The idea that vacant niches do not exist is basically founded on a strict interpretation of Hutchinson's definition. It is the kind of rigid view that holds back science. Invasive species are successful either because the occupy a vacant niche or because they force closer packing of occupied niches.
For example, if you remove all the top predators from a system then lower trophic levels explode, and there is a vacant niche. If you remove wolves, then deer populations grow and you may have to hire hunters to fill the empty niche. I'm not disputing that some introductions are based on fallacious arguments, but invoking the literal word of Hutchinson doesn't contribute much to the discussion. Bill Silvert ----- Original Message ----- From: "Randy Bangert" <[EMAIL PROTECTED]> To: <ECOLOG-L@LISTSERV.UMD.EDU> Sent: Wednesday, November 21, 2007 9:54 PM Subject: Re: Invasives > It seems to me that these exotic gallinaceous birds were really > introduced to have something different to shoot. Using them to occupy > vacant niches appears to just be a convenient excuse foisted on us. > After-all, are there really "vacant" niches? One perspective suggests > that the niche is defined around the species, so 'vacant' niches do > not exist. Another specious triumph for wildlife biology.
