WESTERN GOSHAWK. Astur atricapillus striatulus Ridgway

Field characters.—Size of Red-tailed Hawk, but of more slender build, with shorter, more rounded wings, and longer, more slender tail (pl. 44b); patch at either side of rump, as seen in flight, white. Upper surface uniform dark slate gray in adults; dark brown in immature birds; under surface white, finely barred with black in adults, and broadly streaked with dark brown in immatures. Voice: A series of loud, insistent, staccato cries, kak, kak, kak, with a ringing quality, sometimes varied to kee-är.

Occurrence.—Resident in small numbers in Canadian Zone on west slope of Sierra Nevada. Visits Yosemite Valley in winter. Lives in or about thick forests.

The Western Goshawk is the largest of the three bullet hawks, which make birds their principal victims. Its large size enables it to prey upon all manner of game; hence, even though present in but small numbers, it must play an important part in limiting the population of quail, grouse, and pigeons in the higher mountainous districts. It is known to visit mountain ranches in fall and winter and to capture domestic chickens. Quite likely at times rabbits and the larger squirrels also fall victims to it.

During the many weeks which we spent in the Canadian Zone we saw goshawks but four times, and only on one occasion was more than a single individual seen; therefore the species is not to be considered at all common in the Yosemite region. On October 3, 1915, an adult goshawk circled about the head of Glen Aulin, and then made off rapidly down-cañon through the lodgepole pine forest. Its rapid flight through the trees suggested strongly its relationship to the smaller Sharp-shinned and Cooper hawks. Another adult was seen to good advantage in the cañon of Florence Creek on August 26.

Near Ostrander Rocks, on June 23, 1915, a pair of adult goshawks was routed out of a growth of dense red firs in a cañon. They showed much solicitude over the observer's presence, and kept flying about over head, frequently alighting on the uppermost tips of the fir trees and uttering their shrill ringing cries in rapid series of from twelve to thirty-six notes. At this time all of the distinctive field characters enumerated above could be seen to advantage, and when one flew close by, the fine barring on the feathers of the lower surface was easily observed. Search of trees in the vicinity led to the discovery of a nest about sixty feet up in a red fir, supported by the lowermost smaller branches which started from the trunk at that height. The ground below the nest, as in the case of the nest of the Cooper Hawk cited above, was covered with white excrement, suggesting recent or present occupation by young birds.

In Yosemite Valley, on November 1, 1915, Mrs. Jack Gaylor shot an immature female goshawk just as the bird swooped down into her chicken yard. Its crop and gullet were empty. It was reported that five goshawks were killed in the Valley in the fall of 1917. Mr. Donald D. McLean reports that this hawk is occasionally seen in winter in the vicinity of Smith Creek east of Coulterville, altitude about 3000 feet.