>On Fri, 4 Apr 1997, John Leonard wrote:
>> In Australia there is one species of megapode (Malleefowl) found in the band
>> of mallee across the south of the continent and two species (Scrub Turkey
>> and Orange-footed Scrubfowl) found in rainforest and adjacent habitats down
>> the east coast. However there is not, and hasn't been in Recent times, a
>> species inhabiting dry schlerophyll and woodland down the eastern side of
>> the continent. Why not? Surely if the mallee can support a species, then dry
>> forest and woodland could too.
This is an interesting one. I am only familiar with the Brush Turkey which
I encounter occasionally as I follow a long-term study of the ground-level
birds in Brisbane Forest Park, west of Brisbane, Qld.
My impressions are that there is quite a lot of exchange of birds between the
typical "rainforest" [notophyll closed forest] and "eucalypt forest"
[sclerophyll closed forest], including the brush turkey, and few birds are
confined to only one forest type. Generally, the density
of ground level birds is higher in the notophyll forest. I think that this
might be due to greater productivity in the notophyll leaf litter. Notophyll
leaves have less in the way of oils and tannins and so breakdown more
quickly releasing nutrients to all the other insects, worms and fungi in the
soil ... higher productivity.
A similar argument might explain the brush turkey's preference for "rainforest".
The notophyll leaves will break down more quickly in its mounds, allowing it
to control temperature more readily than would sclerophyll leaves.
I think that the malleefowl relies more on ambient daytime temperature than
leaf decomposition for egg-incubation.. but I could be wrong.
Dr Peter Woodall email =
Division of Pathobiology
School of Veterinary Science Phone = +61 7 3365 2300
The University of Queensland Fax = +61 7 3365 1355
Brisbane, Qld, Australia 4072 WWW = http://www.uq.edu.au/~anpwooda
"hamba phezulu" (= "go higher" in isiZulu)