350 



BIED8 OF ILLINOIS. 



B. Size email (wing 3. 60 or less) ; sides of rump without conspicuous cottony tuft. 



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

 most meeting across the breast; throat aud abdomen whitish. Wing. 3.3tt-3.40; 

 tall. 2.80-3.00. 

 8. C. richardsonii. Colors of C. virenst, 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 FLYCATCHER 



Tyrannus horealis Sw. F.'B.-A. ii. 1S31, 141, pi. 35. 

 Contopus borenlis Baibd. B. N. Am. 1858. 188; Cat. N. Am. B. 1850. No. 137.— CoUES, 

 Key.1872. 173: Check List. 1ST4. No. 253; 2d ed. 1882.No. 380; B. N. W. 1874.243.— B. B. & 

 K. Hist. N. Am. B. ii. 1874.353, pi. 44. fig. 1.— RroGW. Nom. N. Am. B. 1881. No. 318. 

 Muscicapa inornala "CooP. iSiNuTT.." NUTT. Man. i. 1832.285. 



Muscicapa cooperi^viT. Man. i, 1832. 282.— Aud. Orn. Biog. ii. 1834, 422; pi. 174; Synop. 

 1839. 41; B. Am. i, 1840. 212. pi. 58. 

 Tyrannus cooperi Bp. 1838.— Nutt. Man. 2d ed. 1, 1840.298. 



Hab. Whole of temperate North America, but colder regions only in summer, breed- 

 ing from northern border of the United States northward, farther south on higher moun- 

 tain ranges, especially westward; also breeding in more elevated districts of Mexico, 

 and migrating south as far as Teragua. 



"Sp. Chab. Wings long, much pointed; the second quill 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 ease 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, leavinga darker central streak. The chin, throat, 

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

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

 streaked with 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 the edges of the 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, 7. 50; wing, 4.33; tail, 3.30; tarsus..60." 

 (.Hist. N. Am. B.) 



The Olive-sided Flycatcher is confined almost exclusively to the 

 northern coniferous forests, including their southern extension along 

 the higher mountain ranges, the principal of which 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." 



