72 IOWA ACADEMY OF SCIENCE Vol. XXV, 1918 



the falls of these same years that the northern states experienced 

 unprecedented invasions of northern birds of prey. In the 

 fall of 1916 the flight of Goshawks extended from the Atlantic 

 coast to California. Dr. G. C. Rich informs me of their occur- 

 rence in the latter locality, and numerous published records 

 for other parts of the country are available. During' this fall 

 (1916) seven records were reported by the writer from Sioux 

 City (op. cit., p. 249). Four records of the Goshawk for the 

 winter of 1917-18 are presented in the present paper, all of 

 which were late in the winter. 



The number of Snowy Owls and Great Horned Owls takea 

 here this winter has been very unusual. It is difficult to relate 

 this movement of the birds to weather conditions. It is pos- 

 sible that the same cause suggested for the Goshawk flight will 

 sei've to account for the owl invasion of this winter. The num- 

 ber of Rough-legged Hawks taken this winter is also noteworthy. 



Among the other records of especial interest we might mention 

 the Horned Grebes, the Holboell's Grebe, the Duck Hawk, the 

 Golden Plover, etc. The occurrence of the Purple Finch and 

 of the Carolina Wren is probably accidental. 



We may also note the absence this winter of the following 

 species : the Crosbills, the Redpolls, the Bohemian Waxwings, 

 and the Red-breasted Nuthatches, all of which were recorded a 

 year ago in numbers. Fewer Golden Eagles were mounted by 

 Mr. Anderson than a year ago. 



Notes are included on certain species which may not be con- 

 sidered winter birds, in the usual sense ; the ground for so doing 

 was briefly given in the writer's paper above cited. 



1. Horned Grebe. Colymhiis auritiis. This species occurred 

 in considerable numbers in the vicinity of Sioux City during 

 the last two weeks of October and early part of November. On 

 October 21, 1917, ]\rr. A. J. Anderson collected four at Badger 

 Lake (]Monona county, Iowa) out of a flock of approximately 

 fifty. Many of them were immature, as were two which he 

 took. The length of the smaller one was 10.50 inches, while 

 another one was 13.75 inches long. The two smaller ones had 

 no niffs at all. but the larger one did have very short raf£h. 

 which were depressed and elevated by the bird when taken. 

 An immature bird, which had been shot at Crystal Lake, in 

 Nebraska, was received for mounting bv Mr. Anderson on 



