They might be a pest species on the Gold Coast but as they aren't breeding
on the Vic/NSW border where they should be breeding (and haven't bred there
for some time) we can not be cavalier about killing them off (IMO)
If you read this brief article
http://www.abc.net.au/science/scribblygum/november2007/
Ursula Munro who is studying the birds talks about the problems of killing
eggs:
"So what's the problem? Surely we can kill a few nuisance birds and still
have thousands left?
The problem, says Munro, is that ibis can live for a very long time.
"We don't know exactly how long, but one specimen caught in Victoria was 28
years old. We don't know at what age they stop breeding," she says. "We can
go on destroying eggs and nests for years, and not see much of a difference
in the adult population. If we take off the recruits [eggs] we don't see an
immediate effect of this management."
Adding to this complex picture is the fact that most ibis don't stay in
cities all year round. Once they've bred, perhaps two thirds of the
population leave and fly north, a few as far as Papua New Guinea. The young
don't return to the urban areas until they are at least two to three years
old, so it makes it more difficult to figure out how many ibis there are,
says Munro.
She points out several species of ibis that were once common in other
countries are now either near to extinction or locally extinct, including
the sacred ibis from Egypt, the giant ibis from Asia, and the Waldrapp ibis
from Europe and North Africa.
Major agrees: "By destroying the nests and eggs of white ibis to manage
urban populations, you are reducing the population overall [including those
individuals] who could potentially fly back to the Macquarie Marshes to
breed."
No virus found in this outgoing message.
Checked by AVG Free Edition.
Version: 7.5.516 / Virus Database: 269.19.0/1218 - Release Date: 10/01/2008
1:32 PM
===============================
www.birding-aus.org
birding-aus.blogspot.com
To unsubscribe from this mailing list,
send the message:
unsubscribe
(in the body of the message, with no Subject line)
to:
===============================
|
