266 BULLETIN 16 7, UNITED STATES NATIONAL MUSEUM 



less than 70 feet from the ground, and contained three fresh eggs, the only 

 set I found which contained this number. The nest, not a very substantial 

 affair, consisted of a shallow platform, composed principally of small cotton- 

 wood twigs, a number of which were green and had been broken by the birds 

 themselves. I have seen them do this, selecting a suitable twig, then flying 

 at it very swiftly, grasping it with their talons, and usually succeeding in 

 breaking it off at the first trial. * * * 



The nests are rather frail structures, and were all apparently newly built. 

 They were shallow and but slightly hollowed, not more than V/2 inches deep. 

 The last two found were very difficult to get at, resting as they did on very 

 slender limbs, and from the fact that they were composed principally of green 

 twigs it was no easy matter to detect them. 



Eggs. — The Mexican goshawk lays two or three eggs. All the 

 three sets we collected were of three eggs, but Bendire (1892) 

 says that only "about one set in four contains three eggs" ; and most 

 of the sets in collections seem to consist of two. Most of the eggs 

 are oval in shape, but some are ovate or elongate-ovate. The shell is 

 quite smooth but not glossy. The color is white or very pale bluish 

 white; and they are almost always unmarked, though usually more 

 or less nest stained. Bendire (1892) mentions two eggs "marked 

 with a few buffy brown spots" about the larger ends, and another in 

 which the spots were "scarcely perceptible to the naked eye." The 

 measurements of 50 eggs average 50.8 by 41 millimeters; the eggs 

 showing the four extremes measure 56 by 41.2, 51 by 43.5, 47.3 by 

 39.4, and 49 by 38.2 millimeters. 



Young. — Otho C. Poling watched a female of this species bringing 

 food to her young, and sent the following notes to ]\Iajor Bendire 

 (1892) : 



She made half a dozen or more trips daily to the nest, and whenever she 

 arrived her presence was at once hailed by the hungry nestlings. I watched 

 her closely ; she would make daily trips to the mesquite plains for cotton tails 

 (Lei)us arizonac), some 6 or 8 miles out in the valley. After the first week a 

 neighbor came to my camp and during my absence shot the female, and pre- 

 sented it to me on my return. 



Up to this time I had not seen the male, or at least had seen only one indi- 

 vidual at a time, but noticed on the following day that another bird, evidently 

 the male, appeared and carried on the feeding of the family as regularly as if 

 nothing had happened. The young were now growing rapidly, and their cries 

 wei'e much louder while being fed. One day, on glancing up at the nest, I 

 saw one of them perched upon a limb beside it. The parent bird was near 

 by with some game, and seemed to be urging the young one to fly to it, if it 

 would have its meal. Although it demanded its regular allowance loudly, 1 

 observed it was left out of reach by the old bird until its first lesson of flying 

 was learned. The young were three in number, and all were out of the nest 

 the following day, but returned to it at night. They remained about for 

 several days and finally disappeared. 



Plumages. — I have not seen the downy 3''oung or any nestlings of 

 the Mexican goshawk. In the fully grown juvenal the entire upper 

 parts are "fuscous", the feathers of the head and neck showing con- 



