When you are stuck knee-deep in a crocodile-infested bog —your way lit only by the twinkling of the Milky Way and the black night filled with a cacophony of croaking, singing, snoring and bonking toads — it is easy to be swamped by three paradoxical impulses: lust, loathing and learning.
Only when your guide begins to describe the natural history of these amazing amphibians do you realise that frogs, probably because they are so omnipresent yet furtive throughout much of our sleeping lives, have always activated such powerful passions in the psyche of human beings.
Which is probably why, instead of going on game drives and clicking away at elephants and lions, travellers to South Africa’s wilderness are increasingly choosing to spend hours exploring the murky world of toads. Another reason is the mischevious humour of Vincent Carruthers, one of the country’s experts on the taxonomy and behaviour of frogs.
Lust is the emotion Carruthers uses to best effect on this guided tour through the wetlands created by the Umkuze river in northern KwaZulu-Natal. “Faithless as most women,” he explains. “This one leaves her partner, takes a rest and rehydrates in the water below, and then climbs back into the nest to perform amplexus with another male.”
He is explaining the sexual behaviour of the foam nest frog, the species responsible for balls of white foam that you see suspended on branches hanging over water in the bush. The female secretes a fluid which is churned into a froth by the flolicking movements of the mating pair. Other males jostle into position close to female and join in the frenzy. After about 15 minutes she releases her first batch of eggs. The orgiastic males churn them into the foam and, along with the mating partner, ejaculate over them.
“The process,” says Carruthers gravely, “can last all night.” Many hours later, after a long rest, the female returns to the nest and adds more foam to the outside of her lair. This hardens into a crust and protects the eggs from predators.
Bushveld rain frogs are so passionate they literally become inseparable, glued together during amplexus, till the female decides to release a solvent that separates them.
Then there’s the knocking sand frog, found, not in the northern parts of KwaZulu-Natal, but in the dry western parts of the country. It is related to bullfrogs that spend almost every day of the year hibernating under the ground, emerging to spend just a day or two in a spasm of sex, before going back underground. “The name comes from their mating calls, which sound like planks knocking together,” Carruthers insists.
Loathing, always induced by toads, is an emotion enhanced when Carruthers and his colleagues scan the swamp for the red eyes of crocodiles before inviting their guests into the water to search for the painted reed frogs, bubbling kassinas, banded rubber frogs … and snoring puddle frogs, all of whom are making themselves heard but not seen on this dark night.
Carruthers explains that the terms “frog” and “toad” originated in medieval England, when they were applied loosely to a range of amphibian mammals. The only reason for using one rather than the other appears to have been whether the animal was likeable or loathsome.
Today the term “frog” applies to all families of the species, while “toad” is reserved for members of the Bufonid family of frogs, distinguishable by large glands behind their eyes that are mistakenly taken for warts.
There are species that emit toxic substances from their glands, warns Carruthers. banded rubber frogs, desert rain frogs (known as melk paddas because of the white cream they emit) and platannas (named for their flat-looking hands) protect themselves from predators by excreting poisons. “That is why dogs often froth at the mouth by mouthing a toad. But none of them can bite and the loathing of them is generally not earned.”
Learning, closely related to the chemical make-up of frogs, is perhaps the least explored of the primal urges that frogs induce in humans. Despite their toxicity, many species have great medicinal value. In the pharmacology of Zulu healers, burnt frogs are mixed with other herbs to effectively treat asthma and chronic oedema. Small quantities of toad-skin are are used to deal with irregular heartbeats.
Medieval healers also used frogs. A live frog in the mouth was believed to cure a sore throat. A swallowed live frog would solve any problems related to incontinence.
“Frog soup made from nine frogs was just the thing for whooping cough,” says Carruthers. “And the legs of frogs dangled around the neck healed scrofula.” Eye diseases could be cured if someone licked a frog and then the eye of the patient.
The learning impulse from frogs (and probably their lustful allure) lies behind one of South Africa’s great scientific discoveries. In the 1950s and 1960s local scientists discovered that if they injected a pregnant platanna with a sample of a pregnant woman’s urine, the frog would immediately release its eggs. Common platannas were thus bred in laboratories around the world and the “frog test” became the usual way in which women discovered whether they were pregnant.
If it’s a conventional safari rather the Freudian aspects of frogs that appeal, tourists should note Carruthers’s adage: “Frogging provides a purpose to go out into the wild, to study the starts and experience the night in the bush. And, more often than not, it is on one of these journeys that the best game viewing is to be had.”