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The platypus ( Ornithorhynchus anatinus ) is one of the world’s most evolutionarily distinct mammals, one of five extant species of egg-laying mammals, and the only living species within the family Ornithorhynchidae. Modern platypuses are endemic to eastern mainland Australia, Tasmania, and adjacent King Island, with a small introduced population on Kangaroo Island, South Australia, and are widely distributed in permanent river systems from tropical to alpine environments. Accumulating knowledge and technological advancements have provided insights into many aspects of its evolutionary history and biology but have also raised concern about significant knowledge gaps surrounding distribution, population sizes, and trends. The platypus’ distribution coincides with many of Australia’s major threatening processes, including highly regulated and disrupted rivers, intensive habitat destruction, and fragmentation, and they were extensively hunted for their fur until the early 20th century. Emerging evidence of local population declines and extinctions identifies that ecological thresholds have been crossed in some populations and, if threats are not addressed, the species will continue to decline. In 2016, the IUCN Red Listing for the platypus was elevated to “Near Threatened,” but the platypus remains unlisted on threatened species schedules of any Australian state, apart from South Australia, or nationally. In this synthesis, we review the evolutionary history, genetics, biology, and ecology of this extraordinary mammal and highlight prevailing threats. We also outline future research directions and challenges that need to be met to help conserve the species.

The bird communities of six riparian woodland sites are described and compared with those of eight terrestrial woodland sites in the Central Tablelands near Bathurst, New South Wales, Australia. Riparian woodland, where still present in the Central Tablelands, is dominated by either relatively narrow strips of Casuarina cunninghamiana along stream banks or the less restricted Angophora floribunda trees associated with Eucalyptus melliodora?E. blakelyi woodlands. Four of the riparian sites were located within cleared agricultural land and two were located within a relatively large nature reserve. Bird censuses along a strip transect were conducted twice per season from spring 1993 to summer 1996. The riparian woodland communities contained within the cleared landscape of the Bathurst basin were found to support a diverse avifauna, a mix of woodland-forest and species associated with agricultural landscapes. Extensive observations of individual birds at riparian sites indicate that the tree canopy is the most widely used microhabitat stratum. While native riparian woodlands are generally degraded, their connectivity and stabilizing function (actual or potential) identifies them as a critical landscape component in maintenance or restoration programmes. Hence it is suggested that riparian strips could form the basis for rehabilitation initiatives within this landscape. Fenced plantings of endemic tree species supplemented by native understorey species could be linked with existing vegetation to enhance landscape connectivity. It is crucial that landholders become aware of the importance of riparian vegetation for nature conservation and stream stabilization. Incentives should be provided to landholders to encourage these areas to be fenced from stock in order to protect them from further degradation in a significantly disturbed ecosystem.

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.

This paper examines historical evidence on the occurrence and status of an important landscape element in the Central Tablelands of New South Wales: the swampy meadow/chain of ponds landform. Our findings reject the notion that it is possible to reconstruct this landform as it was at the time of early European settlement, based solely on early colonial documents. Furthermore the analysis of such documents should be used with appropriate caution when benchmarking this landform. These conclusions have been reached by analysing 826 nineteenth-century portion plans, 18 early explorers and settlers' journals, letters and maps, and nine Surveyor General's maps and plans. We suggest that our findings have significant implications for developing management and restoration strategies, better informing conservation initiatives and the development of policies aimed at protecting, conserving and restoring the swampy meadow/chain of ponds landform. Our experience suggests that researchers involved in historical analyses of documents for similar purposes should be wary about factors such as the limitations and reliability of source data, unwarranted interpretations and the imprecise and/or contradictory use of terms. We also suggest that the possible subjective views of some observers, particularly those with limitations in interpreting such a landform, are further reasons to be cautious. If these factors are not taken into account it is very likely to result in a flawed interpretation. We conclude that both landform awareness and other perceptions of an observer at the time of early European settlement may present a hitherto unrecognised subjective element in this and other analyses which could limit the precision of historical reconstruction, without resort to other complementary methods.

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Since European settlement this landscape has been dramatically altered resulting in a loss of native vegetation cover, destruction of soil quality and structure, disruption of the landscape hydrology and the introduction of pests and weeds (Bauer and Goldney 2000;Letnic 2000;Kerle et al. 2007;Windsor et al. 2004 ABSTRACTThe Central West and Lachlan Catchments lie west of the Great Dividing Range in central NSW and have been subjected to extensive land clearing, grazing and agricultural pressures beginning in the 1820s. Many vertebrate species are known to have disappeared from these catchments but reliable data for species diversity, distribution, abundance and conservation status are not available. For this assessment of the diversity and status of the vertebrate fauna in these catchment areas a comprehensive database of vertebrate records was established, species distributions mapped, faunal communities determined by pattern analysis and conservation status determined at a regional level. The extent of post-European human-induced landscape change was evaluated by assessing the degree of habitat loss, loss of landscape function and resilience through changes to the water cycle, soil and energy flow and the impact of invasive species, diseases and agricultural pollution.Of the 595 vertebrate species verified for these catchments, 6% are introduced, 12% have been listed in NSW under the Threatened Species Conservation Act 1995, 4% by the Commonwealth Environment Protection and Biodiversity Conservation Act 1999, 40% are regionally vulnerable, 20% regionally endangered and 2% likely to have become extinct in the region. Overall we estimate that 64% (382) of species are declining. These statistics present a grim picture of the survival of vertebrates in these catchments and potentially for the sheep-wheat belt of eastern Australia. The extreme loss of habitat and its poor condition across much of these catchments followed by serious changes to the functioning of the landscape provide clear reasons for the catastrophic decline of vertebrates in this landscape. If this serious decline in the Central West and Lachlan catchments is to be halted, strategies aimed at habitat and landscape restoration must be developed. Current strategies based on Threatened Species management plans and ad hoc planting for revegetation have not produced results. We need a radical rethink.