tyrannid.e—tyranninjE: tyrant flycatchers. 



511 



web near end. Tail of 12 rectrices, usually nearly even, sometimes deeply forfieate. Feet 

 small, weak, exclusively fitted for perching ; tarsus little if any longer than middle toe and 

 claw ; anterior toes, especially the outer, extensively coherent at base. Bill very broad and 

 more or loss depressed at base, tapering to a fiue point, thus presenting a more or less perfectly 

 triangular outline when viewed from above ; tip abruptly deflected and usually plainly notched 

 just behind the bend ; culmeu smooth and rounded transversely, straight or nearly so length- 

 wise, except toward end ; commissure straight (or slightly curved) except at end ; gonys long, 

 Hat, not keeled. Nostrils small, circular, strictly basal, overhung but not concealed by bristles. 

 Mouth capacious, its roof somewhat excavated ; rictus ample and deeply cleft ; commissural 

 point almost beneath anterior border of eye. Rictus beset with a number of long stiff vibrissfe, 

 sometimes reaching nearly to end of bill ; generally shorter, and flaring outward on each side ; 

 other bristles or bristle-tipped feathers about base of bill. Bill very light, giving a resonant 

 sound in dried specimens when tapped. On being broken open, the upper mandible will be 

 found extensively hollovr. These several jjeculiarities of the bill (to most of which Omithion 

 offers signal exception) are the most obvious features of the group ; and should prevent our 

 small olivaceous Flycatchers from being confounded even by the tyro with insectivorous Oscines, 

 as Warblers and Vireos. (See Figs. 342, 344.) 



The structure of the bill is admirably adapted for the capture of winged insects; broad 

 and deeply fissured mandibles f(jrm a capacious mouth, wliile long 'Dristles are of service in 

 entangling the creatures in a trap and re- 

 straining their struggles to escape. The 

 shape of the wings and tail confers the power 

 of rapid and varied aerial evolutions neces- 

 sary for successful pursuit of active flying in- 

 sects. A little practice in field ornithology 

 will enable one to recognize Flycatchers from 

 their habit of perching in wait for their prey 

 upon some prominent outpost, in a peculiar 

 attitude, with wings and tail drooped and 

 vibrating in readiness for instant action ; and 

 of dashing into the air, seizing the passing 

 insect with a quick movement and a click of 

 the bill, and then returning to their stand. 

 Although certain Oscines have somewhat the 

 same habit, these pursue insects from place 

 to place, instead of perching in wait at a par- 

 ticular spot, and their forays are not made 

 with such admirable elan. Dependent en- 

 tirely upon insect food. Flycatchers are neces- 

 sarily migratory in our latitudes ; they a{)pear 

 with great res^ularitv in spring, and depart „ „,. „ .,..,,,. ,, . 



'^ ^ •' If I p,Q 344. — Generic det.ails of J;/iar>)nnir. a. Mij^r- 



on tlie approach of cold weather in fall. They archus; b. Sayornix; c. Contopus; d. Empidowix ; all uat. 



arc distributed over temperate North Amer- «'^e. (Ad. nat. del. E. C.) 



ica; many are common birds of tlie Ivistern States. The voice, susceptible of little modula- 

 tion, is usually harsh and strident, though some species have no unmusical whistle or twitter. 

 The sexes are not ordinarily distinguishable (remarkable exception in Pyrocepludus), and 

 dianges of plumage with age and season are not ordinarily great. The modes of nesting are 

 too various to be collectively noted. The larger kinds of Flycatchers are unmistakalde, but 

 several of the smaller species, of the genera Sayornis, Contopus, and especially Emjndonax, 

 look much alike, and their discrimination becomes a matter of much tact and diligence. 



