The Wet Tropics area is home to about 54 species of frogs. We couldn't possibly describe them all here, but there are some notable species featured below - some because of their size or jumping ability, while others have a particular fondness for suburban gardens and are easily found.
One of the world's favourite frogs is the common green tree frog (Litoria caerulea) which is called White's tree frog in the USA. Even as an adult of 90mm in size, the green tree frog always retains its gentle baby face. It is probably the most commonly kept frog in Australia. It is often found around houses, especially in outdoor toilets and drainpipes.
Sometimes these frogs are found in mailboxes and moved, only to be found in the same mailbox a few days later. Litoria caerulea actually has a homing instinct. Common green tree frogs are usually bright green with golden eyes, sometimes with white spots on their sides and back. Like all tree frogs, they have large flat discs on fingers and toes to help with climbing.
Some of the most impressive frogs are the white-lipped tree frogs (Litoria infrafrenata) which can reach over 130mm in length. In frogs, length is measured from the tip of the snout to the vent - the legs are not included.
White-lipped tree frogs are generally green, but can range in colour from pure green to greenish-brown or pale brown. They have a brilliant white stripe that runs along their lower jaw and the side of its head. When the males are ready to mate, the gold stripe on their thighs flushes a salmon-pink colour. The best places to see the white-lipped tree frog are paperbark (melaleuca) swamps and in leafy suburbs. They frequent houses and are often found associated with drainpipes. Their call sounds like a dog barking. This frog is sometimes accidentally dispatched to other states in boxes of bananas or other produce.
When driving along northern roads at night, there are spectacular jumpers that are frequently seen in your headlights. Both of these frogs can clear the width of a lane in each jump. Both are nearly the same size - more than 60mm for females and roughly 40mm for males (about the size of a matchbox). The brown striped one with the very pointed snout is called the striped rocket frog (Litoria nasuta). The other one is the northern stoney creek frog (Litoria jungguy) which is chocolate brown with a pointed snout and a very dark stripe through the eye that reaches just past the arm. Two other great jumpers along streams are the Australian wood frog (Rana daemeli) which jumps several metres into streams if disturbed; and the dwarf rocket frog (Litoria microbelos) which is the tiniest of the tree frogs (2cm) and makes quickfire jumps through lower vegetation more than a metre long.
The stoney creek frog also has vibrant black and yellow spotting on the back of its thighs. The males change their entire body colour to banana yellow when they are ready to mate! You can find the stony creek frog in just about any creek that has a rocky bottom, however, the striped rocket frog seems to have a preference for flooded roadsides and cane fields.
Another of the impressive rainforest frogs is a ground dweller which burrows under the soil. In tropical Queensland, this species complex has recently been split into three separate species: the northern barred frog (Mixophyes schevilli), the mottled barred frog (Mixophyes coggeri) and the Carbine barred frog (Mixophyes carbinensis). These are heavy set brown frogs with darker brown blotches on their back and face which helps it blend in with the leaf litter it hides in. Unlike most frogs, the pupil is hardly visible in the barred frog so the eye appears entirely dark. However, the juveniles have a crimson upper iris. The legs are heavily striped with dark bars, hence its common name, and the call is a deep, guttural 'wonk'. The barred frogs occurs from the coastal lowlands at sea level all the way up to the mountaintops and, aside from their impressive bulk and excellent jumping ability, they also have the distinction of producing Australia's largest and longest lived tadpoles. The high altitude species, Mixophyes carbinensis produce tadpoles which are 150mm long and which require two years to metamorph!
When there's been heavy rain and the cane fields become flooded, this is the time to find two of the ground-dwelling frogs: the ornate burrowing frog (Platyplectrum ornatum) and the marbled frog (Limnodynastes convexiusculus). The ornate burrowing frog is pale tan with darker spotting and often has a distinctive yellow stripe running down the centre of the back. It is about 40mm long and is a darker base colour with very dark spots and a pale grey, granite-like pattern on its sides. When the marbled frog is stressed, it flushes to almost black in colour. Both of these frogs with their stocky bodies and short legs can be seen sitting or floating in the water. The calls of both these frogs are quite soft and consist of a single, short note. The ornate burrowing frog call sounds like a tennis ball being hit. The marbled frog sounds like a child saying the word, 'unk!'.
There are some frogs that prefer a drier habitat. Visitors to the Townsville area or the western reaches of the Atherton Tableland might notice a very round frog with short feet that emerges from the ground only after heavy rains. This frog is called the superb collared frog (Cyclorana brevipes) and it has a yellow-beige background colour with broken brown stripes or blotches down its back. Water-holding frogs survive the dry months by encasing themselves in a 'plastic bag' made from their skin. They 'hibernate' in this bag until the heavy rains return. Once water reaches their bag (sending the signal that conditions above are good for breeding), they climb back to the surface, swallow the bag and breed quickly before the waters dry up again.