DUCK HAWK 295 



Occurrence. — Eesident on Negit Island, Mono Lake, where observed May 27, 1916. 

 Lives about rocky cliffs in vicinity of bodies of water inhabited plentifully by water 

 birds. 



The Duck Hawk is the largest and by far the darkest colored of the 

 four falcons in the Yosemite region. Its bodily proportions are similar 

 to those of the Sparrow Hawk, but it is a bird of audacious appearance 

 and behavior, gaining its livelihood by preying almost exclusively on other 

 birds, particularly those which live on or near the water. 



Our only first-hand experience with the Duck Hawk was at Negit 

 Island, Mono Lake, where, at the time of his visit on May 27, 1916, Mr. 

 Dixon found a pair living. Concerning these his notebook reads : 



Soon after landing on the island a shot roused a male Duck Hawk, and he circled 

 over our party, ki-yi-ing loudly, but being careful to keep out of gunshot range. When 

 we arrived at the top of the crater, after a tiresome climb over the loose talus-strewn 

 slope, the female flushed from a nearby boulder and joined the male in his noisy 

 circling. Both of them left the island before we did. We searched for a nest but 

 were unable to find one, although it seemed certain that the hawks must be nesting in 

 one of the numerous pot-holes in the black volcanic rock. 



The skeletons of many Eared Grebes, a species common at most seasons 

 on Mono Lake, were found about the hawks' vantage points, clear evidence 

 of the havoc the hawks had wrought among the water birds that visit the 

 lake. 



On the floor of Yosemite Valley close to Rocky Point, on November 15, 

 1915, a single feather was picked up at the roadside. A comparative study 

 of this feather subsequently, in the Museum, showed that it was one of 

 the secondary flight feathers from the right wing of an adult male Duck 

 Hawk. The features by which it was distinguished from the correspond- 

 ing feathers of other hawks are the following: actual size, outline, curva- 

 ture of whole feather, tone of color of outer web (with slaty gray 'bloom') 

 and pattern of barring on inner portion of inner web. We can only 

 surmise that this feather had been lost through molt or accident by a 

 bird casually visiting or flying over the Yosemite. 



Northern Pigeon Hawk. Falco cclumbarius columbarius Linnaeus 



Field characters. — Somewhat larger than Sparrow Hawk, but of similar build, with 

 narrow wings and long tail. Upper surface blackish brown (immatures) or dark bluish 

 gray (adults); under surface buff, streaked with dark brown; chin buffy white; tail 

 obscurely barred, dark brown and whitish. 



Occurrence. — Winter visitant in small numbers in western part of Yosemite region. 

 Eecorded in several different years at Smith Creek, 6 miles east of Coulterville, by 

 Donald D. McLean. 



