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 THE. CO.TB.R Volume XVIII November-December, 1916 Number SOME RESULTS OF A WINTER'S OBSERVATIONS IN ARIZONA By A. BRAZIER HOWELL HE SECTION of country contiguous to old Fort Lowell, a few miles east of Tucson, Arizona, is one of peculiar interest to ornithologists, for here much pioneer work was accomplished by certain of the "old guard," such as Major Bendire, and, at a later date, by several of our contemporaries. But little has been done in this region during the winter months, however, and partly for this reason I spent the time from December 7, 1915, until March 25, follow- ing, some twelve miles east of Tucson, encamped at an altitude of 2500 feet on Rillito Creek, which flows (occasionally) down an arid valley in a pocket between the Rincon and Santa Catalina mountains. In view of the previous extensive collecting carried on hereabout it is hardly worth while to give an annotated list of the birds encountered by myself, but a few notes concerning.certain species may prove of interest. Due to the situation of our camp, and to the fact that I was unable to absent myself over night, my work was confined to the Lower Sonoran zone. In spite of the fact that I walked as far as seven miles up the canyons from their mouths, at no time was I above the sahuaro association. The heigh of this zone here, at least 3700 feet, on the sides of the canyons, and higher on the ridges, is caused both by the southern exposure and by the high base level. It was only at the highest point reached that I caught glimpses of such birds as jays and spotted towhees. Several forms which are not at all uncommon about Tucson seemed to be entirely lacking from our vicinity, notwithstanding the fact that the former place can be only a few feet, possibly seventy-five, lower than the latter, and very similar in character. Yellow-headed Blackbirds (Xanthocephalus xantho- cephalus) were seen about town, but not where we were. Similarly with Whirc- hecked Ravens (Corvus cryptoleucus), although I did note several large flocks wheeling in seemingly aimless circles far above camp, for hours at a time, which evolutions I judged to be some form of early courtship. In the nearby mesquite