Widmann — A Preliminary Catalog of the Birds of Missouri. 99 



species becomes rare, though the last may be noted a month 

 later (November 11, 1897, Keokuk, Currier). Its return in 

 spring is rather irregular; it is seldom seen in March, oftener in 

 early April, but summer residents cannot be expected back in 

 their breeding haunts with certainty before the latter part of 

 the month. 



347a. Archibuteo lagopus sancti-johannis (Gmel). Ameri- 

 can Rough-legged Hawk. 



Falco sancti-johannis. Falco lagopus. Buteo lagopus. Archibuteo lagopus. 

 Falco nigcr. Buteo niger. Black Hawk. Rough-legged Buzzard. 



Geog. Dist.— From the Gulf of Mexico north to Newfoundland, 

 Ungava and through the Barren Grounds to Alaska; rare from 

 foot of Rocky Mountains westward. Breeds in Newfoundland, 

 Ungava and from northern Assiniboia and Alberta northward, 

 exceptionally south to northern border of United States. Win- 

 ters from northern United States southward, but chiefly in the 

 Middle and Southern States, being influenced largely by the 

 amount of snow which covers the ground, depriving it of its 

 favorite food — the meadow mice — for which it often hunts in 

 the twilight. Like most of our winter visitants the Rough-leg 

 is of irregular occurrence in Missouri, both in numbers and time 

 of arrival and departure. It is never seen before the first of 

 November and hardly ever after the first of April (April 6, 1902, 

 Keokuk, Currier). The bulk comes about the latter part of 

 November arid has left us by the middle of March. In open, 

 moderately cold w^inters the fields, pastures, meadows ancl 

 marshes of northern Missouri are well supplied with this inde- 

 fatigable mouser, which, somewhat resembling a Marsh Hawk, 

 flies low over the ground, every once in a while hovering for a 

 few seconds to subject the ground to a closer examination, or 

 pouncing on its unlucky quarry. 



[348. Archibuteo ferrugineus (Licht.). Ferruginous Rough- 

 leg]. 



Falco ferrugineus. California Squirrel Hawk. 



Geog. Dist. — ^Western North America, east to eastern Da- 

 kotas, eastern Nebraska, middle of Kansas and Texas. North 

 to northern Assiniboia ; south into Mexico. Breeds from Utah, 

 Colorado and Kansas northward; in California in the interior 

 valleys to San Diego Co. 



