ISLAND COMMUNITIES 523 



cemetery of Hamburg at Ohlsdorf has about an equal number, and 

 the Seeburg estate at Langensalza has no less than 61 breeding species 

 in an area less than 1 sq. km. The Azores, with an area of 2388 sq. km., 

 have only 34 breeding species; the Comoro Islands, with 1972 sq. km., 

 only 53 species; the Bermudas, with 50 sq. km., only 13. Continental 

 islands exhibit the same relations. Germany has about 90 species of 

 mammals, Scandinavia 60, Britain 40, Iceland only 22 (see p. 132). 

 Although the number of species is small, the number of individuals may 

 be large. There were vast numbers of birds on the Azores at the time 

 of their first settlement, and it is reported that pigeons settled on the 

 hands, shoulders, and heads of the colonists. 20 The fact that many 

 insular species have few individuals, such as the nestorine parrots of 

 the islands near New Zealand, the extinct starling Fregilupvs varivs on 

 Bourbon, or the flycatcher Monarches dimidiata on Rarotonga, is not 

 necessarily due to insularity. The same may hold with continental 

 species, as in the hummingbirds of the Andes, which, however, are 

 also environmentally isolated. 



A peculiarity of island faunae, which is probably referable to their 

 spatial limitations, is the dwarfing of both birds and mammals, in 

 strange contrast with the converse phenomenon of giantism also found 

 in insular birds. The birds of Corsica and Sardinia are mostly smaller 

 than the directly related forms on the mainland. The birds of the 

 Canary Islands are likewise frequently smaller than the related species 

 in Europe. Among many complicating factors, the Bergmann Rule 

 must be remembered in this connection. Degeneration in size in 

 mammals on islands seems to be well established. 21 Races of ponies 

 are notably numerous on islands — the Shetlands, Iceland, Oeland, 

 the islands of Brittany, Sardinia, and Corsica, the Cape Verde Is- 

 lands, Timor, Bali, Sumba, and the Japanese Islands. The large 

 English horses introduced from Australia to the South Sea Islands 

 become small after a few generations. Deer become dwarfed on islands, 

 as in those introduced in Cuba, 22 the small insular race of the water 

 deer on Bawean (Cervus equinus kuhlii) , or the sika deer of Japan, 

 which reaches a height of only 813 mm. at the withers as compared 

 with 1117 mm. of the continental form. 23 The small buffalo of Mindoro, 

 in the Philippines (Bubalus mindorensis) , and the still smaller dwarf 

 buffalo of Celebes (Anoa depressicornis) represent the water buffaloes 

 of the mainland. The gray fox of Catalina Island does not reach the 

 size of the mainland form in California. The mammals of Sardinia, 24 

 equally with those of Mexiana Island 25 in the mouths of the Amazon, 

 are uniformly smaller than the same species on the adjacent mainland. 



