Australias Ancient Amphibian

Thought to have over 100 million years of independent evolution, the Tusked Frog (Adelotus brevis) is one of Australia’s truly unique amphibians. At first glance you may think it is just like every other frog, however when paying closer attention to the morphology of this frog, there are a few interesting features which set it a part from all other frog species. The most obvious feature is the tusks, hence its name the Tusked Frog. This frog species has small (around 5 mm long) tusks within the mouth on the lower jaw. Males use these tusks for ritual combat and territorial interactions during mating season.

 

A small male Tusked Frog (Adelotus brevis) | Copyright Chad Beranek (2014)

A small male Tusked Frog (Adelotus brevis) | Copyright Chad Beranek (2014)

 

This photo below shows the remarkable ancient characteristic of this frog species and is why this frog is call the Tusked Frog.

Adelotus brevis - Tusked frog

 

Generally speaking, the larger the head of the male, the more successful the male will be in combat. Head size is an easy way to tell a part males from female. Males always have a disproportionately larger and ‘boofier’ head than females , who seem to have a disproportionately smaller head! Males are usually bigger than females reaching a maximum of 5 cm snout to vent length, where females reach a maximum of 4 cm.

Another interesting feature of the Tusked Frog is the marbled belly which can have white, black and red patterns. Each individual has a unique belly pattern, and this can be used to tell each individual a part from one another.

 

Belly colouration of a large male | Copyright Chad Beranek (2014)

Belly colouration of a large male | Copyright Chad Beranek (2014)

 

This photo emphasizes the ‘boofy’ head of the males:

Tusked Frog (Adelotus brevis) - Male

 

Breeding season for the Tusked Frog takes place from October – December within slow moving streams and ponds, usually associated with rainforest or wet sclerophyll forest. They occur along the east coast of Australia, from north of Sydney to about the middle of the Queensland coast. Although they are not classified as threatened in Australia, these frogs have been suffering declines, especially in the New England Tableland. Reasons for their decline in these areas are due to habitat degradation and plague minnow, hence it is always a relief to hear these guys in a water way!

These guys can be quite hard to locate as they dive bomb the water as soon as there is a disturbance. It is easier to listen for their unique double inflection call (see below). Next time you find yourself near rainforest waters, see if you can listen out for this call, and be blessed by the knowledge that you are listening to a very ancient amphibian!

 

 

 

Mining for Gold; Frogs of Quarries

Scattered around Sutherland Shire are small disused quarries. These sites echo with age from a hundred or more years ago when the generations before us were mining out shale and sandstone to build some of the very buildings we use today. During this mining extraction process, holes the the ground were created, cutting into the bed rock. The sandstone bed rock is impermeable and more often than not, these old mining spots become full of water as the mining works usually cut in a pond like shape into the earth.

As an indirect and unforeseen  consequence, these disused quarries have become perfect habitat for frogs. Some of them being large enough to sustain permanent wetlands and other smaller ones become equally as important ephemeral wetlands (A water body which dries up periodically). In fact, in this day and age, ephemeral water bodies may be especially important for frogs, as their periodic drying removes the water born fungal pathogen effecting frogs world wide called ‘chytrid’.

It’s not just frogs that are able to utilize these quarry wetlands. Water birds, snakes and freshwater macroinvertebrates are able to live and breed in these habitats. A good example of these habitats are the many sand mining quarries found along the stretch of Greenhills near Cronulla, which reach out patchily to Kurnell. There are many smaller disused quarries found scattered throughout the Royal National Park.

A few nights ago, I went to investigate how much diversity of frogs one of these artificially created wetlands harbor and I was astounded and very impressed to hear and see at least 9 species.

 

The Quarry

The Quarry

 

The first noise I heard as I approached the wetland was clicking of the Common Eastern Froglet (Crinia signifera) which you are likely to hear almost all year round in any pool of water, whether its a puddle or a wetland. The next noise I heard was unfamiliar to me at first. It sounded reminiscent of a ducks ‘quack’ but It sounded frog like to me. I followed my ears to locate one and It turned up being the Wallum Rocket Frog (Litoria freycineti). It was exciting to hear them calling in such numbers (around 20 at least) as they usually begin calling in November, so a few weeks early.

