I?m rather puzzled by the distribution of the Olive Whistler, in
particular its absence or scarcity from the area between about the
Illawarra region and the Hunter region of NSW.
In 16 years of birding in the Blue Mountains west of Sydney, I?ve never
seen or heard it in this area. It?s not listed in Smith & Smith?s ?Fauna
of the Blue Mountains? (1990) and the Atlas of Australian Birds
indicates a gap here (at latitude 33 degrees S). I?m not aware of it
ever occurring in the Blue Mtns Bird Observers? records either.
However, Morris, McGill & Holmes? ?Handlist of Birds in NSW? (1981)
notes that the southern population extends north to Mount Wilson (which
is in the northern Blue Mtns). Pizzey & Knight also lists its range as
including the Blue Mountains. Such Blue Mountains records would
certainly be unusual and perhaps this reflects a declining range?
In trying to understand its absence from this area, I note that the
southern and northern birds are regarded as separate subspecies ?
Pachycephala olivacea olivacea in the south and P.o. macphersoniana in
the north ? and that these differ in their habitat requirements. P.o.
macphersoniana is apparently found north of the Hunter Valley and
favours beech forest, so presumably any birds which did occur in or near
the Blue Mountains would be of the southern race. Certainly we have
plenty of wet eucalypt forest and woodland with dense understorey which
as far as I can see would be suitable habitat. (Perhaps those with more
knowledge of the species can tell me if I?ve overlooked some important
factor.)
I wouldn?t be surprised if they occur in small numbers in Kanangra-Boyd
or on basalt caps like Mt Wilson further north in the Wollemi N.P. (e.g.
Coricudgy) though I?ve never found them in these places.
Can anyone offer some insight on this? Is the gap in its distribution
due to a lack of suitable habitat or to some other effect of its
evolutionary history? Is this species declining overall? Has anyone seen
them in the Blue Mountains or anywhere else on the NSW Central
Tablelands? If so, in what habitat?
Thanks for any info,
Carol
Carol Probets
Katoomba NSW
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