168 BULLETIN 16 7, UNITED STATES NATIONAL MUSEUM 



During their short stay they fed ahnost exclusively upon the murres, 

 killing, in the estimation of Mr. Emerson, several dozen a day. In 

 1887 the lighthouse man killed about seventeen of these hawks, and 

 during the month of May, 1885, twenty-eight, mostly of this species, 

 were destroyed." 



Nesting. — After making due allowance for the difference in en- 

 vironments and in available nesting sites, the nesting habits of the 

 western redtail and all its habits are similar to those of its eastern 

 relative. It prefers to place its nest at some lofty situation in the 

 tallest tree it can find, but, as its distribution is governed more by 

 the food supply than by suitable nesting sites, it is often obliged to 

 nest at low elevations or on cliffs. 



I have recorded in my notes only 12 nests, 8 seen in Arizona and 

 4 in California. Of the Arizona nests three were on rocky cliffs, 

 two in abandoned nests of the golden eagle, and one in an old raven's 

 nest. Only one of the eagle's nests was closely examined; this was 

 on the face of a bulging rocky cliff on the steep side of a mountain, 

 75 feet from the bottom of the cliff* and 25 feet from the top, giving 

 a fine outlook over the valley far below. It could be reached only 

 by going over the cliff on a rope. The old nest had been repaired 

 somewhat and lined with strips of yucca and other soft fibers. 1 

 collected two eggs from it. 



Two nests were found in open country as we drove along the 

 roads, one 40 feet up in a cottonwood and one 25 feet up in a 

 mesquite. In the deep canyons of the Catalina Mountains, where 

 the giant cottonwoods and sycamores grow, w^e saw the loftiest nests, 

 approximately 90 and 100 feet above the rocky beds of the streams. 



The lowest nest, and one of the most interesting, was only 10 feet 

 from the ground in a double-headed soapweed yucca, which stood 

 out alone on an open plain ; it was a bulky old nest that had been 

 in use for years and was securelj'^ held between the branches of the 

 yucca. It held two pretty eggs (pi. 49). 



Of the California nests only one was on a cliff; this may have 

 been an old raven's nest, but it had been extensively rebuilt. The 

 other three were in large sycamores, 40, 60, and 70 feet from the 

 ground. All the above 12 nests were in commanding situations where 

 the birds could have a good view of their surroundings. 



In Arizona the western redtail often nests in the giant cactus, or 

 saguara, placing its nest where one or two main branches project from 

 the trunk and bend upward. J. H. Clark (1900) describes four such 

 nests at heights varying from 6 to 30 feet from the ground. He also 

 mentions two nests in palo verdes 10 and 12 feet up. 



An unusually lofty nest is described and fully illustrated by Wil- 

 liam L. Finley (1905) and Herman T. Bohlman. The nest was 120 



