The relationships of the Tyrannidæ are closest to the Cotingidæ. These last differ mainly in having the tarsus more or less reticulated, or covered in part at least with small angular scales, instead of continuous broad ones; and in the greater adhesion of the toes. The legs are shorter, and the body broader and more depressed. The bill is less abundantly provided with bristles, and the species do not appear to be strictly flycatchers, feeding more on berries and on stationary insects and larvæ, rather than capturing them on the wing. Two species of this family, Hadrostomus affinis[62] and Pachyramphus major,[63] were introduced into the Birds of North America, from specimens collected by Lieutenant Couch in the valley of the Rio
Grande, not far from the border of the United States, but as they have not yet been detected within our limits, we have concluded to omit them in the present work.
The bird fauna of America may be said to have one of its chief features in the great number and variety of its Tyrannidæ, the family being strictly a New World one. Nearly every possible diversity of form is exhibited by different members; the size, however, usually varying from that of our common Robin to that of the Kinglet, our smallest bird with exception of the Humming-Bird. Of the numerous subfamilies, however, only one, the Tyranninæ proper, belongs to North America, and will be readily distinguished from other of our land birds by the family characters given at the head of this article, and which, as drawn up, apply rather to the subfamily than to the Tyrannidæ generally.
The North American species of the Tyranninæ may, for our present purposes, be divided into Tyranni and Tyrannuli. The former are large, generally with bright color, pointed wings, with attenuated primaries and a colored crest in the middle of the crown. The others are plainer, smaller, without colored crest; the primaries not attenuated.
The genera of our Flycatchers may be arranged as follows:—
TYRANNI. Size large; colors generally brilliant; crown with a brightly colored crest, usually concealed; outer primaries abruptly contracted or attenuated near the tip; upper scales of tarsus usually continuing round on the outside and behind. Nest in trees, very bulky, containing much downy material; eggs white or pinkish, with ovate dots of rich brown, of various shades.
Milvulus. Tail excessively forked and lengthened; more than twice as long as the wings.
Tyrannus. Tail moderate; nearly even or slightly forked; less than the wings.
TYRANNULI. Size generally small; colors usually plain; crown without any colored crest concealed by the tips of the feathers; primaries normal; scales of the upper part of the tarsus usually continuing only to the middle of the outer face, and a second series opposite to them behind.
1. Tail lengthened; about equal to the wings, which reach scarcely to its middle.