1891.] The Origin of the Avifauna of the Bahamas. 529 
furnish food, no land bird could exist there. Increasing vegeta- 
tion finally rendering them habitable, they were ready to receive 
the first-comers of a future avifauna. This, as we shall see, has 
been supplied from various sources, and there have now been 
recorded from the Bahamas about one-hundred-and-fifty-six spe- 
cies and subspecies of birds. The influences which have been 
most active in producing this fauna we may discuss after we have 
reviewed the fauna itself. 
Of the one-hundred-and-fifty-six species, seventy-two are water- 
birds of generally wide distribution, and, with two exceptions, we 
may dismiss them at once as in no way distinctively Bahaman. 
The remaining eighty-four land birds we may divide into non- 
breeding and breeding birds. The first class, or non-breeders, is 
composed of thirty North American species which find in the 
Bahamas either a winter home or a pathway for their migrations 
to and from the tropics. Although, as we have said, the islands 
afford many of these species congenial homes during the winter, 
the migratory habit is evidently too strongly developed to permit 
of their becoming permanent residents. Unless, therefore, they are 
residents in the same latitude on the mainland, apparently in no 
instance have they assisted in populating the Bahamas. 
It is the second class, however, of breeding birds which claims 
our especial attention. Here it is we shall find the truly Bahaman 
species which give character to the avifauna. We owe our 
knowledge of this avifauna largely to the original investigations 
of Dr. Bryant, Mr. Cory, the naturalists of the ‘‘ Albatross,” and 
to Dr. Northrop. It is, however, far from complete. Several 
islands have as yet been unexplored, and we need more exact 
information concerning the distribution of many species. Dr. 
Northrop’s recent paper on the birds of Andros is an important 
step in this direction, and his success in this field may well stimu- 
late and encourage other workers. So far as we at present 
know, fifty-four species of land birds may be considered as 
breeding in the Bahamas. In our study of their relationships 
we may include two species of water birds whose compara- 
my sedentary habits have promoted their differentiation into 
forms. These birds we may divide into two-classes ; 
