22* THE RAPTORIAL BIRDS OF IOWA 



Range. Northern part of the Northern Hemisphere. In North 

 America coming south in winter to Northern United States, and 

 straggling south occasionally to the Bermuda Islands, North Caro- 

 lina, Louisiana, Texas and California. 



I am inclined to believe that the Snowy Owl visits Iowa every 

 winter, but that some years find it here in far greater numbers than 

 do others. The continuously cold winters, especially farther north, 

 favor their southward movements, and though reported almost every 

 year, they seem fewer when the winter is mild. 



These beautiful owls vary greatly in the amount of dusky markings 

 present on the otherwise immaculate feathers. Female birds are less 

 white than males ; and so far as has been observed, very light male 

 birds are rarely taken in the state. 



R. M. Anderson mentions a pure white specimen, now in the State 

 University Museum, taken at Aurelia, January 18, 1885, and a nearly 

 white one which he mounted February 18, 1895, secured at Buffalo 

 Center. 



In conversation with those who have seen Snowy Owls in Iowa, I 

 learn that they not infrequently sit on the tops of hay or straw stacks 

 in the open field during the day-time watching for their prey; and 

 that in the timber they are difficult to discover, especially when the 

 wet snow is clinging to the trunks and larger branches of the trees. 

 The bright sunlight seems .to be no serious hindrance to their hunt- 

 ing. Several writers speak of their celerity on the wing, striking 

 down their quarry with swiftness and skill. 



In the North the Hare and Ptarmigan comprise their chief food, 

 Lemmings, Ducks and occasionally fish being also taken. In Iowa 

 small mammals form the major part of the food, Rabbits and Mice 

 predominating. 



The breeding range in America is north of latitude 53. The num- 

 ber of eggs in a set is said to vary from five to ten. They are depos- 

 ited at intervals, so that when the last bird breaks the shell the oldest 

 one is nearly ready to fly. (Fisher.) By this provision of nature 

 the birds first hatched assist in maintaining an incubation tempera- 

 ture for the benefit of the later arrivals. 



