Of course, one of the favourite tricks in animal warfare is for some harmless creature to persuade a potential enemy that it is really a hideous, ferocious beast, best left alone. One of the most amusing examples of this I have seen was given to me by a sun bittern when I was collecting live animals in British Guiana. This slender bird, with a delicate, pointed beak and slow, stately movements, had been hand-reared by an Indian and was therefore perfectly tame. I used to let it wander freely round my camp during the day and lock it in a cage only at night. Sun bitterns are clad in lovely feathering that has all the hints of an autumn woodland, and sometimes when this bird stood unmoving against a background of dry leaves she seemed to disappear completely. As I say, she was a frail, dainty little bird who, one would have thought, had no defence of any sort against an enemy. But this was not the case.
Three large and belligerent hunting-dogs followed their master into camp one afternoon, and before long one of them spotted the sun bittern, standing lost in meditation on the edge of the clearing. He approached her, his ears pricked, growling softly. The other two quickly joined him, and the three of them bore down on the bird with a swaggering air. The bird let them get within about four feet of her before deigning to notice them. Then she turned her head, gave them a withering stare and turned round to face them. The dogs paused, not quite sure what to do about a bird that did not run squawking at their approach. They moved closer. Suddenly the bittern ducked her head and spread her wings, so that the dogs were presented with a fan of feathers. In the centre of each wing was a beautiful marking, not noticeable when the wings were closed, which looked exactly like the two eyes of an enormous owl glaring at you. The whole transformation was done so slickly, from a slim meek little bird to something that resembled an infuriated eagle owl at bay, that the dogs were taken completely by surprise. They stopped their advance, took one look at the shivering wings and then turned tail and fled. The sun bittern shuffled her wings back into place, preened a few of her breast feathers that had become disarranged and fell to meditating again. It was obvious that dogs did not trouble her in the slightest.
Some of the most ingenious methods of defence in the animal world are displayed by insects. They are masters of the art of disguise, of setting traps, and other methods of defence and attack. But, certainly, one of the most extraordinary is the bombardier beetle.
I was once the proud owner of a genuine wild black rat which I had caught when he was a half-grown youngster. He was an extremely handsome beast with his shining ebony fur and gleaming black eyes. He divided his time equally between cleaning himself and eating. His great passion was for insects of any shape or size: butterflies, praying mantis, stick-insects, cockroaches, they all went the same way as soon as they were put into his cage. Not even the largest praying mantis stood a chance against him, though they would occasionally manage to dig their hooked arms into his nose and draw a bead of blood before he scrunched them up. But one day I found an insect which got the better of him. It was a large, blackish beetle which had been sitting reflecting under a stone that I had inquisitively turned over; and, thinking it would make a nice titbit for my rat, I put it in a matchbox in my pocket. When I arrived home I pulled the rat out of his sleeping-box, opened the matchbox and shook the large succulent beetle on to the floor of his cage. Now the rat had two methods of dealing with insects, which varied according to their kind. If they were as fast-moving and as belligerent as a mantis, he would rush in and bite as quickly as possible in order to destroy it, but with anything harmless and slow, like a beetle, he would pick it up in his paws and sit scrunching it up as though it were a piece of toast.
Seeing this great fat delicacy wandering rather aimlessly around on the floor of his cage, he trotted forward, rapidly seized it with his little pink paws and then sat back on his haunches with the air of a gourmet about to sample the first truffle of the season. His whiskers twitched in anticipation as he lifted the beetle to his mouth, and then a curious thing happened. He uttered the most prodigious sniff, dropped the beetle and leaped backwards as though he had been stung, and sat rubbing his paws hastily over his nose and face. At first I thought he had merely been taken with a sneezing fit just as he was about to eat the beetle. Having wiped his face, he again approached it, slightly more cautiously this time, picked it up and lifted it to his mouth. Then he uttered a strangled snort, dropped it as though it were red-hot and sat wiping his face indignantly. The second experience had obviously been enough for him, for he refused to go near the beetle after that; in fact he seemed positively scared of it. Every time it ambled round to the corner of the cage where he was sitting, he would back away hurriedly. I put the beetle back in the matchbox and took it inside to identify it and it was only then that I discovered that I had offered my unfortunate rat a bombardier beetle. Apparently the beetle, when attacked, squirts out a liquid which, on reaching the air, explodes with a tiny crack and forms a sort of pungent and unpleasant gas, sufficiently horrible to make any creature who has experienced it leave the bombardier beetle severely alone in future.
I felt rather sorry for my black rat. It was, I felt, an unfortunate experience to pick up what amounted to a particularly delicious dinner, only to have it suddenly turn into a gas attack in your paws. It gave him a complex about beetles, too, because for days afterwards he would dash into his sleeping-box at the sight of one, even a fat and harmless dung-beetle. However, he was a young rat, and I suppose he had to learn at some time or another that one cannot judge by appearances in this life.
