Breeding of Harlan's Hawk in Iowa 



By Charles R. Keyes 



A SERIES of five sets of eggs of Harlan's Hawk (Bu/eo borealis har!ani) y 

 collected by the late Jasper Brown, is probably unique and is here- 

 with put on record. The eggs are all of the same general size and type, 

 were all taken in successive years in the same part of a large tract of tim- 

 ber, and so are in all probability the product of a single pair of birds. 



The locality should be more fully described. The tract of timber 

 mentioned extends for about six miles in length and three miles in width 

 along the bluffs to the north of the Iowa river as it passes through the 

 Northern part of Iowa County. A large part of the tract is owned by the 

 Amana Society, a large communistic settlement of Germans founded more 

 than fifty years ago. We have here probably the explanation of its preser- 

 vation. As a rule the larger trees have been judiciously culled except in 

 the deeper hollows, but a sturdy growth of young black, red, white and 

 burr oaks has sprung up, so that the timber has remained practically con- 

 tinuous. The whole area is wild and rough and, with its maze of similar- 

 looking ridges and hollows, quite bewildering to the novice who once leaves 

 the narrow roadways cut through it. The pair of Harlan's Hawks discover- 

 ed by Mr. Brown used for nesting trees the smaller oaks of the east central 

 part of the timber. On three of the data cards the locality is given as 

 Amana, Iowa, on two as Norway, Iowa. The nest sites were nearer to Am- 

 ana, however and this designation would be preferable for all fiyp. The 

 firstset was collected in 1898 and a set each year thereafter until 1902. As 

 stated the eggs are of the same general tvpe and size. Most of the mark- 

 ings are small, a common size being about two millimeters in the shorter 

 and three or four millimeters in the longer diameter, and these tend to dis- 

 tribute themselves over the entire surface of the es^s. Moreover these 

 longer diameters are generally arranged lengthwise of the eggs, thus produc- 

 ing rather an appearance of being marked longitudinally. The ground 

 color of all the eggs is a dainty white. Fuller data concerning the five sets 

 follow. 



I. Set of eggs, slightly incubated, April 21, 1898. Two eggs are 



