At 21:49 27/09/98 +1000, Nigel wrote:
>I have only just found about this species of bird. It is not in my (old)
>Slater Field Guide. Was this once considered to be a sub-species of the
>Little-Wattle Bird, or is it still considered by some to be such?
>Furthermore, where can they be located and are they common in suburban
>Melbourne gardens?
>email:
>
The "Little Wattlebird" of old was treated for the first time ever as two
species in the 2nd edition of the Readers Digest Complete Guide to
Australian Birds edited by Schodde & Tidemann (1986). A thourough
scientific argument has not been published in an acredited journal (or even
a photocopied leaflet). The argument was accepted by Sibley and Munroe
(1990) in their world checklist. Subsequently the split was not accepted by
the RAOU (Now Birds Australia) in their 1994 Checklist: "The Taxonomy and
species of Birds of Australia and its Territiories" by Christidis & Boles.
This checklist is considered to be the "official" word on taxonomy and
nomenclature of Australian Birds. Such status comes only by consesus or
agreement, not by any binding rule. Anyone is free to disagree with
Christidis & Boles. Most journals and clubs and field guides elect to
follow it because it is good. The Federal Gov. has adopted it as the base
species list for several projects including the CAVS database and the
Zoological Catalogue.
The approach of Christids & Boles differs from most other checklists in
that they took the arguments put forth in the scientific literature
regarding taxonomy etc and judged the arguments on their merits. If the
argument was compelling it was followed. In the case of the Wattlebird the
argument for splitting them (as published) was not found to be convincing.
If more convincing arguments are published then the next Birds Aus.
checklist may accept them. But it is unlikely that a split will be accepted
just because it is "popular" or "appealing" or because it appears in field
guides.
Below is the analysis of the argument regarding how many species of Little
Wattlebird should be recognised, from Christidis & Boles (1994, p. 66).
Remeber that the approach is make no change unless the arguments are
convincing.
>>>>>>>>>>
The eastern and western populations of Anthochaera chrysoptera (chrysoptera
and lunulata, respectively) were treated by Schodde & Tidemann (1986) as
separate species (see also Schodde 1981a: 70) on the basis of differences
in plumage, eye colour and clutch size. Separation of these forms was
accepted by Sibley & Monroe (1990). Schodde & Tidemann (1986) claimed that
adult chrysoptera has pale blue irides and adult lunulata has chestnut
irides, stating that `eye colour is the most obvious clue to specific
status'. The situation is not so clear cut. Rogers et al. (1990) recorded
variable iris colour in Victorian birds, ranging from reddish brown to grey
or turquoise with brown inner rings. In Longmore (1991: 55), there is a
photograph of an adult eastern chrysoptera with chestnut-brown irides.
Without a proper assessment of all the characters involved it is premature
to recognise lunulata as a species separate from chrysoptera.
>>>>>>>>>>>>>>>>>
Of course, this argument is only about "species" limits which is very much
a human concept. There is certainly a difference between eastern (Brush)
and Western (Little) populations of this complex. The spanner in the works
is that it is just about impossible to have a consistent definition of
species, subspecies etc.
Cheers,
David James
PO BOX 5225
Townsville Mail Centre 4810
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