16 BUU^ETIN 17 6, UNITED STATES NATIONAL MUSEUM 



Woodpecker (CampopMlus imperialis), for this splendid woodpecker is rel- 

 atively common in the same neighborhood, and is the only woodpecker which 

 excavates such a large hole. 



Nesting. — Practically all we know about the nesting habits of the 



thick-billed parrot is contained in the report of Col. John E. Thayer 



(1906) on some ten nests of this species examined by Wilmot W. 



Brown, Jr., in 1905, in the mountains near Colonia Pachaco and 



Colonia Garcia, Chihuahua, Mexico. The breeding grounds were 



at altitudes varying from 6,500 to 7,500 feet, and all the nests were 



in the tall pines, characteristic of the region. The parrots occupied 



the old nests of the imperial woodpecker, which had been excavated 



at heights ranging from 50 to 80 feet above ground ; one nest was in 



a living longleaf pine, but all the others were in dead, dry, or rotten 



pines. The entrance to the hole was usually circular and 6 or 7 



inches in diameter; the holes varied in depth from 18 to 24 inches, 



and the inner cavity measured from 8 to 10 inches in diameter. 



No nesting material had been brought in, the eggs having been laid 



on the bare wood dust left by woodpeckers. One nest, found on 



August 20, contained two big young ones and one fresh egg ; another 



found on August 28, held two young ones. All the other nests, found 



between August 11 and 25, contained one or two eggs. Mr. Brown 



wrote to Colonel Thayer (1906) that the first tree he climbed was 



"located on a flat-topped mountain at an altitude of 7,500 feet above 



the sea. * * * The tree was about one hundred feet high and was 



thirty-six inches in diameter at the base and was so dry that the 



bark had all peeled off. It was very difficult to climb, not to mention 



the danger." The nest was 80 feet from the ground. 



Eggs. — I have examined the eggs referred to above, which, with the 

 entire Thayer collection, are now in the Museum of Comparative 

 Zoology, in Cambridge. They vary in shape from ovate to rounded- 

 ovate, are pure white in color, and are decidedly glossy; the shell is 

 hard and tliick. The measurments of 20 eggs average 39.49 by 30.63 

 millimeters; the eggs showing the four extremes measure 42 by 31. 

 39.2 by 32, 37.6 by 30.6, and 38.2 by 29 millimeters. 



Plwmages. — Aside from the alcoholic specimens in the Thayer col- 

 lection, which are unsuitable for description, I have seen no nestlings 

 of this species. The immature bird is similar to the adult, but the 

 red of the forehead is more restricted, and the red is lacking on the 

 bend of the wing and on the lower thighs. Nothing seems to be 

 known about the length of time that the immature plumage is worn, 

 or about subsequent molts and plumages. 



Food.— The birds observed by R. D, Lusk (1900) "were very busily 

 engaged with the pine cones, and investigation of their stomachs 

 showed nothing but a plentiful quantity of very immature pinones 



