATIONAL MUSEUM 



Adults have a complete postnuptial molt in July and August. 

 Ridgway (1902) describes the fall and winter male plumage as "simi- 

 lar 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 plum- 

 age, 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 stom- 

 achs 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." Sev- 

 eral 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 strilfing 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 Diodj/r^iynchus tyturoides, 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 Janu- 

 ary until the first of April 1948, Townsend's warblers were observed 

 at a feeding station almost daily, eating cheese, marshmallows, and 

 peanut butter. 



