Frogs

Frog biology and ecology

Litoria Chloris

Frogs are amphibians. The first stage of life is spent in water as eggs and tadpoles. The tadpoles transform into frogs and move onto land but the adults remain dependant on freshwater for breeding.

Adult frogs breathe through their skin, mouth cavity and lungs. Tadpoles have gills.

The soft permeable skin of a frog is important for gas and water exchange. Glands help keep the skin moist and some excrete toxins to deter predators.

Frogs are “cold-blooded”. They cannot conserve or generate their own body temperature. Therefore the body temperature of a frog changes with the surrounding environment.

Frogs will often shelter during the day under logs, stones, loose bark, in vegetation or by burrowing in the ground. Then come out at night to hunt their prey.

A frog’s diet consists mostly of insects and other arthropods but can include lizards, small mammals and other frogs.

We do not often notice frogs until it rains and when we hear a chorus of calling frogs. Rain and warmer temperatures are cues for most frogs to breed, although there are several winter breeders that occur in the Shire also. The chorus we hear are male frogs calling to females and warning off other males from their breeding territory.

Frogs in Byron Shire

Byron Shire is home to 28 species of native frogs including four listed as threatened in NSW.

This means Byron Shire has one of the highest diversity of frogs in any one place in Australia.

Unfortunately, the Cane Toad, an introduced species which threatens native biodiversity, has also established in the area.

Family	Scientific Name	Common Name	EPBC Act
Myobatrachidae	Adelotus brevis	Tusked Frog
Myobatrachidae	Assa darlingtoni	Pouched Frog	Threatened
Myobatrachidae	Crinia signifera	Common Eastern Froglet
Myobatrachidae	Crinia tinnula	Wallum Froglet	Threatened
Myobatrachidae	Lechriodus fletcheri	Fletcher’s Frog
Myobatrachidae	Limnodynastes ornatus	Ornate Burrowing Frog
Myobatrachidae	Limnodynastes peronii	Brown-striped Frog
Myobatrachidae	Limnodynastes terraereginae	Northern Banjo Frog
Myobatrachidae	Limnodynastes tasmaniensis	Spotted Grass Frog
Myobatrachidae	Mixophyes fasciolatus	Great Barred Frog
Myobatrachidae	Philoria loveridgei	Loveridge’s Frog	Threatened
Myobatrachidae	Pseudophryne coriacea	Red-backed Toadlet
Myobatrachidae	Uperoleia fusca	Dusky Toadlet
Hylidae	Litoria caerulea	Green Tree Frog
Hylidae	Litoria chloris	Red-eyed Tree Frog
Hylidae	Litoria dentata	Bleating Tree Frog
Hylidae	Litoria fallax	Eastern Dwarf Tree Frog
Hylidae	Litoria freycineti	Freycinet's Frog
Hylidae	Litoria gracilenta	Dainty Green Tree Frog
Hylidae	Litoria latopalmata	Broad-palmed Frog
Hylidae	Litoria lesueuri	Lesueur’s Frog
Hylidae	Litoria nasuta	Rocket Frog
Hylidae	Litoria olongburensis	Wallum Sedge Frog	Threatened
Hylidae	Litoria pearsoniana	Pearson's Tree Frog
Hylidae	Litoria peronii	Peron’s Tree Frog
Hylidae	Litoria revelata	Whirring Tree Frog
Hylidae	Litoria tyleri	Tyler’s Tree Frog
Hylidae	Litoria verreauxii verreauxii	Verreaux’s Frog
Bufonidae	Bufo marinus	Cane Toad *

* introduced species

Threats to frog survival include:

Litoria olongburensis

Anthropogenic climate change, drought and increased temperatures

Infection by amphibian chytrid fungus.

Destruction and degradation of coastal wetlands as a result of roadworks, coastal developments and sandmining.

Degradation of habitat due to changes in hydrological regimes and water quality e.g. modification to acidity and filling of wetlands and trampling by domestic stock.

Risk of local extinction due to small, scattered populations.

Isolation of populations through clearing and forest fragmentation.

Reduction of moisture levels resulting from road-works, logging, and too frequent burning associated with grazing.

Competition and predation by invasive species such as the cane toad

Pollution

Look after our local frogs

Lymnodynastes terrareginae

Protect and enhance frog habitat where you live. Some tips on how are available from the NPWS, How to create your own frog habitat, and from the Frog and Tadpole Study Group of NSW Inc.

A major factor in the decline of frog populations is the spread of an infectious disease - Chytrid fungus. Frogs may contract the disease by direct contact with infected frogs or tadpoles or infected water. For this reason it is very important to observe a strict hygiene protocol around frog habitats.

NSW National Parks and Wildlife Service recommend:

Only touch frogs when absolutely necessary and if doing so use disposable gloves, plastic bags and sterile equipment.
Clean and dry all equipment and wet or muddy footwear before and between visiting frog sites. This may include cleaning the tyres of your vehicle before visiting known high-risk sites where threatened frog species may live.
Never move a frog from one area to another.

See the NPWS website for more information http://www.nationalparks.nsw.gov.au/npws.nsf/Content/Frog+Chytrid+fungus

References

Byron Flora and Fauna Study 1999: A Report Prepared for Byron Shire Council
Anstis, M. 2002. Tadpoles of South-eastern Australia. Reed New Holland: Sydney.
Barker, J., G.C. Grigg and M.J. Tyler. 1995. A Field Guide to Australian Frogs. Surrey Beatty & Sons: Chipping Norton.
Cogger, H.G. 2000. Reptiles and amphibians of Australia. Reed Books: Sydney.
Robinson, M. 2004. A Field Guide to Frogs of Australia: From Port Augusta to Fraser Island including Tasmania. Australian Museum/Reed New Holland: Sydney.