in defence of introduced species

["Chris Sanderson" <>]

Hi Peter,

 

My example of foxes was to point out that there are some situations where control is essential to ensure the survival of a critically endangered species (at Two People's Bay NP that is Noisy Scrub-Bird and Gilbert's Potaroo).  Control programs are certainly not a final solution on continental Australia.  However, I've heard mention that Scaly-breasted Lorikeets are declining in South-east Queensland due to a combination of Rainbow Lorikeets and Common Mynahs stealing their nesting hollows.  In the short term this might not seem like a problem, but with the right control program in place this never need turn into a last ditch effort to save them from extinction.  As I said in my last email on the subject, since lorikeets live so long it will be years before we see the true impact of breeding failures due to Mynahs.

 

Regards,

Chris

Brisbane, QLD

 

On 3/8/06, Peter Woodall <> wrote:

Dear Friends

As with many ecological problems, this is a very complex issue and simple
statements and solutions don't
do it justice.

With the introduced species, some have had a major impact on native species
while others have had a much
more limited impact.  Foxes fall into the former category, House Sparrows,
Red Bishops, White-winged Widows,
(remember those?) into the latter.

While I understand the emotion behind the calls for trapping/shooting
Common Mynas I don't believe that they
will have any real impact on the species.  A sustained campaign may reduce
numbers in a local area for a
while but as soon as it stops they will move back in again.

Look at the case of foxes.  How many thousands/millions have been shot in
Australia (mainly for their pelts)?
Has the overall population decreased at all?

A local, intensive campaign may well eradicate a local population but it
won't be long before immigrants move back into the area again.
Remember that all these problem species produce more young than can survive
locally, as they are moved out of their natal
home range they are looking to establish their own little patch and any
vacant area will soon be colonised.

Unfortunately, I don't believe that Common Mynas will be controlled by
shooting (politically impossible) or by trapping,  except
in a very limited area.

On a brighter note, a couple of years ago I visited a winter roost of
Common Mynas in a southern suburb of Brisbane and watched
as at least four Australian Hobbies were taking off mynas as they came in
to sleep.
Perhaps the answer is to breed up Hobbies.

Peter