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)

Perons Tree Frog (Litoria peronii) Tadpole Adaptations

Many people aren’t aware of the spectacular array of adaptations each frog species has to suit a particular niche. Furthermore, the adaptions of the larvae of particular frog species is even more overlooked. The Perons tree frog (Litoria peronii) is a common hylid frog which can be found abundantly in particular areas across eastern NSW. They are one of the few frogs which may be found in urban areas of Sydney. They are able to utilise habitats other frogs may not be able to use. Habitats such as water lily pots and water features with otherwise vertical bank angles can be successful breeding sites for Perons tree frogs with a few interesting adaptations.

The adaptations for this lifestyle include:

  • Suction pads on fingers which enables them to climb really well, even as a metamorph, enabling them to climb vertical surfaces as they have just turned into a frog.
  • Highly keratinised jaw sheath of tadpoles which enables them to eat floating vegetation (most other species tadpoles are only able to eat algae and detritus).
  • A very strong tail which can be utilised in a whirlpool motion to stay vertical in the water column. This enables them to stay anchored while eating floating vegetation.

I have a video of an example of Perons tree frog tadpoles exhibiting the whirlpool tail action (see below).

 

 

Next time you see a tadpole, observe them and see if they have any peculiar habits. Some are bottom feeders, some are flowing stream specialist and others show brilliant camouflage!

The Search for the Green Tree Frog

The Australian green tree frog would have to be one of Australias most iconic frog species. It is large and very docile, making it a popular pet around the world. it is spread across Australia, with a southern limit of around Wollongong, right up to Cape York, and has a wide distribution in semi-arid western areas. It is very common to encounter within most of their distribution, everywhere except for developed areas, especially Sydney. We have seen a drastic decline of these otherwise common amphibians within the last decade. So in this species of the week we will cover the general ecology of the green tree frog but also send out a message of suspected reasons why they may be declining and to encourage people to look out for these beautiful frogs.

The green tree frog has some interesting ecological traits. One of the most interesting is that they are sporadic callers and males will mainly only call in response to thunder and will chorus really heavily the following day after a thunder storm. Their preferred breeding habitat is ephermal (temporary) pools, that collect after heavy rain, but will also breed in more permanent water bodies as long as they are still (not flowing i.e. a river). The terrestrial habitat they prefer is open woodland; not to dense, but still have a canopy to take refuge in.

 

Green Tree Frog (Litoria caerulea) caught at Gloucester | Copyright Chad Beranek (2013)

Green Tree Frog (Litoria caerulea) caught at Gloucester | Copyright Chad Beranek (2013)

 

After asking around a lot, it seems these frogs use to be all over Sydney. The question is, why are they gone? Some obvious reasons are habitat clearance due to development, which removes the suitable habitat trees they shelter in, and you could also hypothesise that due to their docile nature, they would be susceptible to predation and attacks by cats. Another idea put forward (By Aaron Payne, Personal Communication 2014), is that the breeding habitat that they use is being removed in urban areas due to curb and guttering. This drains and removes all the temporary pools that collect consequentially removing the preferred breeding habitat of the green tree frog.

 

Green Tree Frog | Copyright Chad Beranek (2013)

Green Tree Frog | Copyright Chad Beranek (2013)

 

 

This is a real issue as it would be very upsetting to loose these iconic frogs from Sydney. Recently I have been focusing on trying to find a population in the Sutherland Shire region. After asking around a lot and checking the records, the last populations people have seen were in 2001 around the Jannali area and also right near Sutherland Hospital. There has also been reports of green tree frogs coming from up north which have started breeding but die off in the winter. To tell the difference between a green tree frog from the north and the south; the southern green tree frogs will only have green and white coloration, where the northern green tree frogs will have green and yellow coloration.

See Aaron Payne (c) Photos:

Southern

Green Tree Frog (Litoria caerulea)

Northern

Green Tree Frog (Litoria caerulea)

 

And one last note, the last green tree frog that has been seen and reported in the urban areas of Sutherland Shire (excluding the Royal National Park) was this one found in Kirrawee last year (see link below, Aaron Payne (c)), right near the brick pit (which is now also being developed). If you are a Sutherland Shire resident and have seen this frog anywhere within the Sutherland Shire, please let me know ASAP. I am really looking hard for these guys as I would like them to persist and would they be a lovely asset of beautiful fauna to preserve within Sydney and the Sutherland Shire.

Green Tree Frog (Litoria caerulea)

 

With a collective body of knowledge from all interested residents we may be able to locate them and preserve them, then hopefully ensure they become more abundant.

If you have had any recent sightings of the Green Tree Frog please contact me: gumnutnaturalist@gmail.com