in tivo'-Andalucian Sierras. 459 



would probably bave been seen in a few hours on San 

 Cristobal. This is, moreover, quite in keeping with what 

 has already been said about the comparative scale of the 

 two districts. 



It was also remarkable that in the Sierra Nevada, the 

 corresponding bird- and plant-life seemed to be reproduced at 

 an additional 1500 or 2000 ft, elevation ; thus it was not 

 until the middle zone was reached that San Cristobal's 

 3000 ft. life became general. 



Some aspects of the ornithology of these sierras, M-hich 

 though not new, gain much in interest by coming under 

 personal observation, and provide matter for reflection on 

 general subjects, such as geographical distribution, &c., 

 are : — 



(1) The ready adaptation to the climates of altitudes up 

 to 4000 ft. or more of such species as the Dartford 

 Warbler, Woodlark, Hoopoe, and others, which also 

 breed at sea-level comparatively close to the base of 

 the sierras provided the environment, and presumably 

 food, are suitable to their requirements for repro- 

 duction, although in many parts of the intervening 

 zones there may be no such suitable environment. 



(3) The presence and (apparent) breeding of such species 

 as the Common Wheatear and Skylark at high 

 altitudes Avhicli furnish them with a climate re- 

 sembling that which other individuals, of the same 

 species, find at sea-level thousands of miles further 

 north. 



(3) The little use that migrating birds seem to make of 

 the sierras as a resting-place during their passage ; 

 for instance Chats, Warblers, and Flycatchers of 

 many species passed abundantly through the foothills 

 and lowlands of the Province of Jerez during March 

 and April but were almost entirely absent from San 

 Cristobal, and yet the latter must lie in the direct 

 route of many of the birds. It is presumably the 

 altitude that is objected to, if not for flighting, 

 certainly for alighting purposes. 



