Frogs and Reptiles of the Murray–Darling Basin

A Guide to Their Identification, Ecology and Conservation

Michael Swan

• Publisher: CSIRO PUBLISHING
• Year: 2020
• Print ISBN: 9781486311323
• eBook ISBN: 9781486311347
• Topic: Biological Sciences
• Subtopic: Biology
• Index: Biological Sciences

The Murray–Darling Basin spans more than 1 million square kilometres across the lower third of Queensland, most of New South Wales, the Australian Capital Territory, northern Victoria and the south-eastern corner of South Australia. Wildlife habitats range from the floodplains of the Basin to alpine areas, making the region of special ecological and environmental interest.

This book is the first comprehensive guide to the 310 species of frogs and reptiles living in the Murray–Darling Basin. An overview of each of the 22 catchment areas introduces the unique and varied climates, topography, vegetation and fauna. Comprehensive species accounts include diagnostic features, conservation ratings, photographs and distribution maps for all frogs, freshwater turtles, lizards and snakes recorded in this important region.

Certificate of Commendation, The Royal Zoological Society of NSW 2020 Whitley Awards: Field Guide

Lizards

Australia has a diverse lizard fauna and the northern regions, along with the central and western deserts, have the highest species diversity and richest lizard habitats of anywhere in the world. Each family of Australian lizards is represented in the Murray–Darling Basin.

They vary in size and appearance from the tiny Common Dwarf Skink (Menetia greyii) to the large and powerful, Lace Monitor (Varanus varius). Some lizard species in the MDB are threatened for various reasons. The direct disturbance or reduction in habitat through livestock grazing and agriculture is the main threatening process in some areas. Feral animals, particularly foxes and cats, are well known for preying on lizards and the effects of fire frequency, intensity and extent are an important factor in reptile conservation.

In the Victorian mallee of the southern Murray–Darling Basin, ‘management’ or ‘fuel reduction’ fires appear to have resulted in declines of the Mallee Tree Dragon (Amphibolurus norrisi). Based on pitfall trapping data, there are reports of a serious decline in this species from former habitat, with a concomitant increase in the Nobbi Dragon (Diporiphora nobbi), particularly in the southern Big Desert. It is unknown what impact this type of controlled burning has on the habitat of species with very disjunct distributions such as the Heath Monitor (Varanus rosenbergi). The clearing of woodlands for firewood, particularly River Red Gums, will have serious implications for the Lace Monitor (Varanus varius) that has a large home range and is dependent on old growth hollows for shelter and termite mounds for egg incubation.

Some lizard species that occur in native grasslands have declined as their native grassland habitat is systematically destroyed. Natural temperate grasslands are considered to be one of the most threatened Australian ecosystems. The Grassland Earless Dragon (Tympanocryptis pinguicolla) from southern Victoria has not been sighted since 1969. Presently, the earless dragon that occurs near Canberra is assigned to this species, but will shortly be divided up into several other species. Unless a near-miraculous rediscovery is made during current surveys for this lizard, the southern Victorian species may soon be declared extinct, which would be the first extinction of a reptile on the Australian mainland since white settlement. With the ongoing reduction of temperate grasslands in southern Victoria, similar habitat in the southern MDB will become even more important to species such as the Striped Legless Lizard (Delma impar).

In the northern Murray–Darling Basin, the Condamine Earless Dragon (Tympanocryptis condaminensis) is now restricted to reduced grassland roadside verges and farmed areas. The Roma Earless Dragon (Tympanocryptis wilsoni) is classed as Vulnerable as it is known only from a small area of grassland, just west of Roma. Continued clearing of native vegetation in the Southern Brigalow Belt remains the greatest threat to reptiles in that region.

Through the alpine regions of the Murray–Darling Basin, feral animals, particularly horses and deer, pose a threat to a variety of reptiles, due to destruction and degradation of habitat.

Endangered skink species such as the Alpine She-oak Skink (Cyclodomorphus praealtus), Guthega Skink (Liopholis guthega) and Alpine Bog Skink (Pseudemoia cryodroma) are directly affected. The Guthega Skink appears far more vulnerable to threatening processes because it is more specialised and not as wide-ranging as the Alpine She-oak Skink. The Arthur Rylah Institute and Zoos Victoria have collaborated on a wild monitoring and captive breeding program to learn more about the behaviour, diet and reproduction of these two species.

The MDB still has some good areas of intact River Red Gum, Belah woodlands and mallee woodlands with spinifex that support numerous lizard species. These important habitats require careful, ongoing management, effective control of threatening processes and grazing, hydrological and fire regimes that are much better informed by the knowledge generated by conservation science.

The following lizard species are found in the region:

• Carphodactylidae (southern padless geckos): 5 species

• Diplodactylidae (diplodactylid geckos): 23 species

• Gekkonidae (cosmopolitan geckos): 7 species

• Pygopodidae (flap-footed Lizards): 15 species

• Scincidae (skinks): 104 species

• Agamidae (dragons): 21 species

• Varanidae (monitors/goannas): 5 species

Nobbi Dragon (Diporiphora nobbi). Photo: M. G. Swan

Alpine She-oak Skink (Cyclodomorphus praealtus). Photo: N. Clemann

Guthega Skink (Liopholis guthega). Photo: M. G. Swan

Grassland Earless Dragon (Tympanocryptis pinguicolla). Photo: S. Mahony

Lace Monitor (Varanus varius). Photo: M. G. Swan

Southern padless geckos (Family Carphodactylidae)

This group is the only endemic family of geckos in Australia. They are widespread with ~30 sp...

Table of contents

• Cover
• Title
• Copyright
• Contents
• Preface
• Acknowledgements
• Introduction
• Frog
• Freshwater_Turtles
• Lizards
• Snakes
• Table
• Glossary
• References
• Index of common names
• Index of scientific names