It seems to me that this is not an entirely new split but in part a return
to some good sense that prevailed prior to Peters 1931 Checklist.
Firstly this change by the IOC affects the name that we call the three
Australian reports but doesn't add to the Australian list although is likely
to add to personal lists. All were seen at the Darwin (Leanyer) Sewage
works, the first in 1999, the second in 2008 and the third in 2009. Niven
McCrie found the first and the second and the third was found by Guy Dutson.
Only the first was submitted and endorsed by BARC so two submissions are
awaited.
For a non-migratory bird, I would accept the argument that on proximity
grounds Tricoloured is the natural assumption to make regarding the species
involved in the Australian reports but going on other cases, not all my BARC
colleagues would agree. The 1999 submission suggested that based on
geographical distribution that bird was most likely Tachybaptus ruficollis
vulcanorum but if that subspecies proved invalid then it would be T. r.
tricolor but stated 'Race not known with certainty since most subspecies are
apparently only separable by measurements and the amount of white on the
secondaries'. In my assessment of that case, I argued that although that was
true, we could narrow the field to just three subspecies, all of which
inhabit Wallacea and the New Guinea region, T. r. tricolor, vulcanorum and
collaris because the bird had deep RED EYES. Elsewhere Little Grebes have an
iris that is yellow (e.g. China & Japan), brown or dark (e.g. Europe), but
NONE are red.
Judging by Adrian Boyle's photo on www.pbase.com/wildlifeimages, the 2009
bird had bright red eyes, identical to the 1999 bird, (compare photos in
Australian Birding March 2000, The Bird Observer December 1999 and Wingspan
December 1999). The eye of the 2008 bird appears a little darker in somewhat
smaller images by Rohan Clarke on that same website. Thus I claim that all
these individuals derived from the population of 'Little' Grebes immediately
to Australia's north now known as TRICOLOURED GREBE.
Note however that some of the taxa currently included in the Tricoloured
complex have yellow eyes but the IOC list flags the likelihood that these
will be split. If/when that happens, we will still know from which group the
Australian vagrants derived.
Mike Carter
30 Canadian Bay Road
Mount Eliza VIC 3930
Tel (03) 9787 7136
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