14 



are fond and which may be ascertained from the lists given on other 

 pages of seeds identified in the stomachs examined. The majority 

 of species of birds found in Porto Kico seem to be local in distribu- 

 tion ; that is, they do not wander beyond their own immediate terri- 

 tory, and under proper encouragement and protection their numbers 

 should greatly increase. The tendency is to cut away tree and brush 

 growth at the borders of fields and on waste lands and so to decrease 

 the available shelters for birds. With these conditions righted bird 

 life should multiply and increase to the maximum which can exist 

 on the island. 



INTRODUCTION OF BIRDS. 



Six species of birds are known to have been introduced in recent 

 years into the island of Porto Rico, though only one, the hooded 

 weaver finch (Spermestes cucullata), has spread over a large area. 

 Of the others, the quail (Colinus v. cubanensis), introduced near 

 Vega Baja, is apparently extinct; and the guinea fowl (Numida 

 meleagris), known for many years as feral on this island, is very 

 rare. The South American troupial {Icterus icterus), though found 

 in Gundlach's time in a few localities, has apparently vanished: 

 while the scarlet-cheeked weaver finch (Amandava melpoda) , unlike 

 the other member of the same family, has been known for many 

 years only from the southwestern corner of the island and is still 

 restricted to that range. There are no records to show how, when, 

 or by whom these birds were introduced. The turkey vulture 

 (Cathartes a. aura), found near Guanica, has not extended its range, 

 though conditions are favorable for it over the entire island. None 

 of the exotic species acclimated are injurious, and one, the vulture, 

 would be decidedly beneficial if more common. The hooded weaver 

 finch, at present harmless and living almost entirely on grass seeds, 

 might, if rice culture were again attempted on a large scale, do con- 

 siderable damage. 



After a careful study of the conditions the introduction of in- 

 sectivorous or frugivorous species would seem to the writer to be of 

 doubtful value. Only species of economic importance will here be 

 considered. To cope with the island insect pests at present attract- 

 ing attention, the birds would have to be of moderate size at least. 

 In addition to this they would have to be brought in from near-by 

 islands or from continental tropical areas. In the present state of 

 our knowledge concerning the food habits and general economy of 

 tropical forms not a single species can be confidently recommended. 



Too little is known of the food of tropical birds to merit their in- 

 troduction into Porto Rico. Flycatchers, cotingas, becards, or mem- 

 bers of the family of troupials, brought from the continent or other 

 islands within the Torrid Zone, might prove to be almost entirely 



