An Evaluation of The Habitat Characteristics of Pools Used by Platypuses (Ornithorhynchus Anatinus) in the Upper Macquarie River System, New South Wales.

Abstract

The study conducted during 1993 assessed the habitat characteristics of 36 pools along the upper Macquarie River system. A range of biophysical parameters were assessed at each site, including: pool morphology; riparian floristics and habitat structure; benthic substrate composition; and physicochemical properties. The results of a complementary observation program indicated that 19 of the pools were being used by platypuses. Statistical analyses were carried out to identify significant platypus-habitat relationships. Platypuses were most often associated with long pools with consolidated, angled banks; slow flowing waters; mean depths of one to two metres; low level sand accumulation; abundant native vegetation with overhanging foliage; many instream logs; and, abundant aquatic vegetation. Of these characteristics pool length, pool depth and overhanging foliage were most strongly associated with pool use. Platypuses were sighted using pools ranging from apparently ideal to seemingly unsuitable, based on the habitat analysis, but were most often associated with high integrity areas of the river system. The results illustrate that while habitat usage appears to reflect remarkable adaptiveness, there is a clear preference for pools that have been less disturbed by human activities.