You are not currently logged in.
Access your personal account or get JSTOR access through your library or other institution:
If You Use a Screen ReaderThis content is available through Read Online (Free) program, which relies on page scans. Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Ecological Compatibility of Bird Species on Islands
P. R. Grant
The American Naturalist
Vol. 100, No. 914 (Sep. - Oct., 1966), pp. 451-462
Stable URL: http://www.jstor.org/stable/2459244
Page Count: 12
Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Preview not available
The difficulties of coexistence on islands for ecologically similar species of birds are indicated by the paucity of homogeneric species, and by the tendency for their bill lengths, and hence their feeding characteristics, to diverge. Members of the most similar pair of homogeneric species on the Tres Marias Islands differ in bill length by 21%. This is greater than the difference between members of 12 out of a total of 14 mainland pairs which are each represented by one species only on the islands. It is suggested that in some instances both members of the mainland homogeneric pairs have reached the islands, but that one member has been eliminated due to interactions arising from mutual ecological incompatibility. It is further suggested that this process has been important in the adjustment of number of species to island area.
The American Naturalist © 1966 The University of Chicago Press