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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