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BIRDS OF PENNSYLVANIA. 
Florida, Louisiana and other of the southern states, feeding on “ differ¬ 
ent berries, as well as insects.” 
The stomach contents of thirteen of these birds which I have cap¬ 
tured during the summer time^ in different sections of the state, con¬ 
sisted of flies, small beetles, butterflies, etc. 
Contopus borealis (Swains.). 
Olive-sided Flycatcher. 
Description. 
“Wings long, much pointed ; second quill longest; first longer than third. Tail 
deeply forked. Tarsi short. The upper parts ashy-brown, showing dark-brown 
centres of the feathers ; this is eminently the case on the top of the head ; the sides 
of the head and neck, of the breast and body resembling the back, but the edges of 
the feathers tinged with gray, leaving a darker central streak. The chin, throat, 
narrow line down middle of breast and abdomen, and lower tail-coverts white, or 
sometimes with a faint tinge of yellow. The lower tail-coverts somewhat streaked 
with brown in the center. On each side of rump generally concealed by the wings, 
is an elongated bunch of white silky feathers. The wings and tail very dark-brown, 
the former with the edges of secondaries and tertials edged with dull-white. The 
lower wing-coverts and axillaries grayish-brown. The tips of the primaries and 
tail feathers rather paler. Feet and upper mandible black; lower mandible brown. 
The young of the year similar, but the color duller ; edges of wing feathers dull- 
rusty instead of grayish-white. The feet light brown. Length 1\ ; extent about 13± ; 
wing, 4.33 ; tail, 3.30 ; tarsus .60.”— Hist. N. Am. B. 
Habitat .—North America, breeding from the northern and the higher mountain¬ 
ous parts of the United States northward. In winter, south to Central America, etc. 
The Olive-sided Flycatcher, by far the rarest of all the family found 
in this state, arrives here about the first week in May. Judge Libhart 
states that this species (probably fifteen or twenty years ago) was found 
as a breeder in Lancaster county, where, however, in recent years it has 
been observed by Dr. Treichler and others only as a very rare spring 
and fall migrant. Prof. August Kock says it is seldom seen, but he is 
quite positive that it breeds occasionally in the mountains of Lycoming 
county, and Prof. H. J. Roddy is also of the opinion that it occurs as a 
rare breeder in parts of Perry county. Mr. Geo. B. Sennett, of Erie; H. 
C. Kirkpatrick, of Crawford; Dr. J. W. Detwiller, of Northampton, and 
Dr. W. Yan Fleet, of Clinton, are the only naturalists, other than those 
previously mentioned, whose reports have been sent to me and in which 
reference is made to this bird, and they all record it as a rare migrant 
in the spring and fall. A few specimens of this species have been cap 
tured at irregular intervals, in the spring and fall, in Chester, Delaware 
and Philadelphia counties during the past fifteen years. 
