Jeremy writes of being sceptical. I would think fishing line/rubbish
explanation is likely. I take Mike's comment to refer to describing that
other causes also exist. About the clams, I wonder how quick they can shut,
is the damage done rapidly by injury on the immediate closing or is it by
staying on the foot for a long time, presumably causing gangrene, and if the
latter, why would the clams do that and not just release and fall off after
a short time? I too have seen Oystercatchers (and gulls) missing their toes
and quite "happy" Pied Oystercatchers with leg bands.
Philip
-----Original Message-----From:
On Behalf Of Jeremy O'Wheel
Sent: Saturday, 23 February 2013 9:11 PM To: Mike Carter Cc:
birding-aus Subject: Re: [Birding-Aus] Short Pied Oystercatcher
Thanks Mike. I was a little skeptical about the fishing line/rubbish
explanation since it seemed unlikely to tangle so tightly as to cut off
circulation, or for birds when tangled to fly away with so much force as to
rip their feet off (not to say that could never happen).
Jeremy
On 21/02/2013 2:28 PM, "Mike Carter" <> wrote:
> Although fishing line and hooks cause the maiming and deaths of many
> birds I do not think it likely that it is the major cause of toe loss
> in Oystercatchers. I suggest two other causes, bird bands and clams
> are to blame. I've often seen Oystercatchers belaboured by up to five
> bands limping badly. Because of this many years ago the Rangers on
> French Island here in Victoria were reluctant to grant and possibly
> refused permission to band Oystercatchers there.
>
> But there may be a more natural cause. The bivalves they seek to eat
> fight back by closing over their toes! David Melville, currently based
> in NZ is currently researching the phenomena for a paper after
> witnessing in China two Bar-tailed Godwits apparently trapped by
> clams. One remained motionless for over three minutes before escaping.
> He asked me for a copy of a note on the subject that I published in
> Australian Birding in Autumn 1999.
>
> This is the gist of the note. On 19 January 1999 on a beach at Ballina
> NSW, I saw an Australian Pied Oystercatcher (OZPO) that was foraging
> in the wash-zone suddenly leap into the air uttering a loud yelp. A
> 3-4 cm bivalve presumably a pipi Donax deltoides had clamped around
> one of its toes. Continuing to call and obviously in some distress it
> flew to a height of 1.5 m shaking its leg vigorously. This dislodged
> the pipi which fell into the sea. The OZPO landed on the dry beach
> supporting itself mainly on the unaffected leg, occasionally lifting
> and shaking the one that had been caught. After several minutes it
> resumed feeding normally. Three of the 52 OZPOs on that beach were
> limping. According to Bo Totterman who studied the OZPOs there and
> incidentally had just found Australia's first South Island Pied
> Oystercatcher (SIPO), one bird known as 'Hoppy' had lost all its toes
> on one foot and the stub end of the other tarsus was clubbed. The
> other two limpers were not so badly disabled. He claimed that there
> was no evidence that the trauma had been caused by bands.
>
> Mike Carter
> 30 Canadian Bay Road
> Mount Eliza VIC 3930
> Tel (03) 9787 7136
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