On Tue, Sep 06, 2005 at 10:56:26AM +1000, Michael Hunter wrote:
> Insecticides, Clearing, Cats, and Currawongs combine to starve,
> expose and predate blue wrens in suburbia. Kookaburras and
> Butcher-birds don't help.
Predation is definitely not evidence that the presence of the predator is
reducing the numbers of the prey species. Predator-removal experiments
often result in the decline of some prey species.
I've seen high densities of Superb Fairy-wrens in combination with high
densities of cats and Pied Currawongs in inner Sydney. Ihe impact the
removal of either predator would have on Superb Fairy-wrens numbers
isn't obvious (to me).
More generally I would have thought Superb Fairy-wrens were a winner from
most (not all) human vegetation modification. The (new) Atlas suggests
that are abundant and increasing so they are certainly getting along
with us.
Andrew
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