Western Banjo Frog, Limnodynastes dorsalis

The best known burrowing frog. Once heard, never forgotten.

It doesn't matter if you are tone deaf or even hard of hearing as the 'bonk' - 'bonk' banjo like call is difficult to confuse with anything else. And if in their territory you have reasonable pools of water, you will hear it just about every night. I even had one hopeful banjo frog who had found a sunken plastic container full of water for the birds, he bonked loudly for over three weeks trying to attract a lady to his little paradise. But it was to no avail, being over 100 metres from an actual swamp, the banjo ladies were not taken in by calls of love from a dry sandy area. Eventually the frog gave up and presumably joined the competition at the swamp.

So you hear the call and say to yourself, I know that - it’s a western banjo frog, so you go looking for it. Now your troubles really start as tracking the actual frog from their calls is no easy thing to do, and most times given up in frustration, even when you know it is within a metre or two. Most frogs are very well camouflaged and their calls deceptive, particularly relating to distance from you. This is often made even more difficult when several frogs are calling from the same area. Fortunately they are quite distinctive when seen, so I just go looking and usually find them when they are moving around.

Western Banjo Frog, Limnodynastes dorsalis

I often think of the banjo frog as a bandit, just take note the distinctive mask-like eye patch that is underlined by a glandular white stripe, next note the bulge (oval gland) on each thigh. Despite other marking variations, these features are common to all of these frogs. Also with most of these banjo frogs there is a strongly marked pale stripe running down their back and the groin is usually crimson. The above distinctive features make it difficult to confuse it with other species, particularly when it is also the only Limnodynastes species in southern WA.

A bandit-looking western banjo frog - also note the raised thigh glands

Frogs from the genus Limnodynastes occur in areas where water can collect in deepish pools and therefore tend to be more common in the higher rainfall regions of eastern and northern Australia. These frogs differ from other frogs by constructing floating rafts of foam, into which the eggs are laid and fertilised. Once the tadpoles hatch they fall through to the water below. In my district there is little permanent water, but due to the dominant winter rainfall, many ephemeral swamps usually fill with water to provide suitable breeding habitat. Although frogs will move from one swamp to another, they are seldom found far from these areas. During long hot dry periods they will dig a burrow and await the winter rains.

"I don't think he saw me"

The range of coloration and markings amongst frogs of the same species is often remarkable, even within a small area. I have written about this before in relation to the Slender Tree Frog, Litoria adelaidensis 07. Frog colouration where there was a distinct correlation between the frog markings/coloration and habitat. Interestingly, the same thing seems to occur with the Western Banjo Frog. In the all these photographs, please note not only the coloration of the frog, but the habitat background, they are remarkably similar.

Probably the most extreme color variation of the banjo frog, but look at the sandy background

At the other extreme, these banjo frogs do not get much darker

The range of the Western Banjo Frog is just a little larger than the WA Wheatbelt zone, extending from the Murchison River (500 km north of Perth) to around 200 km east of Esperance. However there are other Banjo Frogs in Australia, so their call is known far and wide. The Eastern Banjo Frog, Limnodynastes dumerillii occurs from Adelaide to around Brisbane including most of Victoria and Tasmania. Then there is the Giant Banjo Frog, Limnodynastes interioris that inhabits central NSW and northern Victoria. And lastly the Northern Banjo Frog, Limnodynastes terraereginae that occurs from central NSW to the top of Cape York Peninsula. So if you like the sound of the banjo, there is plenty to keep you amused. Another name for this frog is Pobblebonk.

Western Banjo Frog, Limnodynastes dorsalis

Frogs are very reliant on suitable habitat and if that habitat is destroyed or altered, the frogs are often the first to suffer. Even if you have many frogs, if they are of the same species then you should be looking at providing greater diversity of habitat so other species can find a place too. Attracting frogs to your garden is much like attracting birds; it can be an absorbing hobby to see how many species you can accommodate. But it is important not to collect frogs from one area and introduce them to another, as a serious frog fungal disease can also be introduced by this means that can devastate frog populations and even kill entire species. So if you provide the habitat, they will move in of their own accord, where hopefully they can then build their numbers to spread to other suitable areas. This is a terrific way of being eco-friendly.

