64 ZOOLOGICAL GEOGRAPHY. [part hi. 



starved out and exterminated some of the smaller native 

 rodents. 



Birds. — The birds of the Antilles, although very inferior in 

 number and variety to those of the mainland, are yet suffi- 

 ciently abundant and remarkable, to offer us good materials for 

 elucidating the past history of the country, when aided by such 

 indications as geology and physical geography can afford. 



The total number of land-birds which are permanent residents 

 in the West India islands is, as nearly as can be ascertained from 

 existing materials, 203. There are, in addition to this number, 

 according to Prof. Baird, 88 migrants from North America, 

 which either spend the winter in some of the islands or pass on 

 to Central or South America. These migrants belong to 55 

 genera, and it is an interesting fact that so many as 40 of these 

 genera have no resident representatives in the islands. This is 

 important, as showing that this northern migration is probably a 

 recent and superficial phenomenon, and has not produced any 

 (or a very slight) permanent effect on the fauna. The migratory 

 genera which have permanent residents, and almost always 

 representative species, in the islands, are in most cases character- 

 istic rather of the Neotropical than of the Nearctic fauna, as the 

 following list will show ; Turdus, Dendrosca, Vireo, Polioptila, 

 Agelmus, Icterus, Contopus, Myiarchus, Tyrannus, Antrostomus, 

 Chordeiles, Coccyzus, Columba. By far the larger part of these 

 birds visit Cuba only ; 81 species being recorded as occurring 

 in that island, while only 31 have been found in Jamacia, 12 in 

 Porto Rico and St. Croix, and 2 in Tobago and Trinidad. 

 Setting aside these migratory birds, as having no bearing on the 

 origin of the true Antillean fauna, we will discuss the residents 

 somewhat in detail. 



The resident land-birds (203 in number) belong to 95 genera 

 and 26 families. Of these families 15 are cosmopolitan or 

 nearly so — Turdidae, Sylviidae, Corvidae, Hirundinidae, Frin- 

 gillidae, Picidae, Cuculidae, Caprimulgidae, Cypselidae, Trogonidae, 

 Psittacidae, Columbidre, Tetraonidae, Falconidae, and Strigidae; 

 5 are American only — Vireonida% Mniotiltidae, Icteridse, Tyran- 

 nidas, Trochilidae ; 4 are Netropical only or almost exclusively — 



