Re: 400 Dead Pink-ears at WTP, Werribee

To: Bob Forsyth <>
Subject: Re: 400 Dead Pink-ears at WTP, Werribee
From: Peter Woodall <>
Date: Fri, 02 Dec 2005 09:06:30 +1000
Hi everyone

I think that Bob is on the right track. If botulism is involved, it is caused by
a bacterium Clostridium botulinum which is anaerobic, i.e. it can't survive and
multiply in air/oxygen. Therefore in nature it is often found at the edges of water bodies
with much rotting vegetation which depletes the oxygen in the water and mud.
C. botulinum is very widespread but only causes a problem when the environmental
conditions are right for it to multiply.
The bacterium produces a neurotoxin that seems to affect the muscles of neck
and wings first, preventing flight and causing the head to drop, and later death.
These signs are fairly diagnostic.

If other species were not affected they may have been feeding in different areas or
different depths of water.
Some species (like raptors) seem to have greater resistance to the toxin and can
feed on carcasses without becoming affected themselves., but I think that most
waterfowl are quite susceptible.
It is very widespread in North America, causing thousands of deaths each year.
There are far fewer documented reports of it from Australia (I published on an
outbreak of it in the Brisbane Valley in the 1970's) but I suspect that it is
widespread but often overlooked.


At 07:21 PM 1/12/2005 +1000, you wrote:
G'day all,

It could be that is that the Pink-eared Ducks have a different feeding regime to other waterfowl ? They feed by filtering their food from the surface of the water whereas other species dabble from below the surface ?

So, if a poison of some sort is floating on the water they would be a goner !

I am always amused that our Pink-eared frequently circle around closely behind each other in twos or threes with their beaks almost up the preceding duck's bum.

Regards from
Bob Forsyth
Mount Isa, NW Qld.

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