82
A. R. BUIN
The interpretation that the genera and many species are of Tertiary
age indicates a high degree of environmental stability in some a r m of
Australia since that time. The montane beech forests (Nd7t.o&~~
moorei) on the-New South Wales/&ueensland border are clear evidenoe
that such is the cam However, similar examples are not eaay to find in
the drier interior of tho continent where presumably the Australian
deserts have existed for a very long time.
In south-west Australia, Balme and Churchill (1959) have reported
a fossil flora, including Nothofagus and podocarps, of upper Eocene or
Lower Oligocont: age at Coolgardie, Lat. 31"57's Long. 121'11'E.
Cookson (1963) and Cookson and Pike (1963, 1964) have reported a
flora of similar age containing PhyZbcWus and podocarps from
Pidinga, Lat. 31"s Long. 131" 30'E, and at Cootabarlow (East of Lake
Frome, South Australia). These areas now receive from 5 to 10 in.
(127-254 mm) rain/annum. Thus it would seem that the deserts of
southern Australia are younger than the early Tertiary. Conversely the
fossil plant record suggests that the last time that the high rainfall,
wet-forest frogs could interchange between eastern and western Australia would have been during the late Eocene-Early Oligocene. In this
regard it is of interest to note that, no genus is unique to the deserta
or arid areas. Furthermore, the sympatric occurrence of several speciea
of the one genus is unusual. Cyckwana (two speciee) and N e o b a t d u a
(three species) are examples.
It is conspicuous that there are different adaptive modes for what
might be broadly termed the three characteristically Australian environments. These are set out in Table VIII.
The most meaningful discussion of ecology is only possible at the
species and population level. Unfortunately analysis at this level has
not proceeded very far. Species have been distinguished by at least
two of tho following: (i) morphology, (ii) differences in male breeding
call, (iii) genetic differences as shown by inviability when hybridisation
experiments have been carried out. Examplea of population distinctness
unaccompanied by differences in male call are not at present recognised
nomenclatorially, e.g. the sand and clay races of C. insignifera.
I am hopeful that, in Western Australia, all the species populations
have been identified. The prospect for the future is that detailed interand intra-species ecological studies are now possible. Because of certain
difficulties such as the burrowing habit and the roadlesa nature of the
country over most of the range of many species, these studies will have
to be confined to certain species. The genus Crinia offers the best scope
for field studies since many populations can be sampled throughout the
year and individuals can be marked. The polymorphism present in
many species affords an opportunity for studying locally adapted gene
A. R. BUIN
The interpretation that the genera and many species are of Tertiary
age indicates a high degree of environmental stability in some a r m of
Australia since that time. The montane beech forests (Nd7t.o&~~
moorei) on the-New South Wales/&ueensland border are clear evidenoe
that such is the cam However, similar examples are not eaay to find in
the drier interior of tho continent where presumably the Australian
deserts have existed for a very long time.
In south-west Australia, Balme and Churchill (1959) have reported
a fossil flora, including Nothofagus and podocarps, of upper Eocene or
Lower Oligocont: age at Coolgardie, Lat. 31"57's Long. 121'11'E.
Cookson (1963) and Cookson and Pike (1963, 1964) have reported a
flora of similar age containing PhyZbcWus and podocarps from
Pidinga, Lat. 31"s Long. 131" 30'E, and at Cootabarlow (East of Lake
Frome, South Australia). These areas now receive from 5 to 10 in.
(127-254 mm) rain/annum. Thus it would seem that the deserts of
southern Australia are younger than the early Tertiary. Conversely the
fossil plant record suggests that the last time that the high rainfall,
wet-forest frogs could interchange between eastern and western Australia would have been during the late Eocene-Early Oligocene. In this
regard it is of interest to note that, no genus is unique to the deserta
or arid areas. Furthermore, the sympatric occurrence of several speciea
of the one genus is unusual. Cyckwana (two speciee) and N e o b a t d u a
(three species) are examples.
It is conspicuous that there are different adaptive modes for what
might be broadly termed the three characteristically Australian environments. These are set out in Table VIII.
The most meaningful discussion of ecology is only possible at the
species and population level. Unfortunately analysis at this level has
not proceeded very far. Species have been distinguished by at least
two of tho following: (i) morphology, (ii) differences in male breeding
call, (iii) genetic differences as shown by inviability when hybridisation
experiments have been carried out. Examplea of population distinctness
unaccompanied by differences in male call are not at present recognised
nomenclatorially, e.g. the sand and clay races of C. insignifera.
I am hopeful that, in Western Australia, all the species populations
have been identified. The prospect for the future is that detailed interand intra-species ecological studies are now possible. Because of certain
difficulties such as the burrowing habit and the roadlesa nature of the
country over most of the range of many species, these studies will have
to be confined to certain species. The genus Crinia offers the best scope
for field studies since many populations can be sampled throughout the
year and individuals can be marked. The polymorphism present in
many species affords an opportunity for studying locally adapted gene