TYRANNIDJE — TYRANNINJE : TYRA NT FL YCA TGHERS. 



429 



hollow. These several peculiarities of the bill (to most of which Ornithium offers signal ex- 

 ception) 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 the War- 

 blers and Vireos. (See figs. 278, 280.) 



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

 and deeply fissured mandibles form a capacious mouth, while the long bristles are of service in 

 entangling the creatures in a trap and restraining their struggles to escape. The shape of the 

 wings and tail confers the power of rapid and varied aerial evolutions necessary for the successful 

 pursuit of active fiying insects. A little practice in field ornithology wiU enable one to recog- 

 nize the Flycatchers from their habit of perching in wait for their prey upon some prominent 

 outpost, in a peculiar attitude, with the wings and tail drooped and vibrating in readiness for 

 instant action ; and of dashing into the air, 

 seizing the passing insect with a quick move- 

 ment 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 particular spot, and their forays are 

 not made with such admirable dlan. Depend- 

 ent entirely upon insect food, the Flycatchers 

 are necessarily migratory in our latitudes ; they 

 appear with great regularity in spring, and 

 depart on the approach of cold weather in the 

 fall. They are distributed over temperate 

 North America ; many of them are common 

 birds of the Eastern States. The voice, sus- 

 ceptible of little modulation, is usually harsh 

 and strident, though some species have no 

 unmusical whistle or twitter. The sexes are 

 not ordinarily distinguishable (remarkable ex- 

 ception in Pyrocephalus), and the changes 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 unmistakable, but several of 

 the smaller species, of the genera Sayiornis, Contopus, and especially Empidonax, look much 

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



To the 8 genera of Tyrannidce long known to be North American have lately been added 

 3 from Mexico — the immense-biUed Pitangus, the streaky, yellow-bellied, rufous-tailed 

 Myiodynastes, and the curious little " beardless " Ornithium. The 11 may be readily discrimi- 

 nated by the following characters : — 



Analysis of Genera. 

 Bill flattish, fully bristled and hooked as usual in Tyrannidce. 



One or more outer primaries attenuate at end. A flame or yellow spot on crown. ( Tyranni.) 



Tail deeply forficate, much longer than wings Milvulus 118 



Tail simple, not longer than wings Tyrannus 119 



Outer primaries not attenuated. A yellow crown-spot. 



Wings and tail extensively rufous; belly yellow; no streaks except on head .... Pitangus 116 

 Tall but not wings extensively rufous ; belly yellow. Streaked above and below . Myiodynastes 117 

 Outer primaries not attenuate. Tail moderate. No yellow spot on crown. (Tyrannulce.) 



Tail chestnut and dusky, in lengthwise pattern. Belly yellow ; throat ashy .... Myiarchus 120 

 Tail without chestnut. 



Tail about equal to or little shorter than wing, slightly or not forked. Bill narrow. Tarsus 



Fig. 280. — Generic details of Tyrannince, a. Myi- 

 archus; b. Sayiornis; c. Contopus; d. Empidonax; 

 all nat. size. (Ad. nat. del. E. C.) 



