A 6 Brown, Arizona Bird Notes. [fan' 



Outside of the river bottom there is really but little bird life on 

 the Colorado. The rainfall, sometimes, does not exceed a half 

 inch a year. The valley is densely brushed and heavily wooded 

 along the sloughs and banks, but the dead hills give no sign of 

 vegetable life. From twenty to fifty miles above Yuma is a great 

 basin hedged in by detached volcanic mountains. At one time 

 they were covered with pine timber, but are now baked and bare. 

 The wood has become silicified, is hard as adamant and heavy as 

 iron. I have been told by vaqueros familiar with that country, 

 that an occasional tree can still be seen standing, but it has not 

 been my good fortune to see one although 1 have been five times 

 through the section where they are supposed to be. In the 

 washes, some of which are a mile wide, giant cactus, paloverde, 

 and ironwood make up almost the sum total of vegetation. In 

 May the ironwood {Olneya tesota Gray) was covered by dense 

 masses of purple bloom and presented a delightful contrast to the 

 black and brown of the overshadowing hills. 



Next year I hope to define the western boundary of the Elf Owl 

 on the California side of the Colorado River. 



Red-winged, Yellow-headed and Brewer's Blackbirds, and the 

 Dwarf Cowbird, are the most common of all winter residents in 

 the neighborhood of Yuma, Arizona. Redwings scatter up and 

 down the Colorado and Gila River bottoms and can be found 

 nesting throughout the summer. The Yellowheads and Brewer's 

 go north in the spring and are not again seen till the fall migra- 

 tion has set in. Cowbirds are gregarious the year through. 

 During the summer months, when all respectable birds are paired 

 and nesting, these little black and brown midgets can be seen 

 fifty in a flock, and the work of the pestiferous female is apparent 

 in the nests of nearly all small birds found hereabouts. In the 

 winter they skirmish for food in the town by the hundreds. They 

 are audacious little scamps and are ever ready to take chances 

 with the boldest of blackbirds, and some of the latter will almost 

 suffer themselves to be driven over before they will get out of the 

 way. 



That Cowbirds are a recognized nuisance in evidenced by the 

 determination of their afflicted neighbors to rid themselves of 

 honors thrust upon them. Last summer my attention was called 



