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Breviceps gibbosus

The Cape rain frog

Kingdom: Animalia
Phylum: Chordata
Class: Amphibia
Order: Anura
Family: Microhylidae
Genus: Breviceps

Also known as: The Giant rain frog, the blassop or blaasoppie, which is Afrikaans for "blow-up", puffer or inflatable.
Short-headed frog, headless frog, hunched toad, cape short-head, South African rain frog, verruculose short-headed frog, Linnaeus' short-headed frog, Linnaeus' rainfrog, Blaasop, Jan Blom and South African short-headed frog.

Previously known as: Rana gibbosa, Bufo gibbosus, Rana breviceps, Bombinator gibbosus, Engystoma gibbosa, Engystoma dorsatum, Systoma gibbosum and Systoma breviceps.

Apparently it was first named Rana gibbosa by Linnaeus himself in 1758

I have fond memories of this unusual frog, from a suburban garden in Cape Town. On rainy winter nights, the familiar call of these nocturnally noisy amphibians would blend soothingly with the wind and rain. And keep visitors who weren't used to it awake all night.

Sadly, in urban areas, these animals are in decline. The suburban gardens superimposed on their habitat locks them up into tiny islands bounded by walls and foundations, tarmac and cars. Or they have unfortunate encounters with a garden spade. Fortunately they are also found outside of the urban areas, as far north as Citrusdal.

The species is endemic to the South-western part of the Western Cape province. It is classified as "Vulnerable", mostly due to habitat loss in Cape Town's urban sprawl and surrounding farmland.

These frogs are not aquatic or even amphibian. They spend their life on land, particularly in sandy areas. During the wet winters it will roam the undergrowth, feasting on snails and insects, or burrow in the soft earth. In the hot dry summers they will burrow deeper into the ground for shelter, or aestivate under rocks

They are easy to hear, since they ribbit loud and long when moistened. A good garden watering can sometimes start them chorusing. Yet they are maddeningly hard to find, since the noise is non-directional, and ceases abruptly when you come too close. Sometime, though we did find them under rocks.

The frog itself is no beauty queen. Squat, with a baggy body covered in mottled, clammy, rough grey skin. No discernible neck. It looks something like a overcooked baked potato with stubby clawed legs at the corners. The legs don't even lift the body off the ground and it doesn't move quickly. The beady eyes glare out from under the frowning forehead. The frog is 4.5cm long, (1.8 inches), small enough to fit into the hand, and the males are only a fifth of the size of the females.

Yet the frog is not defenceless. Its first defence mechanism, as the name "blassop" suggests, is to inflate itself and appear larger.

The frog may not be officially venomous or toxic, but is definitely unpalatable. I once saw a cat try to prey on one. After biting, the poor moggie spent the next while with its mouth open, drooling heavily and looking distinctly unhappy. He never went near those frogs again.

The mechanics of froggy sex on dry land are not that well studied, but the mating calls indicate that there's a lot of it going on. The males ribbit from the undergrowth. Too small to grab his mate when she answers his call, he glues himself to her with a sticky substance from his belly. The female digs a burrow, and eggs are laid not in water, but into this burrow, in their own pool of slime. The eggs mature rapidly into froglets. There is no water-breathing tadpole stage.


One particular rainy ribbiting winter's evening, I was eating strawberries and surfing the internet. I needed a login name for the new geek news site, slashdot. The rest is history.

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