Corop, Victoria, Australia: Information about Corop community for visitors and locals

Frogs of the Corop lakes

Some facts and observations

Written in 2001 by Jane Furphy and Marc Bellette, who together have both an interest in and knowledge of the flora and fauna of the Corop area, having both done extensive studies in Outdoor Education.

Over the last few years we have read a few frog books, pinned down a couple of frog folk and generally inquired into what we should expect to find by way of “froggy friends” in our area. There are apparently 7 main species in the Northern Plains. Last summer, with the help of some frog call tapes, we identified 6 of these in the recycling dam on the farm that we call ‘the swamp’.

General knowledge suggests that the local amphibians should be fairly quiet at this time of year. Despite this we heard two species (the Common Froglet and the Spotted Marsh Frog) on a recent walk down to the recycling dam. Over the next few months the frogs will become increasingly active and vocal — the following is some notes on what to look and listen out for.

Common Froglet

The Common Froglet repeats a creaking chirp — “crick, crick, crick”. It is a very common sound – not unlike a cricket but lower in pitch. Common Froglets are only 1.5cm long — you tend to see them hopping, in large numbers, especially across the roads at night after summer rain. We have also noticed them at the edge of grassy puddles or in channels.

Plains Froglet

The Plains Froglet is very similar in appearance and size to the Common Froglet — to distinguish between the two species with complete certainty you really need to hear the call. We don’t hear it so much at our place and it isn’t calling at the moment. It makes a longer, harsher, squelching “eeeek” sound that has a questioning inflection. While frogs in general are said to be declining in number the froglets appear unaffected or even to have benefited from agriculture.

Spotted Marsh Frog

The Spotted Marsh Frog is around 2–2.5cm long. It is a handsome creature in the field guide, but we have never managed to find one in the flesh to kiss it and see what happens. This is because it calls from thick vegetation on the side of the dams or in the swamp water itself. At this time of year it is rather a lonely sound — a staccato “kuk” — but in summer they can almost overwhelm you with their chorus. We call it the “cauldron, bubbling, cackling frog” — on mass the single notes take on the rhythm of a sparking fire, a spitting pot of pumpkin soup or of popping corn.

Barking Marsh Frog

It was with great excitement that we identified the call of the Barking Marsh Frog coming from the dense vegetation at the edge of the recycling dam last summer. As with all the froglets, it is difficult to distinguish the Marsh frogs by sight — the calls, however, are very different. As it name suggests, the Barking Marsh Frog sounds like a far distant bark of a dog — a soft and muffled “whrup”.

Peron’s Tree Frog

The frog that we have most often encountered in the flesh is the Peron’s Tree Frog. This one is about 3 or 4cm long and is readily identified by its cross-shaped pupils. Well into April they provided us, each evening, with a gruesome and spectacular moth hunting display on the sitting room window; dancing on the window they stalk and then tear apart the moths. During the day we find them sheltered in cracks in the wall, in flowerpots or in the milk cartons that we have used as tree guards. Their call is a long and drawn out “cra-ah-ah-ah-ah-ah-ah-ah-ah-ahhk” — a sound that has nicknamed it the “manical cackle frog”.

Pobblebonk

The Pobblebonk is the biggest frog that we have seen around about. It seems to get to about 5cm long. We have encountered one several times while digging in the vege garden or spreading we pea-straw bales where it seems to have buried itself. It produces a short, explosive, resonant and musical “bonk” and is very commonly heard in the summer.

Sadly, we have not as yet positively encountered the seventh of the supposed Northern Plains grassland frogs. It seems a pity that a frog named a “Growling Grass Frog” should make itself scarce, but it is one of the species that has markedly decreased in number over the last fifty or so years. This species survives by eating smaller frog species. It lets out a growl of about one second duration which it repeats every few seconds – one of my field guides writes it “crawark-crawark-crok-crok” and to my ear and we’ve heard it on tapes it sounds more like a rather miffed cat than an amphibian! It is possible that Marc has heard one in a cumbungi filled channel along the Wanalta-Corop Road or was it a feral cat?

Jane Furphy and Marc Bellette

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