Animal Inventors
I once travelled back from Africa on a ship with an Irish captain who did not like animals. This was unfortunate, because most of my luggage consisted of about two hundred-odd cages of assorted wild life, which were stacked on the forward well deck. The captain (more out of devilment than anything else, I think) never missed a chance of trying to provoke me into an argument by disparaging animals in general and my animals in particular. But fortunately I managed to avoid getting myself involved. To begin with, one should never argue with the captain of a ship, and to argue with a captain who was also an Irishman was simply asking for trouble. However, when the voyage was drawing to an end, I felt the captain needed a lesson and I was determined to teach him one if I could.
One evening when we were nearing the English Channel, the wind and rain had driven us all into the smoking-room, where we sat and listened to someone on the radio giving a talk on radar, which in those days was still sufficiently new to be of interest to the general public. The captain listened to the talk with a gleam in his eye, and when it had finished he turned to me.
‘So much for your animals,’ he said, ‘they couldn’t produce anything like that, in spite of the fact that, according to you, they’re supposed to be so clever.’
By this simple statement the captain had played right into my hands, and I prepared to make him suffer.
‘What will you bet,’ I inquired, ‘that I can’t describe at least two great scientific inventions and prove to you that the principle was being used in the animal world long before man ever thought of it?’
‘Make it four inventions instead of two and I’ll bet you a bottle of whisky,’ said the captain, obviously feeling he was on to a good thing. I agreed to this.
‘Well,’ said the captain smugly, ‘off you go.’
‘You’ll have to give me a minute to think,’ I protested.
‘Ha,’ said the captain triumphantly, ‘you’re stuck already.’
‘Oh, no,’ I explained, ‘it’s just that there are so many examples I’m not sure which to choose.’
The captain gave me a dirty look.
‘Why not try radar, then?’ he inquired sarcastically.
‘Well, I could,’ I said, ‘but I really felt it was too easy. However, since you choose it, I suppose I’d better.’
It was fortunate for me that the captain was no naturalist; otherwise he would never have suggested radar. It was a gift, from my point of view, because I
simply described the humble bat.
Many people must have been visited by a bat in their drawing-room or bedroom at one time or another, and if they have not been too scared of it, they will have been fascinated by its swift, skilful flight and the rapid twists and turns with which it avoids all obstacles, including objects like shoes and towels that are sometimes hurled at it. Now, despite the old saying, bats are not blind. They have perfectly good eyes, but these are so tiny that they are not easily detected in the thick fur. Their eyes, however, are certainly not good enough for them to perform some of the extraordinary flying stunts in which they indulge. It was an Italian naturalist called Spallanzani, in the eighteenth century, who first started to investigate the flight of bats, and by the unnecessarily cruel method of blinding several bats he found that they could still fly about unhampered, avoiding obstacles as though they were uninjured. But how they managed to do this he could not guess.
It was not until fairly recently that this problem was solved, at least partially. The discovery of radar, the sending out of sound-waves and judging the obstacles ahead by the returning echo, made some investigators wonder if this was not the system employed by bats. A series of experiments was conducted, and some fascinating things were discovered. First of all, some bats were blindfolded with tiny pieces of wax over their eyes, and as usual they had no difficulty in flying to and fro without hitting anything. Then it was found that if they were blindfolded and their ears were covered they were no longer able to avoid collisions, and, in fact, did not seem at all keen on flying in the first place. If only one ear was covered they could fly with only moderate success, and would frequently hit objects. This showed that bats could get information about the obstacles ahead by means of sound-waves reflected from them. Then the investigators covered the noses and mouths of their bats, but left the ears uncovered, and again the bats were unable to fly without collision. This proved that the nose, ears and mouth all played some part in the bat’s radar system. Eventually, by the use of extremely delicate instruments, the facts were discovered. As the bat flies along, it emits a continuous succession of supersonic squeaks, far too high for the human ear to pick up. They give out, in fact, about thirty squeaks a second. The echoes from these squeaks, bouncing off the obstacles ahead, return to the bat’s ears and, in some species, to the curious fleshy ridges round the creature’s nose, and the bat can thus tell what lies ahead, and how far away it is. It is, in fact, in every detail the principle of radar. But one thing rather puzzled the investigators: when you are transmitting sound-waves on radar, you must shut off your receiver when you are actually sending out the sound, so that you receive only the echo. Otherwise the receiver would pick up both the sound transmitted and the echo back, and the result would be a confused jumble. This might be possible on electrical apparatus, but they could not imagine how the bats managed to do it. It was then discovered that there was a tiny muscle in the bat’s ear that did the job. Just at the moment the bat squeaks, this muscle contracts and puts the ear out of action. The squeak over, the muscle relaxes and the ear is ready to receive the echo.
But the amazing thing about this is not that bats have this private radar system – for after a while very little surprises one in Nature – but that they should have had it so long before man did. Fossil bats have been found in early Eocene rocks, and they differed very little from their modern relatives. It is possible, therefore, that bats have been employing radar for something like fifty million years. Man has possessed the secret for about twenty.
