704 Field Museum of Natural History — Zoology, Vol. IX. 



Adult female: Similar to the male, but top of head like back, 

 without red crown patch. 



Length, 4.25; wing, 2.20; tail, 1.72; bill,' .28. 



The Ruby-crowned Kinglet occurs as an abundant migrant in 

 Illinois and Wisconsin in spring and fall, the majority of them 

 being with us in April and October. It has a delightful song, much 

 louder than would be expected from such a little bird. It usually 

 begins with a variety of light whistles followed by a short, sweet 

 warble. Most of them are gone by the first of November, although a 

 few remain much later. 



Subfamily POLIOPTILIN^. Gnatcatchers. 



Genus POLIOPTILA Sclater. 



357. Polioptila caerulea (Linn.). 



Blue-gray Gnatcatcher. 



Distr.: Eastern United States, west to Nebraska and north to 

 southern Ontario, Michigan, northern Illinois, and southern Wiscon- 

 sin, breeding from Florida and the Gulf states northward nearly 

 throughout its range; winters in the Gulf states, Florida, the Bahama 

 Islands, Cuba, and the Cayman Islands, and in Middle America to 

 Guatemala. 



Adult male: Upper parts, bluish gray; front of forehead, black; 



a narrow black line extends backward, 

 bordering the forehead to above the 

 eye; wings, dark slaty brown or fus- 

 cous, the secondaries bordered with 

 ^ whitish; tail feathers, black, the two 



outer feathers entirely white except at 

 the bases, the third feather tipped with 

 white ; under parts, white, usually faintly washed with pale plumbeous 

 on breast and sides. 



Adult female: Similar, but grayer above, and without black on head. 

 Length, 4.40; wing, 2 to 2.15; tail, 2.05; bill, .40. 

 The Blue-gray Gnatcatcher is a not uncommon summer resident 

 in Illinois and southern Wisconsin. Butler states on the authority 

 of Mr. Eliot Blackwelder that it breeds in Cook Co., Illinois (Birds 

 of Indiana, 1897, p. 1145). Woodruff on the authority of Mr. B. T. 

 Gault records it as breeding in Addison Woods, DuPage Co., Illinois 

 (Birds Chicago Area, 1907, p. 191). 



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