40 PROCEEDINGS OF THE ACADEMY OP 



Arizona are sufficiently diverse from those of adjacent Territories to produce 

 any special differences in their Avifaunae; unless indeed the apparent absence 

 of one family* can be substantiated as a marked peculiarity. 



Some facts of physical geography have a marked influence upon the birds. 

 From the dearth of water throughout almost every portion of the Territory 

 tbere results, as a natural consequence, a great paucity of Grallatorial and 

 Natatorial forms ; so much so, that with a few prominent exceptions, a list of 

 the Water Birds of the Territory is little more than an enumeration of those 

 of the Colorado and Gila Rivers. There is also to be noted, as an interesting 

 fact, the effect of the hot, arid, desert wastes of the region of the Gila, and 

 Southern Arizona generally, upon the colors of the species found there. A 

 light, dull, apparently faded condition of plumage, in which some shade of 

 gray is a predominant tint, and all lines and streaks are more or less obsolete 

 in character, is met with in numerous instances, forming true local races or 

 varieties. In other casesj- the specific characters which distinguish birds of 

 this middle southern province from other closely allied species, partake in a 

 measure of this peculiarity. 



Our knowledge of the Ornis of Arizona has been hitherto chiefly obtained 

 from the collections made by the naturalists attached to several of the United 

 states Government Surveys of various regions of the West. The expeditions 

 along the 35th and the 32d parallel passed through different portions of the 

 Territory; the Mexican Boundary Survey along its southern border; that of 

 the Colorado passed up the river to the head of navigation. The first men- 

 tioned of these, under Capt. A. W. Whipple, with Dr. C. B R. Kennedy and Mr. 

 H. B. Mollhausen as naturalists, passed very near the present site of Fort 

 Whipple; and its collections agree most closely with my own. Collections 

 of some private individuals have added materially to the results of these Ex- 

 plorations ; especially those of Dr. J. G. Cooper, who spent several months at 

 Fort Mojave, on the Colorado River, in latitude 35 N. To the observations and 

 collections of this gentleman I shall have frequent occasion to allude ; and I 

 am indebted to him for free access to his MSS. notes, which are of special in- 

 terest and value, not only as adding some species to my list, but as affording 

 an opportunity of comparing the birds of Fort Whipple with those of a point 

 in the Colorado valley, at nearly the same latitude ; whereby the effect of the 

 differences in physical geography is finely elucidated. My own observations, 

 made during the sixteen months I resided in Arizona, extend over the Ter- 

 ritory from east to west, chiefly near the line of the 35th parallel; and along 

 the valley of the Colorado from Fort Mojave to Fort Yuma. It was chiefly 

 at Fort Whipple, and the mountainous region of that vicinity, that my collec- 

 tions were made. This particular locality possesses a rich and varied Avi- 

 fauna ; numerous features of which are quite peculiar, as might be expected 

 from the following facts regarding its situation and relations. 



Fort Whipple is very nearly in latitude 34 30 / N.. longitude 112 W. (from 

 Greenwich.) It is difficult to give an estimate of the altitude of the vicinity 

 with anything more than approximate accuracy, in consequence of the broken 

 and varied nature of the surface. It may be stated, in round numbers, as be- 

 tween 4000 and 5000 feet ; but in several directions, and more particularly 

 to the southward, there are confused masses of short mountain ranges or ab- 

 rupt isolated peaks, which rise far above the level indicated by the preceding 

 figures. The altitude of the San Francisco mountains, about sixty miles a 

 little east of north of Whipple, has been fixed at about 12,000 feet. The main 

 point of interest which attaches to this particular locality Fort Whipple 



* The Telraoiiidie. I have never seen nor heard of a finale species of grouse in Arizona. But 

 the northern portions of the Territory are so imperfectly explored that it is not safe to assert their 

 entire absence. Dr. J. G. Cooper has seen the Centrocercus urophasianus ou the Mojave Kiver; 

 the southernmost point, 1 believe, from which it has thus far been recorded. 



t Of which Ilarparhynchus Ltcontzior criisaiis, as distinguished from H. redivivus of the Pacific 

 coast, is a go.id example. 



fMarch, 



