SAGE-HEN 275 



wings and sailed off down the valley. His flight was heavy but rapid as 

 he went with the wind. As he left the ground, rather slowly, he uttered 

 a deep hoarse cackle. On other occasions tracks of six or more birds were 

 seen near the same place, and tracks were much in evidence about a small 

 spring in the vicinity where the birds had come down to water. 



Band- TAILED Pigeon. Columba fasciata fasciata Say 



Field characters. — Size and pioi>ortions of domestic pigeon; general effect of color- 

 ation of upper surface bluish gray, of under surface pinkish brown; a distinct dark 

 band across middle of square-ended tail. (See pi. 4;) Flight swift and direct, with 

 steadily flapping wings; leaves perch with a loud clapping of wings. Voice: A deep, 

 rolled, coo'-coo, or too-coo', resembling that of a domestic pigeon. 



Occurrence. — Common summer visitant to Transition Zone on west slope of Sierra 

 Nevada. During winter season, ranges dovrn through Upper Sonoran Zone, following 

 food supply as available. Observed in Yosemite Valley at almost all times of the year. 

 Usually encountered in small flocks in open forests near or in oak trees or berry pro- 

 ducing shrubs. 



A visit to the Yosemite offers to the naturalist, among other attractions, 

 an exceptional opportunity to study Band-tailed Pigeons. These hand- 

 some birds (pi. 4) are likely to be found in the Valley in some numbers 

 at almost all times of the year. They are commonest in spring and fall ; 

 flocks of from ten to a hundred were noted by us almost daily in those 

 seasons. But they were present, also, all summer, though in lesser num- 

 bers, and during winter as well, save when heavy snow covered the trees 

 and the ground. 



Band-tailed Pigeons have the flocking habit strongly developed. To 

 be sure, they scatter out when nesting ; but even during this period, when 

 not actually engaged in caring for eggs or squabs, the parent birds assemble 

 in small flocks for feeding. The gregarious habit of the pigeons probably 

 serves them usefully in two ways : a larger measure of protection from 

 enemies is secured through the increased vigilance possible with many 

 pairs of eyes ; and, by the same means, a better chance of finding adequate 

 food supplies is provided. The individual bird, and hence the species, 

 profits by a certain degree of cooperation. The flocks are loosely con- 

 stituted, and when disturbed while foraging the individuals flush scatter- 

 ingly. At times small companies leave the main flock to seek safety 

 independently. 



Often as we ascended the steep trails which lead out of the Yosemite 

 Valley we would come upon Band-tailed Pigeons sunning and preening 

 themselves on the exposed upper branches of the oaks or cedar trees 

 which cling to the canon walls. Once we noted a group of eight contentedly 

 drinking and preening on a flat rock bordering the rushing waters above 



