The Vertebrate Fauna of Northern Yengo National Park

Overview

Northern Yengo National Park comprises 46 000 hectares of a prominent dissected sandstone plateau on the southern escarpment of the Hunter Valley. It lies at the convergence of a number of environmental and climatic influences from the north, west and east and supports a highly diverse assemblage of fauna. There are at least 256 native terrestrial vertebrate fauna species known to use the reserve, of which 28 are listed as either vulnerable or endangered on the NSW Threatened Species Conservation Act (1995). There are ten species of introduced fauna recorded including the fox and wild dog. The faunal diversity is typical of large sandstone reserves in the Sydney Basin.

This report compiles and reviews background information on the fauna of northern Yengo NP. This has been supplemented by extensive data generated by surveys conducted during the spring-summer period in 2004-5, in order to provide a more accurate inventory of fauna across the range of habitats present. A total of 161 systematic sites were established to sample birds, frogs, bats, reptiles and arboreal mammals in the reserve. Terrestrial mammals have been sampled opportunistically, while fish have not been included in this study. These data can be further used for analysing habitat use, faunal assemblages, impact assessments and abundance estimates for species of interest.

Our findings confirm that northern Yengo National Park is characterised by the suite of birds, reptiles, frogs and mammals typical of hinterland sandstone environments of the Sydney Basin. A number of species that are endemic to the Sydney sandstone environments are present in the reserve, including the rockwarbler, large-eared pied bat, southern Leaf-tailed gecko and red-crowned toadlet. Northern Yengo National Park is surrounded by the open Hunter Valley to the north, the Wollombi Valley to the east and Howes Valley to the west. These areas are fertile, dry rainshadow valleys that prior to clearing supported a complex of grassy woodlands. These woodlands provided habitat for a range of fauna species typical of the central western slopes and plains. Due to extensive clearing over the last 200 years many of these species are now recognised as either endangered or vulnerable under state threatened species legislation. With their preferred habitat much reduced in area, these species are largely restricted to small remnants of dry woodland. This pattern is apparent in northern Yengo National Park with a number of bird species in particular occupying dry grassy woodland remnants and dry ironbark forests on the margins of the reserve, including the black-chinned honeyeater, grey-crowned babbler, diamond firetail, speckled warbler, turquoise parrot, brown treecreeper and regent honeyeater. Other species that occupy these habitats include the squirrel glider and barking owl.

Surveys revealed that northern Yengo National Park supports significant populations of several threatened species including the glossy black-cockatoo, large-eared pied bat, brush-tailed rock-wallaby, koala, eastern cave bat and yellow-bellied glider. In contrast, other threatened species were recorded more sporadically and are likely to have a patchy distribution or be in low numbers, including Rosenberg's goanna, squirrel glider, powerful owl, sooty owl and greater broad-nosed bat. Numbers of the threatened amphibians, the red-crowned toadlet and giant burrowing frog, are likely to have been underestimated in the reserve due to the drought of the last few years. The eastern pygmy-possum and spotted-tailed quoll remain poorly understood in the reserve, as intensive ground mammal surveys have not been implemented.

At present the largest threats to species within the park is from the impact of fire and feral predation and competition. The report concludes that the reservation status of several threatened species could be improved by directly targetting specific habitats for future acqusitions and voluntary conservation agreements. Proposed additions that include confirmed records and habitat for the suite of declining woodland birds, squirrel gliders, masked and barking owl and brush-tail rock-wallaby should be given high priority.


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Page last updated: 17 March 2014