The Cooper Hawks 



is deemed of sufficient importance to be recorded here. The author ventures, also, 

 to advance the claim that an average difference in the size of eggs is just as important 

 as a diagnostic distinction in the evaluation of subspecies, as is a difference in the 

 length of bill or wing. Indeed, it is to be suspected that certain oological differences 

 are both more profound and more ancient than many superficial marks upon which 

 taxonomists rely. 



Range of .4. c. mexicanus. — Resident in the Southwestern States and in Mexico. 



Distribution in California. — Presumed to be the form occupying the southern 

 portion of the State, perhaps the region south of the Tehachipe, and the valley of the 

 Colorado. Not yet distinguished from A. c. cooperi. 



A DARK SHADOW, as of a bird, flashed across my north study win- 

 dow, and, surmising from the angle of descent that the bird might have 

 alighted in the sharp angle of the fence to westward, I peered suddenly 

 out of the west window. There, upon the ground, sat the bird, a wicked- 

 looking Cooper Hawk, back to, and eyeing me maliciously over his shoul- 

 der. He did not seem to be in any hurry, nor did I think to inquire the 

 nature of his business, for he fairly transfixed me with that gleaming red 

 eye. Presently, observing how much advantage I should have of the 

 bird if I should rush him, I bethought myself of the possibility of bolting 

 out of the north window at him. The bird appeared to divine my thoughts, 

 for he hopped forward — rather awkwardly I considered — and pressed 

 between the palings of the high picket fence which separates my plot 

 from neighbor Hoover's pasture. Here he sat with free wing-room, but 

 awkwardly still. Then seeing the jig was up, anyway, I pounded on the 

 window, whereupon the hawk took heavily to wing. Judge of my as- 

 tonishment, however, when I saw that he was bearing off a large quarry, 

 presumably a Valley Quail! There he had been right before me, back 

 on, to be sure, within 12 feet, and in the very act of setting his talons 

 more deeply into a prostrate victim. Yet so great was the power of that 

 evil eye, I had never guessed the mischief afoot. 



The aperture through which the hawk had forced himself so neatly, 

 together with his unsuspected burden, proved to be exactly two and three- 

 sixteenth inches wide without any lateral give. Efficiency as well as ruth- 

 lessness belongs to the Cooper Hawk. 



Next after the American Kestrel (Cerchneis sparverius sparverius), 

 the Cooper Hawk is the most abundant and the best distributed Hawk in 

 California. This does not necessarily imply that the bird is most in evi- 

 dence, for it is wary and furtive to a degree, insomuch that it is able to 

 maintain itself almost unnoticed in some sections where gun-fire is un- 

 usually vigilant. Where not persecuted, however, it is possessed of a 

 lively curiosity, and will appear unexpectedly at one's elbow, as though 

 desiring to profit by any woodland commotion likely to set the little birds 



1665 



