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



Nests in a hollow tree or bank, sometimes in buildings. The eggs 

 are usually six to nine, dull white or yellowish white, and measure 

 about 1.75 X 1.25 inches. 



Family STRIGID^. Horned Owls, Screech 



Owls, etc. 



Genus ASIO Brisson. 



174. Asio wilsonianus (Pall.). 



American Long-eared Owl. 



Distr.: Temperate North America to Mexico; breeds throughout 

 its range. 



Adult. \ Ear tufts, very noticeable, usually an inch or more long; 

 first primary only, notched or emarginate; upper plumage, dark 



brown, finely mottled with gray- 

 ish white; bases of the feathers, 

 tawny; under parts, buff and 

 dull white, streaked with dark 

 brown on the breast; belly and 

 sides, barred with dark brown; 

 facial disk, pale brown, edged 

 with blackish; tail, with numer- 

 ous dark brown bars. 

 Sexes similar. 



Length, about 14.50; wing, 

 11.80; tail, 6. 



This species is a not uncommon summer resident in Illinois and 

 Wisconsin, and breeds in suitable localities in both states. 



It nests in various places, sometimes in a hollow tree or among 

 the branches, at others on rocks or even on the ground. It often uses 

 an old deserted nest of a crow or hawk. The eggs are white, five to 

 seven in number, and measure about 1.55 x 1.35 inches. The breed- 

 ing season lasts from late March until May. There is a set of 5 eggs 

 in the Field Museum collection taken at Grinnell, Iowa, May i, 1893. 



