The geographical distribution of animals, with a study of the relations ...

206 ZOOLOGICAL GEOGRAPHY. [part hi.The Mediterranean and Atlantic Islands.—The various islandsof the Mediterranean are interesting to the student of geographicaldistribution as affording a few examples of local speciesof very restricted range, but as a rule they present us withexactly the same forms as those of the adjacent mainland. 1Their peculiarities do not, therefore, properly come within thescope of this work. The islands of the Atlantic Ocean belongingto this sub-region are, from their isolated position and thevarious problems they suggest, of much more interest, and theirnatural history has been carefully studied. We shall thereforegive a short account of their peculiar features.Of the three groups of Atlantic islands belonging to this subregion,the Canaries are nearest to the Continent, some of theislands being only about fifty miles from the coast of Africa.They are, however, separated from the mainland by a very deepchannel (more than 5,000 feet), as shown on our general map.The islands extend over a length of 300 miles ;they are verymountainous and wholly volcanic, and the celebrated peak ofTeneriffe rises to a height of more than 12,000 feet. The smallMadeira group is about 400 miles from the coast of Moroccoand 600 from the southern extremity of Portugal ; and there isa depth of more than 12,000 feet between it and the continent.The Azores are nearly 1,000 miles west of Lisbon. They arequite alone in mid-Atlantic, the most westerly islands beingnearer Newfoundland than Europe, and are surrounded by oceandepths of from 12,000 to 18,000 feet. It will be convenient totake these islands firstin order.Azores.—Considering the remoteness of this group from everyother land, it is surprising to find as many as fifty-three speciesof birds inhabiting or visiting the Azores ; and still more to1Malta is interesting as forming a resting-place for migratory birds, whilecrossing the Mediterranean. It has only eight land and three aquatic birdswhich are permanent residents ;yet no less than 278 species have beenrecorded by Mr. E. A. Wright as visiting or passing over it, comprising alarge proportion of the European migratory birds. The following are thepermanent residents : Cerchneis tinnunculus, Strix flammed, Passer salicicola,Emberiza miliaria, Corvu* monedula, Monticola cyanea, Sylvia conspicillata,Columba livia, Puffinus cinerevs, P. anglorum, Thalassidroma pelagica.