"Us frogs are really very friendly, plus we eat all the things you don't like"

Litoria cyclorhyncha, one big happy frog.

The Spotted-thighed Frog is friendly and always ready for a goodtime.

In an earlier post I featured the Moaning Frog "8. How did the Moaning Frog get its name?

http://natureitems.blogspot.com/2006/11/how-did-moaning-frog-get-its-name.html and illustrated the pitfalls of their stressful life. However with the Spotted-thighed Frog, the situation is fortunately reversed.

This frog is one of the Tree-frogs, but is probably just as active on the ground. There are over sixty Litoria species in Australia, with close to twenty in WA, but most live in the wetter northern regions. Around Esperance we have two, the Slender Tree-frog (from an earlier blog) "7. Do frogs adapt their colouration?"

http://natureitems.blogspot.com/2006/10/do-frogs-adapt-their-colouration.html and this one, the Spotted-thighed Frog.

A relaxed handsome Spotted-thighed Frog.

The only other tree-frog from the genus Litoria in this part of the world, is the closely related Motorbike Frog, Litoria moorei, which is found exclusively to the west of Albany and around the wetter near coastal regions to Kalbarri (500 km north of Perth). They look identical, except the Motorbike Frog does not have the spots on the thighs like the southeastern Spotted-thighed Frog.

When the frog is sitting normally the spots usually cannot be seen, but when swimming they are obvious and contrast brightly against the black inside leg color (another feature of this frog).

The spotted-thighed frog is not only friendly, but also quick to take advantage of anything that can make life more pleasant. I have had up to five frogs soaking up the water as if they were in a sauna.

Naturally intelligent and quick to take advantage of circumstances, they can do very well for themselves.

As the spotted-thighed frog requires open water to lay its eggs, it is generally found close to permanent, or at least seasonally flooded areas. However, it is very hardy and can tolerate prolonged dry periods by remaining hidden and inactive during periods of low humidity (frogs absorb water through their skin).

During the cooler wetter months, these tree-frogs remain active on most nights, with some seeking the limelight by being obnoxiously obvious. Nevertheless, nothing gets in the way of breeding and the following jolly call is common around swamps and waterholes during spring.

http://frogsaustralia.net.au/frogs/calls/qt/litoria_cyclorhyncha.mov
My thanks to the Australian Frog Database

These frogs will eat most invertebrates and the best hunting grounds tend to be closer to the ground, so it is at these lower levels they are more commonly found.

Spotted-thighed Frog, Litoria cyclorhyncha

Nevertheless, when predators like snakes also share these lower elevations, finding a comfy spot on a Banksia speciosa flower high off the ground, is not a bad place to be, providing you keep a lookout for the dreaded Tawny Frogmouth.

It may astonish some people, but frogs can lead interesting and exciting lives, plus adapt surprisingly quickly to take advantage of any introductions to their local environment. Having several frog species means your local environment is varied and in good condition, as habitat diversity will attract numerous insects to eat and provide cool places to hide during the day. So why not brighten your day and make a friendly frog near you happy!

The amazing camouflage of Crinia georgiana

Not only can't you find them, but they also call like a duck!

I refer to a small frog called the Quacking Frog or Tschudi's Froglet, Crinia georgiana.

Does it really sound like a duck? Well listen here:

QuickTime: http://frogsaustralia.net.au/frogs/calls/qt/crinia_georgiana.mov
or
Windows Media: http://frogsaustralia.net.au/frogs/display.cfm?frog_id=6

(Recording compliments of Frogs Australia Networks)

The Quacking Frog grows to 4 cm in length (although usually around 3 cm) and is very common in shallow freshwater swamps and rocky outcrops from Esperance (600 km SSE of Perth), to Gingin (around 100 km north of Perth). During their breeding season (winter to early spring), their calls are deafening, but try and find one and you either have to be very good or very lucky.

In this photo there is an adult frog making up most of the frame. Can you see it?

I dare say you could find it well enough after I had told you it was there, but if you were casually looking at the same area, most would not. Not only do the colors blend beautifully into the background, but also the body comprises many bumps, skin folds and wavy lines. This disguises the outline of the frog, providing an almost perfect camouflage.

