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Re: Avian extinction ref.



> Blackburn, et. al. 2004 _Avian Extinctions and Mammalian 
> Introductions on
> Oceanic Islands_ Science, 305:1955-1958 (24 Sept) find that 
> extinction of
> birds on oceanic islands depends upon the diversity of introduced
> mammalian predator species--it is unrelated to the number of 
> herbivorous mammal species.  "These results strongly imply that each 
> successiveaddition of an exotic predator acts to eliminate an 
> additional proportion
> of an island's avifauna."
> 
> Score another targeted extinction to predation.

This is a very interesting paper,and I have actually spoken to Tim a fair bit 
about this project (My old lab group collaborates with his somewhat regularly, 
and he made a couple visits a while back).  I would be careful, however, about 
making conclusions as to what it means.  

Blackburn et al. looked at oceanic islands on purpose, because he suspected 
that island forms should be particularly susceptible to predator introduction.  
He was absolutely cor
rect in this regard, and the sensitivity of island forms to introduction events 
has also been shown (though with less rigor) on previous occasions for several 
different taxa (esp. mammals and birds).

So, the bottom line is that species with highly restricted ranges, especially 
those that are isolated, show a high liklihood of extinction when faced with 
waves of introduced predators over a relatively short time span.  Definitely 
important, but perhaps not a global kill analog.

Cheers,
--Mike Habib