ARIZONA SULPHUR-BELLIED FLYCATCHER 103 



Mr. Swarth (1904) says: "The concealed yellow crest of the old 

 bird is lacking, the feathers of the crown merely having their bases 

 pale saffron, not sharply defined and hardly apparent at a casual 

 glance; and in the very young birds even this feature is almost 

 entirely absent. Also, the dark median stripe of the rectrices is 

 more narrow than in the adult." 



The yellow crown patch is hardly noticeable in some of the young 

 birds that I have examined, the yellow of the under parts is paler 

 than in the adult, and in very young birds the whole plumage is 

 softer and more blended and the bill is smaller. 



I have not seen enough fall and winter specimens to come to any 

 definite conclusion as to subsequent molts and plumages, but the 

 following remarks by Dickey and van Rossem (1938) indicate that, 

 even in El Salvador, these flycatchers leave for the south before the 

 postjuvenal or the postnuptial molt of adults is complete : "A 

 juvenile and an adult taken, respectively, July 28 and 30, have just 

 started the body molt. In two adults taken August 15 and 16 the 

 body molt is virtually complete, but curiously enough neither in 

 these, nor for that matter in any of the six molting specimens, have 

 any of the old, worn remiges or rectrices been replaced. It seems 

 likely that Myiodynastes, like certain other migratory flycatchers, 

 * * * has a midwinter wing and tail molt which occurs months 

 after the new, fall, body plumage has been acquired." 



I have seen a young male, collected in Panama on November 20, 

 that was molting its tail feathers. 



Food. — Very little has been published on the food of the sulphur- 

 bellied flycatcher. Of two stomachs examined by Mr. van Rossem 

 (Dickey and van Rossem, 1938), one contained insects exclusively, 

 and one moths and small berries. He says that "many birds are 

 stained with the purple juice of an undetermined fruit or berry." 

 Mr. Skutch says in his notes: "The sulphur-bellied flycatcher sub- 

 sists upon insects, which it snatches from the air in the spectacular 

 fashion characteristic of it family, and small fruits and berries of 

 various kinds." 



Behavior. — Mr. Swarth (1904) writes: 



This si)ecies, though a handsome, strikingly marked bird, and at times an 

 exceedingly noisy one, is yet so shy and retiring, that, far from being con- 

 spicuous, a person unfamiliar with the habits of the species might collect for 

 weeks in a region in which it abounded and not know that there were any 

 around. Frequenting as they do, the tops of the tallest trees along the can- 

 yons, which are thickly covered with foliage at the time these birds arrive, a 

 far brighter colored bird might easily escape observation; and their colors, 

 I hough striking, blend exceedingly well with the surrounding vegetation, they 

 are by no means easy to see; the more so that they frequently sit perfectly 

 motionless for a considerable length of time. It has happened more than once, 