 

Wallum Rcoket Frog (Litoria freycineti) | Copyright Chad Beranek (2014)

Wallum Rcoket Frog (Litoria freycineti) | Copyright Chad Beranek (2014)

Wallum Rocket Frog (Litoria freycineti) | Chad Beranek (2014)

Wallum Rocket Frog (Litoria freycineti) | Chad Beranek (2014)

Common Eastern Froglet compared to a Wallum Rocket Frog

Common Eastern Froglet compared to a Wallum Rocket Frog

 

I did note that the water in this particular wetland was very warm and could be an explanation for the early arrival of the Wallum Rocket Frog. It could also explain the abundance of metamorphling frogs literally jumping every where. From tiny 5 mm Common Eastern Froglet metamorph, to larger Striped Marsh Frog metamorphs. In warm water the growth and development of the tadpole is spend up which is an adaptation to avoid being stuck in a water body that is destined to dry up.

 

Common Eastern Froglet (Crinia signifera) | Copyright Chad Beranek (2014)

Common Eastern Froglet (Crinia signifera) | Copyright Chad Beranek (2014)

Metamorph Common Eastern Froglet (Crinia signifera) | Copyright Chad Beranek (2014)

Metamorph Common Eastern Froglet (Crinia signifera) | Copyright Chad Beranek (2014)

 

 

The next noise that became apparent to me (which were also in very high abundance, approximately 30+ calling individuals), were the Smooth Toadlets (Uperoleia laevigata). These small frogs make a dull ‘arrrkkk’ sound, calling terrestrially, sometimes quite a distance from the water.

 

Smooth Toadlet calling from leaf litter | Copyright Chad Beranek (2014)

Smooth Toadlet calling from leaf litter | Copyright Chad Beranek (2014)

Smooth Toadlet (Uperoleia laevigata) | Chad Beranek (2014)

Smooth Toadlet (Uperoleia laevigata) | Chad Beranek (2014)

 

After listening carefully I started to tune into the frequencies of some tree frog species who were joining in on the chorus. Calling in much less abundances, the Perons Tree Frogs (Litoria peronii) maniacal cackle could be heard in numbers between 5-10, and also the occasional inclusion of Eastern Sedge Frogs (Litoria fallax), with about 5 individuals contributing.

 

Perons Tree Frog (Litoria peronii) | Copyright Chad Beranek (2014)

Perons Tree Frog (Litoria peronii) | Copyright Chad Beranek (2014)

Perons Tree Frog (Litoria Peronii) | Copyright Chad Beranek (2014)

Perons Tree Frog (Litoria Peronii) | Copyright Chad Beranek (2014)

Eastern Sedge Frog (Litoria fallax) | Copyright Chad Beranek (2014)

Eastern Sedge Frog (Litoria fallax) | Copyright Chad Beranek (2014)

Eastern Sedge Frog (Litoria fallax) | Copyright Chad Beranek (2014)

Eastern Sedge Frog (Litoria fallax) | Copyright Chad Beranek (2014)

 

I noticed huge amounts of tadpoles in the water. On closer inspection I could see multiple different species and the occasional dragonfly nymph (a common predator of tadpoles). However it seemed they were the only predator, with no appearances of fish. Perhaps this is a reason why tadpoles are in such high abundances here. I managed to scoop a large tadpole out which I thought could of been a Giant Burrowing Frog (Heleioporus australiacus) tadpole. However it was more likely to be a Striped Marsh Frog (Limnodynastes peronii) tadpole… Speaking of which where are the Striped Marsh Frogs?

 

Probably a Striped Marsh Frog tadpole | Copyright Chad Beranek (2014)

Probably a Striped Marsh Frog tadpole | Copyright Chad Beranek (2014)

 

After scanning deciding to head home I did a quick scan of the bank as I was exiting and stumbled across a frog I’m sure you are all familiar with, the Striped Marsh Frog (Limnodynastes peronii). How strange it was to hear not even one calling, and only see 2 this night. Perhaps they don’t fair as well in natural sites, and utilize urban areas better?

We have covered a frog fact Friday on this common frog and can read more about it here: http://gumnutnaturalist.com/frog-fact-friday-the-most-common-frog-of-sydney/

 

Striped Marsh Frog (Limnodynastes peronii) | Copyright Chad Beranek (2014)

Striped Marsh Frog (Limnodynastes peronii) | Copyright Chad Beranek (2014)

 

After getting ready to head back to the car, I stopped to have one last marvel at the chorus of multiple species of male frogs competing to find a mate. I took recordingg to share it with you. See if you can tease out which species of frogs are calling in the recording!

