TYBANNID^—TYBANNINjE: TYRANT FLYCATCHERS. 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 cTcatures 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 flying insects. A little practice in field ornithology will 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 elan. 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-billed Pitangus, the streaky, yellow-bellied, rufous-tailed 
Myiodynastes, and the curious little beardless " Ornithium. The II 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, mucli 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 
Tail 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 Tyranninoe, a. Myi- 
archus; b. Sayiornis; c. Contopus; d. Empidonax ; 
all nat. size. (Ad. nat. del. E. C.) 
