350 



BIRDS OF ILLINOIS. 



B. Size .small (wing "CO or less) ; sides of rump without conspicuous cottony tuft. 



i. C. virens. Above olive-slaty, the head darker; sides olive-grayish, this color al- 

 most meeting across the breast; throat and abdomen whitish. Wing. 3.30-3.40; 

 tail,2.80-3.00. 

 3. C. richardsonii. Colors of C. virens, but breast uniform grayish, and upper parts 

 with less of an olive tinge. Wing, 3.25-3.60; tail, 2.80-3.20. 



Contopus borealis (Swains.) 



OLIVE-SIDED FLYCATCHEK. 



Tyramnts lorealis Sw. F. B.-A. ii, 1S31, HI. pi. 35. 

 Contopns borealis Baikb, B. N. Am. 18D8, 188; Cat. N. Am. B. 1850. No. 137.— CouES, 

 Key. 1872, 173; Check List, 1874, No. S.'B; 2d ed.l8S2,No. 380; B. N. W. 1874,243.— B. B. & 

 K. Hist. N. Am. B. ii, 1874,3.53, pi. 44, flg. 1.— Ridgw. Nora. N. Am. B. 1881, No. 318. 

 Muscicapa inonmta "Coop. &, Nutt.." Nutt. Man. i. 1832,2S5. 



Mvscicapa cooper i'SvT-v. Man. i, 1832, 282.— Aud. Orn. Biog. ii, 1834, 422; pi. 174; Synop. 

 1SS9, 41; B. Am, i. 1S40, 212, pi. 5S. 

 Tyraiuins co^inri Bp. 18.3S.— Nutt. Man. 2.1 ed. 1, 1840,293. 



Hab. Whole of toraporate North .^.merica. but colder regions only in summer, breed- 

 ing from nortliern border of the ITnited States northward, farther south onhigher moun- 

 tain ranges, ospoeially westward: also breeding in more elevated districts of Me.xico, 

 and migrating south as far as Veragna. 



"Sp. Chak. Wings long, much pointed; the second auill longest; the first longer 

 than the third. Tail deeply forked. Tarsi short. The upper parts ashy brown, showing 

 darker 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 with the 

 edges of the feathers tinged with gray, leaving a darker central streak. The chin, throat, 

 narrow line down the middle of the breast and body, abdomen, and lower tail-ooverts 

 white or sometimes with a faint tinge of yellow. The lower tail-coverts somewhat 

 streaked witli brown in the centre. On each .side of the rump, generally concealed by 

 the wings, is an elongated bunch of white silky feathers. The wings and tail very dark 

 brown, the former with thi; edges of the secondaries and tertials edged with dull white. 

 The lower wing-coverts and axillaries grayi.sh 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, 7. 50; wing, 4.33; tail, 3.30; tarsus,.C0." 

 arist. JSf. Am. B.) 



The Olive-sided Flycatcher is confined almost exclusively to the 

 northern coniferous forests, including their southern extension along 

 the higher mountain lauges, the principal of wliich it follows through 

 Mexico and Guatemala. Kegarding its occurrence in Illinois, the 

 only knowledge we have is Mr. Nelson's note {Bull. Essex Inst. VIII. 

 1876, p. 113), to the following effect : 



"Not an uncommon migrant, from May 15th to 25th and the last 

 of September and the first of October. I have taken one specimen as 

 late as June 2d. It may breed." 



