Hi Roger,
I agree, I would not call it a 'given' either and certainly greater scientific
evidence would be needed. However, it is interesting and somewhat suggestive
(but not a proof) that these pristine-plumaged and dark-headed juveniles show
up from August - at a time point when steadi leave their nests and start to
wander around. Apparently, that late in the year, juvenile cautaalready look
paler-headed and their plumage is not as pristine anymore. But again, greater
scientific evidence would be very welcome!
Cheers,
Nikolas
----------------
Nikolas Haass
Brisbane, QLD
________________________________
From: Roger McGovern <>
To: 'Nikolas Haass' <>; 'Sonja Ross' <>;
'Mick Roderick' <>
Cc: 'birding-aus' <>; 'Hal Epstein'
<>
Sent: Monday, November 11, 2013 3:26 PM
Subject: RE: [Birding-Aus] SYDNEY PELAGIC TRIP REPORT - NOVEMBER 10, 2013
Just a couple of comments on Mick’s and Nikolas’s postings.
Mick points out correctly that White-capped and Shy Albatross are split in
Birdlife Australia’s Working List of Australian Birds but they are not split in
the BARC checklist which follows IOC taxonomy. As I understand it (and I am not
involved so may be wrong) BARC adopted IOC taxonomy for the reasons cited in
the past by Tony Palliser but Birdlife Australia has chosen subsequently to use
the Birdlife international taxonomy which renders the two checklists
incompatible. Perhaps Tony Palliser and/or somebody from Birdlife Australia
could throw some light on how this will play out since they should surely be
consistent.
All the points raised by Nikolas and Mick regarding identifying adult and
juvenile White-capped Albatross versus Shy Albatross were again hashed over by
David James and myself on the boat on Saturday. Even the ‘given’ that pristine
dark-headed juvenile birds must be steadi is, I believe, something that is
only supposition due to the disparity in the breeding seasons of the two taxa
and surely needs some greater scientific evidence to become a proven
identification feature in the field?
Cheers
Roger
From:Nikolas Haass
Sent: Monday, 11 November 2013 1:52 PM
To: Sonja Ross; Mick Roderick
Cc: birding-aus; Roger McGovern; Hal Epstein
Subject: Re: [Birding-Aus] SYDNEY PELAGIC TRIP REPORT - NOVEMBER 10, 2013
Hi guys,
One interesting personal observation is that during our August/September
Eaglehawk Neck pelagics (2011, 2012 & 2013) the vast majority of adult Shy
Albatross had bright yellow bases of the culminicorn, suggesting that they all
- not surprisingly - were cauta, which breeds 'just around the corner'.
Interestingly, during our Wollongong and Sydney pelagics in the same season
(i.e. just one or two weeks before or after the above-mentioned TAS pelagics),
the majority of adult(ish) Shy-type Albatross did not show this field mark.
This - together with the tracking data mentioned by Mick
(http://www.seabirdtracking.org/dataset.php) - could indicate that most of the
NSW birds in August/September are steadi.
An alternative - less likely? - explanation is that only the sexually active
(hormone levels) Shy Albatross return to TAS and hence are the brightest. So,
we only get 'dull adult' cauta in NSW?
In favour of the first hypothesis is that from August we also get the pristine
dark-headed juvenile steadi in NSW (as mentioned by Mick, too).
And yes, it would be great if the Sydney pelagic could continue! Fingers
crossed!
Cheers,
Nikolas
----------------
Nikolas Haass
Brisbane, QLD
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