OLIVACEOUS FLYCATCHER 139 



much worn plumage; and October adults all seem to be in fresh 

 plumage. I have seen adults in full molt as early as August 9, and 

 others molting wings and tails as late as September 20; evidently 

 the complete annual molt occurs in August and September. 



Food. — Very little has been recorded on the food of this flycatcher, 

 but Cottam and Knappen (1939) have reported on the contents of 

 three stomachs taken in Arizona in June and July. "The evidence 

 seems to indicate that any moving insect of small size is acceptable, 

 one bird having ingested some twenty kinds of insects." The list 

 includes a grasshopper, termites, an ant-lion, mayflies, troehoppers, 

 miscellaneous bugs, including assassin bugs, leaf hoppers, spittle bugs, 

 a squash bug, beetles, including wood-borers and weevils, snipe flies 

 and other Diptera, moths, bees and wasps, and spiders. Diptera 

 formed the principal item in each stomach, amounting to 30.66 per- 

 cent of the total food ; Lepidoptera came next, 16 percent (eight indi- 

 viduals, seven adults, and one larva comprised 27 percent of one 

 meal) ; treehoppers made up 14 percent; and bees and wasps figured 

 9 percent. 



We found the olivaceous flycatcher fairly common in the upper 

 parts of the canyons in the Huachuca and Chiricahua Mountains, 

 but it is such a shy, retiring species, oftener heard than seen, that 

 we learned practically nothing about its habits. Nothing of conse- 

 quence seems to have been published about its behavior. Mr. 

 Swarth (1904) says: "They begin to leave [the Huachuca Mountains] 

 as soon as the young have attained their growth, being about the 

 first of the summer residents to move south. Their numbers decrease 

 rapidly after the end of July, and by the middle of August there 

 were practically none left in the mountains. I saw no more, and 

 supposed that they had all left, until September 3, when I came 

 onto a pair of the birds feeding several young. This was right at 

 a place where Mr. Howard had secured a set of eggs earlier in the 

 season, and I have no doubt that, as neither of the parent birds were 

 shot, they reared another brood and were correspondingly delayed 

 in leaving." 



DISTRIBUTION 



Range. — Southern Arizona and western Mexico. 



The olivaceous flycatcher is found north to southern Arizona 

 (Santa Rita Mountains, Tucson, Santa Catalina Mountains, and 

 Paradise); and northwestern Chihuahua (Cajon Bonita). From 

 this region it ranges south through Sonora (Saric, Guaymas, and 

 Agiabampo) ; western Durango (Rio Sestin) ; and Sinaloa (Escui- 

 napa) ; to Guerrero (Coyuca and Acapulco). Over most of this 

 range it is resident but it apparently withdraws from Arizona during 



