On Fri, Oct 22, 2004 at 05:00:13PM +1000, Tim Murphy wrote:
> They used to be a big problem in Brisbane, perhaps 15 years or 20 ago, but I
> hardly ever see or hear one now and I used to see 100s every night. Note I
> say, USED TO BE A PROBLEM, the problem is self limiting and the last thing
> to do is to try to poison them or use some kind of control - you'll probably
> end up doing more damage.
I'm far from convinced. Anecdotal reports of post-colonization toad
density declines in the long-term are common, and must be good news.
But I remember hearing Ross Alford from JCU talking about toad censuses
in Townsville. They found considerable annual variability with quite
high density in some years and Townsville must have been colonized 40+
years ago.
Toads can still be a problem at low densities. The apparent extinction
of a Northern Quoll population being monitoried in Kakadu's Mary river
region mentioned here:
http://www.theage.com.au/articles/2003/05/19/1053196523688.html occurred
with the first arrival of toads when few toads could be observed
so presumably their density was low. This is a (severe) short-term
impact, what the long-term impact on the Quolls and other species is
the interesting and unanswered question.
And to add some birding-aus relevent content, I was in Kakadu
last week and managed to visit Gunlom for a third attempt to see
White-throated Grasswren. My chances weren't great in the middle of
a hot day particularly as most of the spinifex near the waterfall had
been burnt. All I found was a Chestnut-quilled Rock-Pigeon coming in
to drink. More amusing was a frog, Litoria meiriana, in the toilets
at Gunlom - they are rocky stream specialists limited to the top end.
Its very incongruous see a frog you associated with crystal-clear pools
in stone country streams in a urinal.
An unusual looking raptor soaring at the Plum Creek road crossing had me
hoping for a Red Goshawk but binoculars turned it into a Square-tailed
Kite. It circled a few times for good views of its distinctive flight.
Andrew
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