Take the frog away from its natural environment and it has quite distinctive coloration. The red around the groin is typical to adults of both sexes, plus the golden patch on the upper eyelids (in some areas apparently, the eyelids can be red). These are the most distinctive recognition features.

Quacking Frog, Crinia georgiana

Just look at the bumps on this fellow!

And the skin folds and wavy lines on this one! That golden blotch on its flank can also be white.

This Quacking Frog is not impressed by being picked up, but you can see more clearly the golden patches above the eyes and the very granular belly.

So because frogs can't always be seen, to discover the secrets of your bush, you may have to visit in the evening (during the mating season) and just listen. Often there are so many calls from different species, it can be difficult to identify them all, but this is still the best way to ascertain the number of frog species in your area.

Frogs are not only very cute, but are also an important part of the ecosystem, so look after them by protecting their habitat. However do take the kids and enjoy the educational experience of frogging on a pleasant mild evening, only make sure you leave your discoveries where you find them.

How did the Moaning Frog get its name?

How did the Moaning Frog, Heleioporus eyrei, get its name?

For a start it has a very mournful call (hear it on this QuickTime link

http://frogsaustralia.net.au/frogs/calls/qt/heleioporus_eyrei.mov

from the Australian Frog Database), but is this the only reason?

I don't think so!

The Moaning Frog is very common along the southern and lower western coastal areas of Western Australia. It breeds in burrows each autumn that are located in shallow, usually seasonal, freshwater depressions, from which the male calls. From there they (including the young frogs) spread out into the neighbouring country where they daily burrow into the usually sandy soils to rest during the day and emerge at night to feed.

They are a chunky (over 60 mm in length), ground dwelling frog with large eyes and a larger tummy, both of which in my opinion aid in its cute but mournful appearance.

This is a typical Moaning Frog, look into its eye and tell me if it is not worrying whether it has left something on the stove!

This mournful expression starts very young.
This one (fresh out of the burrow) seems to be wondering if tonight will be its last.

And as for steps....... as far as this kid is concerned, it's the end of the world.

This one would have to be thinking "I'm doomed!"

Even in adult life, the depressed state of mind remains.

Some might say the Moaning Frog has a lot to contend with.

However, others learn to overcome their negative thoughts to become froggy tough-guys.

Moaning Frog, Heleioporus eyrei

Do frogs adapt their colouration?

Do frogs adapt their colouration to suit their habitat, or are there micro-evolutionary processes at work?

Some frog species are notorious for their colour variability, which often create identification problems. One such frog is the Slender Tree Frog, Litoria adelaidensis, which lives near freshwater in the SW and southern coastal region of Western Australia. It grows to around 45 mm in length, however most are usually smaller, particularly males.

Below is a typical Slender Tree Frog, note the slender body with a tapering head. Also the pronounced dark stripe, extending through the eye to the lower flanks, as these are the more obvious features for quick identification.

The extent of green markings along the sides is extremely variable, as are the browns along the back.

Slender Tree Frog, Litoria adelaidensis

This other Slender Tree Frog has no green makings.

Less often seen is the bright red/orange on the backs of the thighs.

And even less seen, is the underside of these frogs, showing the large disks, the unwebbed fingers, but strongly webbed toes.

Now check out the frog colors as they relate to habitat.

See how the bright green patches and dark colouration blend into this tree/shrub habitat.

Also how the all brown marking of this frog match the tree, in this case the Flat Top Yate, Eucalyptus occidentalis that is common in ephemeral swampy areas.

Note the green reed-like colouration running the length of the frog with no markings along the back. This frog was very common with other similarly marked individuals on the Jointed Twig Rush, Baumea articulata, whose presence denotes areas of prolonged near surface freshwater.

This frog is the greenest tree frog I have ever seen, it was living amongst low green sedges on the outer edge of an ephemeral swamp.

In the Esperance area, the above four very different colouration types would certainly assist the frogs survival within their preferred habitat. So is it something the frogs can influence, or is it a mini habitat variation, where variants are more easily spotted and eliminated by predators, thereby promoting compatible color forms within their micro-habitats?