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Little Grebes in Darwin: Eurasian or Tricoloured

To: "Steve Potter" <>, "'Nikolas Haass'" <>, <>, <>
Subject: Little Grebes in Darwin: Eurasian or Tricoloured
From: "Mike Carter" <>
Date: Thu, 8 Sep 2011 17:28:04 +1000
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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