FALCONID.E — Till-: FALCONS. 035 



The average size of tlie eggs of this bird is 1.56 by l.l>4 inches. Tiio 

 color is usually a uniform dull wliito, but is occasionally tinged with as light 

 bluish shade. They are nearly spherical, though not more so than the (!ggs 

 of several species, and are e(|ual at either end. Their surface is slightly 

 granidated. The number of the eggs varies from three to four, though occa- 

 sionally tliere are five in a nest 



Tlie niii.\imum length of the egg of this species is 2.00 inches, the mini- 

 mum l.H .3 ; the maximum breadth 1.00, the minimum 1.50 inclies. In occa- 

 sional instances I have known the eggs of this species more or less distinctly 

 marked, especially about the larger end, with blotches of a light yellowish- 

 brown. Those most distinctly marked in this manner were taken and iden- 

 tified by Mr. Paine. 



A nest of this Hawk, found by Dr. J. W. Velie, was built on a poplar- 

 tree, about forty feet i'rom the ground, and was composed of sticks and lined 

 with moss and leaves. There was a small cleared si)ace of three c»r i'our 

 rods in extent, in the middle of which the tree stood, and about a ([uaiter 

 of a mile from the main channel of the IVIississippi Iiiver, on Kock Island. 



The Cooper Hawk was found on Afount Tom by Mr. William Street, 

 nesting for the most part in pine or hemlock trees, usually choosing one in 

 a thick clump. They begin to lay about the first of May, usually depos- 

 iting four eggs. They are very shy, and it is almost impossible to get 

 within shot of them, even when they have young. They rarely molest the 

 poultry-yard, but seem to live chiefly on small birds and animals. They 

 leave their nest at once whenever it is approached, and will not return until 

 the intruder has gone. 



The var. mcxicanus, originally described by Mr. Swainsnn from Mexican 

 specimens obtained near Real del Monte, has been ascertained to cross our 

 boundaries, and is found in all the territory between the Hocky Mountains 

 and the Pacific, as far north as Washington Teriitory. Dr. Cooper has never 

 met with this Hawk, but supposes its general habits, and esiiecially those 

 regulating its migrations, closely resemble those of A. coopcri, to which the 

 birel itself, in all but size, is so similar. Dr. Coues speaks of it as a common 

 resident species in Arizona. He states that he has seen young birds of tliis 

 species, reared by the hand from the nest, become so thoroughly domesti- 

 cated as to come to their master on being whistled for, and perch on his 

 shoulder, or follow him when shooting small birds for their food. Tliey 

 were allowed their entire liltertv. Their ordinary note was a shrill and 

 harsh scream. A low, plaintive, lisping whistle was indicative of hunger. 



Dr. Suckley, who met with th: bird on Paget Sound, where a specimen 

 was shot on a salt marsh, states that, while soaring <ibout, it resembled in its 

 motions the common Marsh Hawk, or Hen Hanier {Circus hitdsoniiis). 



