Amphibian means 'two lives'. Most amphibians are charactised by a distinctive aquatic larval stage called the tadpole. These tadpoles metamorphose into the adult form and then usually leave the water in which they developed. Typically, tadpoles develop in fresh water, and amphibians in general have a low tolerance of saline conditions.
This docile frog is one of the biggest frogs (up to 10cm), and although found in many types of habitat, it is usually found around human habitation in mailboxes, meter boxes, downpipes, bathrooms and toilets. In their natural environment they hide in hollow tree limbs and rock crevices.
I evicted this frog from the toilet at my parent's house and found him a nice damp spot by the 'frog pond', but surprise, surprise, he found his way back to the toilet.
Green Tree Frogs, Litoria caerulea, are nocturnal and will emerge from their daytime sleeping hide after dark to feed on insects. It will take anything that fits into its gaping mouth, often shoving it in with its hands. Occasionally I find one on my back porch taking advantage of insects attracted to the outside light.
As well as calling to attract a mate during spring and summer, Green Tree Frogs call at other times, especially during or after rain. Its native predators are snakes, lizards and birds.
Frogs' eyesight and hearing
Frogs need good eyesight as they usually only eat prey that is alive and moving, therefore they generally have large, bulging eyes. They are located on top of the head to allow a wide field of view. As frogs are nocturnal, their night vision is generally well developed.
A frog can protect its eyes with a transparent 'eye-lid' called a nictitating membrane. This transparent membrane permits the frog to see underwater.
The transparent eye membrane
The tympanum (eardrum) behind the eye
Unfortunately, I don't hear the call of the Green Tree Frog in the Hunter Valley as frequently or in such numbers as when I was a child. Populations are thought to be declining due to habitat modification (land clearing, introduction of invasive weeds, filling of ditches and drains), and pollution.
The thin, porous skin of frogs and tadpoles makes them sensitive creatures. Through this skin, they absorb chemicals from the air and water, therefore, in areas where water or air pollution has occurred, the local frog community will be affected and there are likely to be very few frogs.
Well, come on in - no need to knock
Frogs will need help and consideration from all of us (industry and residential) if they are to thrive as they should.
The night-time frog chorus of several frog species in the paddock adjoining our house-yard following prolonged periods of rain over summer in the Hunter Valley, is an encouraging sound indeed.