Not sure where or what the tug boat was doing before the bird was found in
it. But it is also possible that the thrush hopped onto the tug from any
ship that was already tied up in port, even if the tug did not assist them
into port.
Looking at the shipping lists for the Port of Esperance for that week
<http://www.esperanceport.com.au/shipping.asp> ships were being loaded with
cargo that were bound for Singapore and Chinese and Japanese ports. There's
no information where these ships had come from before arriving at Esperance,
but if one assumes that they are making return journeys to their ports of
origin, then all these ships potentially sailed southwards along the east
Asian coastline and/or between islands of South-east Asia, intersecting the
northern migration route of the Siberian Thrush.
Stephen Ambrose
Ryde NSW
-----Original Message-----
From:
On Behalf Of Mike Carter
Sent: Wednesday, 13 July 2011 7:15 PM
To: Stephen Ambrose; 'Simon Mustoe'; ;
Cc: John Darnell
Subject: Provenance of the ex-Siberian Thrush
What isn't yet clear, to me anyway, is where the tug had been nor what it
had been doing. Was it shepherding a ship into port, returning from
assisting a departing vessel locally or from a longer voyage for whatever
reason? What is clear is that the bird was damaged but otherwise in good
condition, i.e. not fly-blown, rotten or degraded. Thus it was not long
dead before found unless stored in a freezer. Ship assistance per se is not
now regarded as a barrier to acceptance but deliberate carriage of course
is. Maybe we should know more about the tugs movements. Tiger Shrike was
added to the Australian list by Christidis & Boles after being found dead at
another WA port and rather naughtily before acceptance by BARC, and as if to
prove that decision was justified, has since been seen alive on Christmas
Island, Ashmore Reef (twice) and Browse Island. I know of those records
because I saw them all!
There is no doubt as to the species identity and age, an immature male, but
as to the subspecies, I couldn't say. What does seem odd to me is that a
Siberian Thrush would not be in adult plumage by mid June but others suggest
that the stress of being misplaced might have delayed its moult. Most
vagrants are immature birds.
Mike Carter
30 Canadian Bay Road
Mount Eliza VIC 3930
Tel (03) 9787 7136
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