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: 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
_____
===============================
To unsubscribe from this mailing list,
send the message:
unsubscribe
(in the body of the message, with no Subject line)
to:
http://birding-aus.org
===============================
|
