ECOCOOY, SYSTEMATICS AND EVOLUTION OF AUSTRALUN FROGS 41
1 sp. These 10 speciea are able to occupy at least part of this inhospitable tract.
The enequal representation of genera in various parts of the continent iighlights the nature of ecological problems facing frogs. Questions relating to these problems can be poaed several way. We can
look a t the characteristics of species from are88 of high uniformly
distributed rainfall, and compare them with species from areas of low
BOUNDARY 0 1 S E M I . ARID
---- 10" IsonYtl
. * I , A 6 O V t 2000 Peat
FIQ. 1. Map of Australia showing: Tropic of Capriaom; land over 2000 feet m height,
boundary of the semi-arid end the 10 in. iaohyet.
but reliable or unreliable seasonal rainfall, or we can look at water
requirements and heat tolerance in all epecies of frogs in the hope that
this will reveal the pre-requisites for e u c d u l colonisation of the
desert. Both the foregoing methode afford good insights into the adaptations of genera and speciee.
Aa alroady indicated the knowledge of the fro@ of eaatern Australia
lags behind that of Western Australia, and with the exception of the
genus Crinia, what follows relates to Western Australia only.