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GE0THLYP1S TBICHAS. 
HABITS. 
A careful observer of birds can readily determine each species of the Warblers, even when 
they are at a distance, by their motions. Some are full of nervous activity, while others are more 
deliberate in their movements. A few closely resemble one another in their evolutions when 
among the trees, but no one who has ever studied their habits will fail to recognize the Blue 
Yellow-backs at a glance ; for none of the Sylvicolidse conduct themselves so peculiarly. They 
sometimes glide along the limbs like Creepers or cling to the under surface of the bark after the 
manner of Nuthatches ; but the next instant finds them skipping nimbly from bough to bough, 
until they perch on the topmost twig, from which they dart into air to secure some rapidly 
moving insect. Thus they are ever changing position and there are but few species which so 
constantly assume so many varying and graceful attitudes. 
These birds are found in Florida throughout the winter but most abundantly in spring, when 
the great avian waves sweep northward. While in the state they frequent the hummocks but more 
generally avoid the piny woods. They arrive in Massachusetts during the latter part of May, when 
they are found among apple trees and in deciduous woods. A few remain in Southern New 
England to breed, but the majority spend the summer in the more northern sections, where 
they build their pensile nests amid the long, gray moss, which so plentifully drapes the trees in 
these wilds. The song of the Blue Yellow-backed Warbler consists of a few simple, lisping 
notes, yet they are given with energy and an accent so peculiar as to distinguish them at once 
from those of all other Warblers. The males continue to sing until August, after which 
various families, composed of parents and young, congregate in small flocks; then, in early 
September, join the other little birds in their southern migrations. 
GENUS Y. GEOTHLYPIS. THE GROUND WARBLERS. 
Gen. Ch. Bill, shorter than the head and rather stout. Wings, short. Feet, large. Tarsus, longer than the hind 
toe and claw. Coracoid bones, slightly exceeding in length the top of the keel, which is low, not being higher than one-half 
the width of sternum. Marginal indentations quite deep. 
The sternum of this genus at once distinguishes it from all other members of the Sylvicolidce, inasmuch as it 
is produced forward in a degree quite remarkable; the coracoid bones are longer and proportionately stouter than 
any other member of the family. 
GEOTHLYPIS TRICHAS. 
Maryland Yellow-throat Warbler. 
Geothlypis trichas Cab., Mus. Hein., 1850, 16. 
DESCRIPTION. 
Form, robust. Size, not small. Bill, stout, not acuminate. Tail, long and well rounded. Sternum, stoutly 
built. Tongue, thin, horny, with the edges straight, not acuminate; bifid, the tips fringed with cilia which extend 
along the sides for about one-third of the terminal length, but become shorter near the base. 
Color. Adult male. Above, olivaceous-green, becoming brownish on the top of the head. Wings and tail 
brown, edged with the same color as the back. A broad frontal band, extending over the eye and on the head, black, 
preceded above by a whitish margin. Throat, breast, bend of wing and under tail coverts, bright yellow. 
Abdomen and under wing coverts paler. Sides and flanks olivaceous. There is no change of plumage in autumn 
excepting that the bill, which in spring is entirely dark brown, then becomes lighter on the lower mandible. 
Young male differs in being duller and lacking the whitish margin to the black mask, which is almost entirely 
obscured by a rufous suffusion on the forehead and is washed with whitish on the side of the head. 
Adult female is without the black mask and with the yellowish beneath quite dull. 
The young female has a suffusion of rufous on' the sides .of the head, and the colors are very dull and undecided. 
