230 LIFE HISTORIES OF NORTH AMERICAN BIRDS. 



Mr. Stephens published subsequently the following account: "May 28, 

 1876, I found a nest of Buteo zonocercus in a very large cottonwood tree, in 

 a grove of the same, in the mouth of a canon of the Gila River, in New 

 Mexico, about 20 miles above the Arizona line. I saw the parent fly from 

 the nest and with its mate circle around overhead. One alighted on the 

 cliff overhanging the grove, which I succeeded in killing. It proved to be 

 the male. I had no climbers and could not then get to the nest, but the next 

 day I returned with a rope and succeeded in getting near enough to work 

 my hand up through the nest and reach one egg, which was all there was. 

 The nest was quite bulky, composed of twigs lined with strips of the inner 

 bark of the cottonwood. 



"The egg was very near hatching, and in attempting to extract the 

 embryo I broke it, and it has since been broken into small pieces. It was 

 marked with large reddish brown blotches, irregularly distributed on a dirty 

 white ground. I still have the male parent." 1 Mr. Stephens sent me the 

 pieces of this egg, which were all small, but as described above. 



The next published account of the nesting habits of the Zone-tailed Hawk, 

 and by far the most complete, is one by Asst. Surg. Edgar A. Mearns, U. S. 

 Army. It is too long to quote fully, and I extract only such portions as are of 

 special interest. 



Dr. Mearns found his first nest of this species while camped in a grove 

 of cottonwood trees upon the banks of New River, Arizona, May 16, 1885. 

 While he was resting in the shade, a shrill whistle drew his attention to a 

 Hawk that came gliding toward him through the dark shadows of the dense 

 foliage. A quick shot brought the bird to his feet. On searching the vicinity 

 he was not long in discovering a bulky nest fixed in the forks of a large 

 cottonwood branch across the stream, at an elevation of about 25 feet, and 

 the female parent standing upon it. She gave a loud whistle and came 

 skimming toward him, and was also shot. The nest was coarsely built of 

 rather large sticks, with considerable concavity, lined with a few cottonwood 

 leaves only, and contained a single egg of a rounded oval shape, slightly 

 smaller at one end, in color clear bluish white, immaculate, and measuring 55 

 by 43 millimetres. On dissecting the female he discovered that two would 

 have been the full complement for this pair. 



The doctor encamped the next day at the Aqua Frio. He says: "Here I 

 again found the Zone-tailed Hawk. A female was shot as she flew screaming 

 at me, and the nest was soon found in a cottonwood tree near by. The male 

 parent sat upon the eggs and flew away when I got close up to the tree and 

 shouted. It disappeared after circling over the canon a few times, and did not 

 return while I was there, although I spent several hours in the vicinity. I 

 climbed with vast exertion to the nest, which was built in a fork about 50 feet 

 from the ground and was exactly like the first one. It was composed of sticks, 



'Bulletin of the Nuttall Ornithological Club, Vol. iv, July, 1879, p. 189. 



