• DOI:10.1086/285219
• Corpus ID: 86670896

Patterns of Extinction in the Introduced Hawaiian Avifauna: A Reexamination of the Role of Competition

@article{Simberloff1991PatternsOE,
  title={Patterns of Extinction in the Introduced Hawaiian Avifauna: A Reexamination of the Role of Competition},
  author={Daniel Simberloff and William J Boecklen},
  journal={The American Naturalist},
  year={1991},
  volume={138},
  pages={300 - 327}
}

• D. Simberloff, W. Boecklen
• Published 1 August 1991
• Environmental Science
• The American Naturalist

Among introduced passeriform and columbiform birds of the six major Hawaiian islands, some species (including most of those introduced early) may have an intrinsically high probability of successful invasion, whereas others (including many of those introduced from 1900 through 1936) may be intrinsically less likely to succeed. This hypothesis accords well with the observation that, of the 41 species introduced on more than one of the Hawaiian islands, all but four either succeeded everywhere they were introduced or failed everywhere they were introduced, no matter what other species or how many other species were present. Other hypotheses, including competitive ones, are possible. However, most other patterns that have been claimed to support the hypothesis that competitive interactions have been key to which species survived are ambiguous. We propose that the following patterns are true: (1) Extinction rate as a function of number of species present (S) is not better fit by addition of an S2 term. (2) Bill-length differences between pairs of species that invaded together may tend to be less for pairs in which at least one species became extinct, but the result is easily changed by use of one reasonable set of conventions rather than another. In any event, the relationship of bill-length differences to resource overlap has not been established for these species. (3) Surviving forest passeriforms on Oahu may be overdispersed in morphological space, although the species pool used to construct the space may not have been the correct one. (4) Densities of surviving species on species-poor islands have not been shown to exceed those on species-rich islands.