188 
EMP1D0NAX AC AD ICVS. 
EMPIDONAX ACADICUS. 
Acadian Flycatcher. 
Empidonax Acadicus Baird, Birds N. A.; 1858, 197. 
DESCRIPTION. 
Plate X. Adult in spring with the nest and eggs. 
Sp. Ch. Form, rather robust. Size, large. Sternum, stout. Tongue, thin and flat but not horny, bifid at tip but 
not provided with terminal cilia. Bill, broad. Stomach, somewhat muscular, walls ‘10 thick. Lai’ynx, provided with a 
thick and strong sterno-trachealis. Bronchialis, quite well developed, but there is only a small remnant of either division 
of the broncho-trachealis. 
Color. Adult. Above, including upper tail coverts, olivaceous with a decidedly greenish tinge predominating, dark¬ 
est on the head, where the feathers show dusky centers. Wings and tail, brown, with the outer edges of the feathers of 
the latter, greenish, and outer webs, lighter. Outer edges of primaries, also greenish. Tips, edges of the terminal two 
thirds of the secondaries, outer edges and tips of the tertiaries, tips of two rows of wing coverts, forming bars, yellowish- 
white, with the upper bar inclined to be of a deeper yellow. Beneath, white, with the sides, flanks, under wing and tail 
coverts, greenish-yellow. There is a greenish-yellow ring around the eye but the lores are olivaceous. Bill, brown, yellow 
on lower mandible. Feet, brown. 
Young of the year in autumn. Somewhat darker above than in the adult stage, but the greenish markings below are 
more restricted and the yellow of the wings is darker or replaced by yellowish-rufous. 
Nestlings. Very light beneath, showing but little of the greensh markings. More olivaceous above than in the pre¬ 
ceding stage and having indistinct transverse bars of dusky. 
OBSERVATIONS. 
Specimens of the same age and season do not vary much; the wing bars are occasionally darker than the type but oth¬ 
erwise the plumage is similar. The bills are also singularly uniform in size and color for Flycatchers. Known from other 
members of the genus by the larger size, broader bill, decidedly greener color above, and lighter tints beneath, but more, 
particularly by the proportionately shorter fourth primary which causes quite a gap in the otherwise regular graduation of 
the ends of the quills when seen from above. Distributed in summer throughout Eastern United States south of latitude 
42°, exclusive of New England and Florida. Winters in the West Indies. 
DIMENSIONS. 
Average measurements of eleven specimens from Pennsylvania. Length, 5 - 75; stretch, 8*05; wing, 3’00; tail, 2‘25; 
bill, '50; tarsus, *55. Longest specimen, 5‘90; greatest extent of wing, 9*00; longest wing, 3'10; tail, 2 - 40; bill, *55; tarsus, 
•60. Shortest specimen, 5'60; smallest extent of wing, 8'90; shortest wing, 2'80; tail, 2 - 15; bill, *45; tarsus, ’50. 
DESCRIPTION OF NESTS AND EGGS. 
Nests, placed in trees and bushes, composed of sticks, moss, and dried blossoms of beach trees, lined with moss. Di¬ 
mensions, external diameter, 3'00, internal, 2'00. External depth, 1'50, internal, '75. 
Eggs, three to four in number, oval in form, creamy-white in color, spotted and blotched irregularly with reddish- 
brown. Dimensions from ’75 x '50 to ‘78 x - 55. 
HABITS. 
In the spring of 1872, I went to Williamsport, Pennsylvania, in order to study the 
habits of some birds that I had never before had the opportunity of seeing alive and through 
the kindness of my friend, Mr. August Koch, whose hospitality I enjoyed for several weeks, 
I soon became familiar with the best collecting grounds in the vicinity, for Mr. Koch proved 
a most excellent guide as he had always lived in the place and had scoured the country 
diligently every season from childhood in search of its avian treasures. Therefore his 
assistance proved invaluable to me as without it I should have been long in discovering 
some of the most delightful spots that I ever beheld. 
The country about Williamsport is very conducive to bird life as it presents features 
which prove quite attractive to nearly all species. The Susquehanna River flows through 
