FORK-TAILED FLYCATCHER 79 



changes, I am following Dr. Jonathan Dwight, Jr. (1900) in liis 

 excellent treatment of this subject. He says that the sexes are alike 

 in the juvenal plumage, which he describes as follows: "Above, in- 

 cluding wings and tail, olive-brown ; coverts and wing-quills nar- 

 rowly edged with pale russet. Below, white. Orbital region dull 

 clove-brown. * * * xhe tips of the primaries are rounded and 

 there is no yellow crown-patch. The tail is but five inches in length." 



A complete postjuvenal molt produces, in September or later, a 

 first winter plumage in which young and old birds become practically 

 indistinguishable. ''Males become glossy black with yellow crown- 

 patch ; the outer pair of rectrices are fully nine inches in length and 

 blacker than those of the juvenal dress; the three distal primaries 

 are deeply incised at the tips, a peculiar emargination." 



There is, apparently, a partial prenuptial molt in both young and 

 old birds in February and March, involving usually the body plumage 

 only. The complete annual molt of adults occurs mainly in August 

 and September, in birds reared north of the Equator. "In later 

 plumages the sexes are very similar, the females usually with less 

 emargination''; and the yellow crown patch is smaller in the female. 



Food. — The fork-tailed flycatcher feeds largely, although not 

 wholly, on insects, mostly obtained on or near the ground. Perched 

 (in some low shrub or stalk, it watches for passing insects and darts 

 out after them in the air. But Mr. Skutch (MS.) also observed that 

 •'most of their prey seemed to be snatched from the grass or the 

 ground; on a burnt hilltop above the village, where the fire had con- 

 sumed the grass but only charred the low bushes, I could see clearly 

 that they picked most of their food from the charred soil, often at 

 a considerable distance from the point where they had been perching, 

 then alighted upon another low perch to devour it." 



He also describes, in his notes made at Balboa on December 30, 

 1930, another method of feeding: "Walking down the magnificent 

 avenue of royal palms that leads to the Administration Building, I 

 saw my first fork-tailed flycatchers this morning. There were doz- 

 ens of them, perching in the trees bordering the parkwa}', and sally- 

 ing out now and again to pluck a red berry from one of the heavy 

 clusters of ripe fruit that hung from the palm trees in the central 

 square. It was a delight to watch them fly lightly and airily for- 

 ward, the two narrow and elongated outer tail feathers, each longer 

 than the body of the bird, forming slender black streamers, which 

 undulated gracefully with every movement. As the bird poised on 

 wing before the brilliant cluster to pluck a berry in its bill, the tail 

 was spread until its posterior margin suggested the crescent moon, 

 with its horns extended into narrow ribbons of black. The berry was 

 usually carried back to a perch in a tree above the sidewalk and there 