Recordings:

141011_003 141013_003

 

The Blue Mountains Stream Frog

Found near the tops of mountains in areas near Sydney, the blue mountains stream frog resides. This species of the week is on a locally uncommon frog which usually goes unnoticed with most attention being paid to the endangered frogs. The blue mountains stream frog inhabits sandstone creeks in high altitude areas where is it well adapted for this habitat. Areas it is found includes the Blue Mountains and Darkes Forest. It quite large for a frog has powerful and agile legs, perfect for jumping along rocky sandstone banks and swimming through fast flowing mountain creeks.

 

Blue Mountains Stream Frog (Litoria citropa) | Copyright Lucy Kidson (2014)

Blue Mountains Stream Frog (Litoria citropa) | Copyright Lucy Kidson (2014)

 

The blue mountains stream frog can be very varied in coloration, but will always have a red tinge under their arms and legs. Most of the time they are flanked by green (which can be almost fluro!) and have a brown top, with darker lines outlining their head. Some specimens can be almost completely green, but will maintain the head outline.

 

Blue Mountains Stream Frog | Copyright Lucy Kidson (2014)

Red coloration under the arms and legs | Copyright Lucy Kidson (2014)

Green morph of the Blue Mountains Stream Frog | Copyright Lucy Kidson (2014)

Green morph of the Blue Mountains Stream Frog | Copyright Lucy Kidson (2014)

 

They begin calling usually around the middle of September with the first onset of warm weather followed by rain. They have a very soft call which can be difficult to detect when there is wind and flowing water about. They have a soft call due to the absence of a voice box. Even though they are usually hard to hear, in contrary to most other frogs, they are much easier to find when you get a creek they are present in. From September to January, they will be found all over creeks in high altitudes, usually on the sandstone banks, but may occasionally be seen perched up on ferns and branches of shrubs. If you are lucky enough, you may find some in amplexus in small pools to the sides of the creek.

 

Litoria citropa in amplexus | Copyright Lucy Kidson (2014)

Litoria citropa in amplexus | Copyright Lucy Kidson (2014)

 

Blue Mountains Stream Frog (Litoria citropa) | Copyright Lucy Kidson (2014)

Blue Mountains Stream Frog in a fern | Copyright Lucy Kidson (2014)

 

And if you are especially lucky, you may even have one jump on your face!

 

Face frog

Face frog

King of the Sandstone Throne: The red crowned toadlet

This species of the week is dedicated to the threatened red crowned toadlet (Pseudophryne australis) which is both spectacularly adorable and has an incredibly interesting strategy of survival. This frog is quite small and is really strange for a frog in the way it lives. The red crowned toadlet, unlike most frogs, makes a terrestrial nest. The male will sit and guide his egg clutch and call almost all year round. Female red crowned toadlets visit the male and deposit eggs which he fertilises. The tadpoles start development inside the egg. A male will end up with eggs of many different stages of development stages. When it rains, the eggs in the nest will wash away to the closest puddle or creek where the developed tadpoles will emerge from their eggs to complete development as free swimming tadpole. Only the eggs at the right development stage will be able to survive when being washed into a puddle.  By having eggs of multiple development stages, the red crowned toadlet is able to ensure at least some of the eggs will be at the correct development stage when it rains and will hatch. This is the unique strategy of the red crowned toadlet known as ‘bet hedging’.

 

Copyright Chad Beranek (2014)

Copyright Chad Beranek (2014)

 

The red crowned toadlet is found in sandstone areas across Sydney and is quite well distributed within the Royal National Park. They prefer rocky sandstone outcrops and reside within tributaries that are prone to drying up. This is the perfect habitat for their unique life strategy. They are threatened due to being easily wiped out during development and may be susceptible to the changes to water run off due to curb and guttering, which diverts water away from the small tributaries that the red crowned toadlets live in.   With good management, this species can be preserved and hopefully they will continue to exist unimpeded in areas such as the Royal National Park as they are an interesting little frog.

 

A male Red Crowned Toadlet next to his nest of eggs | Copyright Lucy Kidson (2014)

A male Red Crowned Toadlet next to his nest of eggs | Copyright Lucy Kidson (2014)

 

One last random fact sure to interest most people is you can actually talk to them and they will call back. They are able to hear the frequency of the human voice, and if you yell for example “HEY FROG!?”, it will respond in its calls which is a series of squelches and squeaks.

 

Male Red Crowned Toadlet | Copyright Lucy Kidson (2014)

Male Red Crowned Toadlet | Copyright Lucy Kidson (2014)