If you need an accessible version of this item please contact JSTOR User Support

The Numbers of Species of Hummingbirds in the West Indies

David Lack
Evolution
Vol. 27, No. 2 (Jun., 1973), pp. 326-337
DOI: 10.2307/2406972
Stable URL: http://www.jstor.org/stable/2406972
Page Count: 12
  • Download PDF
  • Cite this Item

You are not currently logged in.

Access your personal account or get JSTOR access through your library or other institution:

login

Log in to your personal account or through your institution.

If you need an accessible version of this item please contact JSTOR User Support
The Numbers of Species of Hummingbirds in the West Indies
Preview not available

Abstract

1) The number of species of hummingbirds on each West Indian island is correlated with altitude, mainly because montane humid forest brings in an additional species. 2) Each species differs markedly in habitat, feeding stations or size from the others on the same island. In two instances, a species has a wider habitat on islands where another species is absent than on islands where it is present. 3) Probably 9 or 10 mainland hummingbirds have colonised the West Indies. But nearly every mountainous island has only three species, one small, one large lowland and one large montane, and nearly every lowlying island has only two species, one small and one large, presumably as a result of competition for the available ecological resources. 4) Hummingbirds not infrequently wander between the mainland and the islands, and between the islands, so difficulties of dispersal cannot be responsible for the number of species resident on each island. 5) Geographical replacement on different islands is frequent in hummingbird species of similar size and ecology, though they may have minor differences. That such replacement is due to competitive exclusion is indicated particularly by an example within Puerto Rico, without any geographical barrier, and also by the recent replacement of one species by another in the Virgin Islands. 6) Although hummingbirds may move between the islands, and from the mainland, there is a high degree of endemism, presumably due to the rapid evolution of locally adapted forms.

Page Thumbnails

  • Thumbnail: Page 
326
    326
  • Thumbnail: Page 
327
    327
  • Thumbnail: Page 
328
    328
  • Thumbnail: Page 
329
    329
  • Thumbnail: Page 
330
    330
  • Thumbnail: Page 
331
    331
  • Thumbnail: Page 
332
    332
  • Thumbnail: Page 
333
    333
  • Thumbnail: Page 
334
    334
  • Thumbnail: Page 
335
    335
  • Thumbnail: Page 
336
    336
  • Thumbnail: Page 
337
    337