It was quite obvious that my first example had made the captain think. He did not seem quite so sure of winning the bet. I said that my next choice would be electricity, and this apparently cheered him up a bit. He laughed in a disbelieving way, and said I would have a job to persuade him that animals had electric lights. I pointed out that I had said nothing about electric lights, but merely electricity, and there were several creatures that employed it. There is, for example, the electric-ray or torpedo-fish, a curious creature that looks rather like a frying-pan run over by a steam-roller. These fish are excessively well camouflaged: not only does their colouring imitate the sandy bottom but they have also the annoying habit of half-burying themselves in the sand, which renders them really invisible. I remember once seeing the effect of this fish’s electric organs, which are large and situated on its back. I was in Greece at the time, and was watching a young peasant boy fishing in the shallow waters of a sandy bay. He was wading up to his knees in the clear waters, holding in his hand a three-pronged spear such as the fishermen used for night-fishing. As he made his way round the bay, he was having quite a successful time: he had speared several large fish and a young octopus which had been concealed in a small group of rocks. As he came opposite where I was sitting a curious and rather startling thing happened. One minute he was walking slowly forward, peering down intently into the water, his trident at the ready; the next minute he had straightened up as stiffly as a guardsman and projected himself out of the water like a rocket, uttering a yell that could have been heard half a mile away. He fell back into the water with a splash and immediately uttered another and louder scream and leapt up again. This time he fell back into the water and seemed unable to regain his feet, for he struggled out on to the sand, half crawling, half dragging himself. When I got down to where he lay, I found him white and shaking, panting as though he had just run half a mile. How much of this was due to shock and how much to the actual effect of the electricity I could not tell, but at any rate I never again went bathing in that particular bay.
Probably the most famous electricity-producing creature is the electric-eel which, strangely enough, is not an eel at all but a species of fish that looks like an eel. These long, black creatures live in the streams and rivers of South America and can grow to eight feet in length and the thickness of a man’s thigh. No doubt a lot of stories about them are grossly exaggerated, but it is possible for a big one to shock a horse fording a river strongly enough to knock down the animal.
When I was collecting animals in British Guiana I very much wanted to catch some electric-eels to bring back to this country. At one place where we were camped the river was full of them, but they lived in deep caves hollowed out in the rocky shores. Most of these caves communicated with the air by means of round pot-holes that had been worn by the flood waters, and in the cave beneath each pot-hole lived an electric-eel. If you made your way to a pot-hole and stamped heavily with your shoes it would annoy the eel into replying with a strange purring grunt, as though a large pig were entombed beneath your feet.
Try as I would I did not manage to catch one of these eels. Then one day my partner and I, accompanied by two Indians, went for a trip to a village a few miles away, where the inhabitants were great fishermen. We found several animals and birds in the village which we purchased from them, including a tame tree-porcupine. Then, to my delight, someone appeared with an electric-eel in a rather insecure fish-basket. Having bargained for and bought these creatures, including the eel, we piled them into the canoe and set out for home. The porcupine sat in the bow, apparently very interested in the scenery, and in front of him lay the eel in its basket. We were half-way home when the eel escaped.
We were first made aware of this by the porcupine. He was, I think, under the impression that the eel was a snake, for he galloped down from the bows and endeavoured to climb on to my head. Struggling to evade the porcupine’s prickly embrace, I suddenly saw the eel wriggling determinedly towards me, and indulged in a feat which I would not have believed possible. I leapt into the air from a sitting position, clasping the porcupine to my bosom, and landed again when the eel had passed, without upsetting the canoe. I had a very vivid mental picture of what had happened to the young peasant who had trodden on the torpedo-fish, and I had no intention of indulging in a similar experience with an electric-eel. Luckily none of us received a shock from the eel, for while we were trying to juggle it back into its basket it wriggled over the side of the canoe
and fell into the river. I cannot say any of us were really sorry to see it go.
I remember once feeding an electric-eel that lived in a large tank in a zoo, and it was quite fascinating to watch his method of dealing with his prey. He was about five feet long and could cope adequately with a fish of about eight or ten inches in length. These had to be fed to him alive, and as their death was instantaneous, I had no qualms about this. The eel seemed to know when it was feeding-time and he would be patrolling his tank with the monotonous regularity of a sentry outside Buckingham Palace. As soon as a fish was dropped into his tank he would freeze instantly and apparently watch it as it swam closer and closer. When it was within range, which was about a foot or so, he would suddenly appear to quiver all over as if a dynamo had started within his long dark length. The fish would be, as it were, frozen in its tracks; it was dead before you realized that anything was happening, and then very slowly it would tilt over and start floating belly uppermost. The eel would move a little closer, open his mouth and suck violently, and, as though he were an elongated vacuum-cleaner, the fish would disappear into him.
Having dispensed quite successfully, I thought, with electricity, I now turned my attention to another field: medicine. Anaesthetics, I said, would be my next example, and the captain looked if anything even more sceptical than before.