Eastern sedge frog Litoria Fallax

If you will stay close to nature, to its simplicity, to the small things hardly noticeable, those things can unexpectedly become great and immeasurable ~ Rainer Maria Rilke

Most of us usually head to wilderness or wide open spaces to feel close to nature. We tend to regard urban spaces as human habitat, and indeed the urban landscape is designed almost exclusively with humans in mind. But one has only to look at a tiny weed poking through a pavement crack, or a little skink scuttling for cover between the rocks that edge our gardens, to realise that many other species are also prepared to call our human habitat home. In fact, suburban backyards and parks are teeming with life and in each future edition of Bush Hands we’ll be shining the spotlight on any one of the living treasures that could well be living in your backyard.

As a place to start I cast my eye around my own suburban garden. My gaze falls to a tiny pale brown frog, barely more than a centimetre long, sitting silently atop the fronds of a fishbone fern Nephrolepis cordifolia (yes, it's a weed – I have, after all, never claimed to be a good gardener) (image 1). Many coastal residents will be familiar with the high-pitched ‘cr-e-e-e-k’ or ‘cr-e-e-e-k pip’ of the eastern sedge frog Litoria fallax, and that is indeed the delightful little frog that is hiding among the fishbone ferns.

There are a number of physical features that distinguish the eastern sedge frog from superficially similar coastal species, including a dark band between the eye and nostril, a white jaw stripe and usually orange inner thighs as seen in the photo at right (image 2). However, the general body colour can vary widely from fawn to green and multiple combinations of those two colours, likely influenced by temperature and colour of surroundings. Occasionally unusual variations can occur, such as the frog to the right who was living in a shallow black-lined garden pond (image 3). Usually, however, colour variations shown in images 4 – 12 are more typical.

If you live near a pond or lake you have probably heard the cheerful chorus of males throughout spring and summer, which often intensifies before and after rain. During this time, competition between males for prime calling positions on vegetation can become intense and it is not unusual to see two males wrestling and jostling for occupation of the highest spot on emergent vegetation.

Female eastern sedge frogs lay their eggs in a series of small clusters, each containing up to 35 eggs. After 10 – 15 seconds the female will move to a new location and start the process again. Males cup their feet around each cluster to fertilise them after laying. Researchers have recorded females laying as many as nine clusters in the space of 28 minutes. Usually this process results in around 200-300 eggs in multiple clusters but can be result in as many as 1,300 from a single female. After fertilisation, the egg cluster will either adhere to vegetation or sink into the water, where they will hatch after three to five days.

Along with graceful tree frogs Litoria gracilenta, eastern sedge frogs frequently become accidental travellers huddled in banana bunches and other plants and produce. However, while this little frog might be one of our backyard treasures, its arrival in new areas can increase the risk of disease if they are released into other native frog populations.

Article and images by Julie O'Connor, SCC Senior Conservation Partnerships Officer.

References

Anstis, M. 2002. Tadpoles of South-eastern Australia, Reed New Holland, Sydney.

Robinson, M. 2002. A Field Guide to Frogs of Australia. Australian Museum/Reed New Holland, Sydney.