Hi Lawrie,
You asked for information concerning the "Sunbird" paper
proposing that the Heron Island Silvereye (Zosterops lateralis
chlorocephala) be regarded as a separate species.
I will quote from the paper:
ABSTRACT
The Capricorn White-eye was first described as Zosterops chlorocephalus in
1910, but since 1926 it has been treated as a a subspecies of the Silvereye
Zosterops lateralis in official checklists and monographs. It is restricted
to the wooded cays of the southern Great Barrier Reef, forming a rapidly
differentiating metapopulation. Recent studies revealing its distinctive
morphology, genetic isolation from other forms of Z. lateralis and unique
life history on coral cays, indicate that the treatment of chlorocephalis as
a separate species within the lateralis superspecies may be appropriate.
......
CONCLUSION
The Capricorn White-eye has a well-defined distribution and nowhere is it
sympatric with any other form of Zosterops during the breeding season. It
is isolated genetically from the most closely related subspecies of
Zosterops lateralis on the Australian mainland. No hybridisation with the
mainland forms is evident, at least on Heron Island where migratory mainland
forms appear regularly in winter. Unlike other subspecies of Z. lateralis
in Australia with overlapping morphometric measurements (Schodde & Mason
1999), The Capricorn White-eye is considerably larger and has longer tarsus
and bill lengths than any of the related mainland forms. Although the
history of its differentiation may be recent, its distinctness from other
forms is clear. Thus the current status of Zosterops lateralis
chlorocephalus needs to be reviewed taxonomically with a view to treating it
as a separate species within the lateralis superspecies.
[End of quote}
Not being a twitcher, my symp
thies are generally more with lumpers than
splitters, but in this case there is no doubt that the coral cay population
should be regarded as separate species. You need to read the ten pages of
the paper between the abstract and the conclusion and assess the data for
yourself, but I submit that rarely if ever before has such a proposal been
based on such detailed and extensive data.
The author, Emeritus Professor Kikkawa (Zool., University of Qld.) has, with
his students and collaborators, been studying the Heron Island White-eyes
for over 30 years. I gather that at one stage it was generally held that he
knew every White-eye on the island by its first name. I quote again from
the paper:
"Although birds of intermediate size were found among some 10,000 live
specimens of the island form examined, no mating between the mainland form
and the island form on Heron Island was observed from 1979 to 1993, when
over 150 breeding pairs were being monitored annually."
And finally, I can't resist adding one more quote:
"In winter the island birds appear to be more aggressive that mainland
birds (Morris 1968) and make indiscriminate attacks on opponents in crowded
conditions (Kikkawa & Wilson 2002). They also inflict physical wounds on
starved migrants on Heron Island (Kikkawa 1970) where more heavily built
bodies, stronger legs and larger bills are seen as advantages in agonistic
encounters."
I reckon any twitcher who has been to Heron Island will have seen enough
White-eyes to be sure they included the island form and can now, in good
conscience, add a tick to their list.
Syd Curtis
>
> A very rapid perusal of a print copy of today's copy of "The Australian"
> mentioned that the taxon
> formerly known as status by Kikkawa et al. in a paper published in the
> latest QOS "Sunbird". It
> looks like we now have a species called the Capricornia Whiteye (Z.
> chlorocephalus) - the only bird
> species endemic to the Great Barrier Reef system. Nothing in the online "Aus"
> to post here. I'm
> just wondering if any "Sunbird" subscribers could tell us more about the basis
> on which this
> taxonomic decision has been made????????
>
> L.
>
> +++++++++++++++++++++++++
> Lawrie Conole
> 17 Stafford Street
> NORTHCOTE Vic 3070 AUSTRALIA
> <> or <>
> Ph 9486 4542 Mob 0419 588 993
>
> Senior Ecologist
> Ecology Australia Pty Ltd
> 88 B Station Street
> FAIRFIELD Vic 3078 AUSTRALIA
>
> www.ecologyaustralia.com.au
> BH 03 9489 4191 Mob 0419 588 993
> Fax 03 9481 7679
> +++++++++++++++++++++++++
>
> Birding-Aus is on the Web at
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