56 BULLETIN OF THE -NUTTALL 



as contrasted with the unsuspicious nature of the Rufous-backed, is 

 quite remarkable. They seem to possess a larger share than usual 

 of the courage and pugnacity which is so constantly displayed in 

 birds of this fixmily. Not only do they always come off the victors 

 when chance encounters take place between them and the Rufous- 

 backs, but Mr. Allen has seen a pair attack and put to rout a Red- 

 tailed Hawk ; while, as he remarks, " Sparrow-Hawks have no 

 chance at all with them." He has often seen the little fellows in 

 hot chase after these latter birds, and their only care seemed to bo 

 to get out of the way as soon as possible of foes so determined. 



The Rufous-backed Hummer, on the contrary, frequents the 

 thickets, and is always unsuspicious and readily approached. The 

 different localities they affect may indicate a difference in the flow- 

 ers from which they obtain their food. 



Habitat. The habitat of Selasphorus alleni seems to be con- 

 fined to the coast district of California, though subsequent investi- 

 gation may show that it extends its range to the northward. It 

 appears to be strictly limited to the western slope of the Sierras, 

 and may indeed wander but a short distance from the coast. It is 

 thus very local, while the *S'. rnfus has a very widely extended habi- 

 tat. Few species, indeed, of the family range over as many degrees 

 of latitude as this, which appears equally at home in the valleys 

 and elevated table-lands of sub-tropical Mexico and in the less invit- 

 ing regions of Southern Alaska, while it occupies in summer most 

 of the intermediate ground. Specimens are in the Smithsonian 

 collection from Sitka, which forms its most northern recorded local- 

 ity. In the interior it appears to be of less general occurrence than 

 in the region Avest of the Sierras, though this apparent absence is 

 doubtless due in part to our lack of knowledge of the Avifauna, 

 especially of the northern interior. The eastern slope of the Sier- 

 ras is apparently occupied by it throughout their whole length. Mr. 

 Ridgway found it in autumn in the East Humboldt Mountains, and 

 Dr. Coues in Montana, and it may be said to occur over most of the 

 Rocky Mountain region, either as a summer resident or as a fall 

 migrant. Dr. Coues is the only one who has found it breeding in 

 the interior, but I think it probable that not only the mountains 

 about Fort Whipple, which formed his field of observations, but the 

 mountain-fastnesses throughout the Territory of Arizona, and also 

 in New Mexico, and perhaps in Southern Colorado, may furnish the 

 species a summer home. Certain is it that in August this Hum- 



