Gerald Durrell - THREE SINGLES TO ADVENTURE

"You remember those small greenish frogs we caught at Adventure? Those ones about the size of an English frog? Well, I think those are the ones, although I never thought of it at the time."

"It seems impossible," said Bob musing and staring at the gigantic tadpole, "but I'll take your word for it."

We set to work with the net once more, and by the time the canoe had returned we had captured two more of these huge tadpoles and were feeling very pleased with ourselves.

Later, when we had returned to our hut, we placed the jar that contained them under a strong light and examined them carefully. Except for their colossal proportions they were exactly like any tadpole you can find in an English pond in the spring. They were, however, a sort of mottled greenish-grey instead of black. The transparent edges of the tail were like frosted glass, and they had ridiculous pursed-up mouths with protruding lips that made them look as though they were blowing kisses at us through the glass.

Watching them wiggling tirelessly round the jar gave one an uncanny feeling. You would feel the same sense of shock if you were walking through the wood one day and you came face to face with an ant the size of a terrier, or a bumblebee as big as a blackbird. They were so very ordinary but, magnified to those fantastic proportions, they took you by surprise and made you wonder if you were dreaming.

Enthusiastic over our paradoxical frogs we returned the following night to the same creek, armed with nets, jars, and other impedimenta. In the first half-hour we caught two more Even's tree frogs and, after much dredging, one more giant tadpole. Then for three hours we caught nothing except bits of twig and a quite remarkable quantity of revolting slush from the creek bed. Eventually I moved further down the bank from the spot where Bob was still hopefully dredging, and I found a narrow, shallow tributary leading into the main creek, little more than a drain and thickly choked with leaves. It meandered away in the distance under a group of stunted trees. Thinking that it might be a more profitable hunting ground, I called Bob over, and we worked our way up the small waterway. But, if anything, it seemed to be more devoid of life than the main creek. Presently I sat down for a smoke, while Bob continued doggedly onwards with his net. I saw him haul his net out, as usual full of sodden leaves, and watched him tip them out on to the bank.

He was just going to plunge his net into the water again when he stopped and peered down at the pile of leaves he had just dredged up.

Then he dropped the net and clutched at the pile of leaves with a delighted squawk.

"What have you got?" I asked.

Bob was dancing about in glee, clasping something in his hands.

"I've got one!" he yelped. "I've got one!"

"What have you got?"

"A pipa toad."

"Nonsense," I said incredulously.

"Come and have a look, then," said Bob, bursting with pride.

He opened his hands for my inspection and disclosed a strange and ugly creature. It looked, to be quite frank, like a brown toad that had been run over by a very heavy steamroller. It's short, rather thin arms and legs stuck out stiffly, one at each corner of its squarish body, and made it look as though rigor mortis had already set in. Its snout was pointed, its eyes minute, and the whole thing was as flat as a pancake. It was, as Bob said, a large male pipa toad, perhaps one of the most curious amphibians in the world. Bob's excitement and pride was understandable, for ever since we had arrived in Guiana we had been trying to get specimens of this creature, without success. And now, in a most unlikely-looking spot, when we were not even thinking about pipa toads, we had captured one. So the misshapen object in Bob's hands sent us into an orgy of delight and self-congratulation, whereas most people would have been rather revolted by their catch and thrown it hurriedly back.

When our excitement had died down a little we set to work and grimly dredged every inch of that small stream, producing a mountain of rotting leaves which we picked over as carefully as a couple of monkeys searching each other's fur. Our perseverance was rewarded, for at the end of an hour we had captured four more of these weird toads.

Moreover one of them was a female with eggs, a prize that was worth anything in our eyes, for the breeding habits of the pipa toad are the most extraordinary thing about it.

During the breeding season, in the case of most species of frog and toad, the sexes can be found together some time before the eggs are actually laid. The male in a frenzy of love clasps the female round the body just below her front legs and remains on her back for quite a long time, clutching her in this nuptial embrace. Eventually the female lays her eggs, and as she does so the male fertilizes them.

In the pipa toad, however, the process is slightly different. The male climbs on to the female's back and clasps her round the chest in the usual manner. But when the eggs are ready to be laid the female protrudes from her anus a long, pipe-like oviposit or which is curved up on to her back and under the male's belly. When this is in place the male starts to wiggle about, moving and pressing the pipe so that the eggs are squeezed out and deposited in uneven rows across the female's skin, where they stick like glue. At the beginning of the breeding season the skin of the female's back becomes soft and spongy, and so when the eggs have been placed and fertilized they sink into the skin, forming cup-like depressions. The glutinous part of the eggs which protrude above the skin surface then hardens and forms little convex covers. So the female pipa has all her eggs in a multitude of little pockets on her back. In these pockets her young spend the whole of their early life, turning from eggs to tadpoles and from tadpoles to toads. When they are fully developed they push up the little lid on top of the pocket and make their way out into the dangerous world.

The female we captured could only just have had her eggs installed, for their lids were still soft. As the weeks passed the skin on her back became more spongy, swollen, and leprous looking and the bulging pockets more pronounced.

When the young were old enough to leave their mother's back they chose a moment when I was on board ship, approximately in the middle of the Atlantic . The toads were housed in kerosene tins and placed, with the rest of the collection, down in the hold of the ship. The first indication I had that there was a happy event imminent among the amphibians was when I went to change their water one morning. The big female was lying, heavy and bloated, spreadeagled on the surface of the water in her usual attitude, looking as all pipa toads look in repose as though she had been dead for some weeks and was already partially decomposed. As I looked at her carefully which I always did to make sure she was not really dead I noticed something moving on her back. Close inspection proved this to be a tiny arm, sticking out of her back and waving about in a feeble manner, and I realized that the great moment had at last arrived. I moved the apparently indifferent mother to a special tin of her own and put this in a convenient position so that I could keep an eye on it during my work, for I was greatly excited and determined not to miss a minute of such a unique birth.

During the morning, whenever I peeped into the tin, there appeared to be much activity going on in the pockets: minute arms and legs stuck out at strange angles, waved vaguely, and were pulled hastily back. Once I found one baby with his head and arms stuck out of his pocket, looking like someone appearing from a manhole. As I tipped the tin to get a better look at him he became shy and struggled frantically back inside his pocket again. The female pipa seemed completely oblivious to the wiggling and kicking and pushing that was going on all over her ample back. She just lay in the water and pretended she was dead.