ISLAND COMMUNITIES 



525 



one of these, Mystacina tuberculoid, searches for insects by climbing 

 about on tree trunks and branches as well as in the air. 30 Fruit bats 

 are not uncommon on the islands of the western Pacific. It is interest- 

 ing that a number of insular bats have taken to fish eating. Such 

 forms cross straits and wide stretches of ocean, and fail to form local 

 races on islands. Thus Noctilio leporinus 31 ranges widely in the West 

 Indies. 



Fro. 131.— Insects with vestigial wings from Kerguelin. a, moth, Pringleopm 

 kerguelensis, X 2; b, fly, Apetenus litoralis, X 9. After Enderlein. 



Water birds tend to have a separate community for 200 miles about 

 an oceanic island or archipelago. The marine fishes also form more or 

 less characteristic island littoral communities, the composition of which 

 is strongly affected by the prevailing currents, and the numbers present 

 depend on the amount of nutrient material washed in from the land. 

 Small desert-like islands in the Atlantic have noticeably fewer marine 

 fishes along their shores than islands with fertile soil that lie in regions 

 with good rainfall. 



BIBLIOGRAPHY 



1) Peschel, 1876, Neue Probleme vergl. Erdkunde, p. 64 ff. — 2) Baur, 1891, 

 Amer. Nat., 25, p. 217-229 & 307-326; Pilsbry, 1900, Proc. Acad. Nat. Sc, Phila., 

 1900, p. 568-581.— 3) Wallace, 1881, Island Life, p. 306.— 4) Scott, 1932, Nature, 

 130, p. 797-798.-5) Martens, 1875, Preuss. Exped. Ostasien, 1, p. 316.— 6) Bou- 

 lenger, 1905, Nature, 72, p. 421.— 7) Greef, 1882, SB. Ges. Natw. Marburg, 



