RANGE BASE OR REFUGE AREAS 49 



Range Base or Refuge Area II. : This area in- 

 cluded all the now submerged land in the Mediterranean 

 west of say E. long. 20°, and extended as far south as 

 the northern coast-line of that ancient sea which once 

 occupied the Sahara. It also included the peninsula of 

 which the Canary Islands and Madeira now form the 

 few lingering relics, and the additional Atlantic coast 

 area which would be obtained by making the contour 

 of 100 fathoms represent the possible coast-line of this 

 period. The land of this area which now endures con- 

 sists of the Spanish peninsula, Alboran Island, the 

 Balearic Islands, Corsica, Sardinia, Italy, Sicily, Malta, 

 a portion of Tripoli, the whole of Tunis, Algeria, and 

 Morocco, together with the Canary Islands. This area is 

 by far the most important one, so far as British birds are 

 concerned. It formed the chief, nay probably the only 

 range base of nearly all the species that now breed in our 

 islands, as well as of most of the avian life that had been 

 exterminated by the glaciers and climatic changes in all 

 regions lying directly to the north of it. The climate of 

 this region in the southern portions was probably as genial 

 as now, even at the climax of the glacial era ; whilst in 

 the northern portions, although at that period more rigor- 

 ous than now, it was sufficiently genial to admit of the 

 constant existence of temperate plants and animals 

 within its limits. The summers in the northern portions 

 of this area were probably always as favourable to bird- 

 life as now, nay even more so, if at times they were some- 

 what shorter ; whilst the winters of the southern portions 

 were always marked by those genial conditions which 

 are so imperative to the needs of such vast numbers of 

 species {conf. Map, p. 71). 



