Notes on Reptiles, extracted from The Naturalist in La Plata
W. H. Hudson

The hairy armadillo will, doubtless, long survive all the other armadillos, and on this account alone it will have an ever-increasing interest for the naturalist.  I have elsewhere described how it captures mice; when preying on snakes it proceeds in another manner.  A friend of mine, a careful observer, who was engaged in cattle-breeding amongst the stony sierras near Cape Corrientes, described to me an encounter he witnessed between an armadillo and a poisonous snake.  While seated on the hillside one day he observed a snake, about twenty inches in length, lying coiled up on a stone five or six yards beneath him.  By-and-by, a hairy armadillo appeared trotting directly towards it.  Apparently the snake perceived and feared its approach, for it quickly uncoiled itself and began gliding away.  Instantly the armadillo rushed on to it, and, squatting close down, began swaying its body backward and forward with a regular sawing motion, thus lacerating its victim with the sharp, deep-cut edges of its bony covering.  The snake struggled to free itself, biting savagely at its aggressor, for its head and neck were disengaged.  Its bites made no impression, and very soon it dropped its head, and when its enemy drew off, it was dead and very much mangled.  The armadillo at once began its meal, taking the tail in its mouth and slowly progressing towards the head; but when about a third of the snake still remained it seemed satisfied, and, leaving that portion, trotted away.

Altogether, in its rapacious and varied habits this armadillo appears to have some points of resemblance with the hedgehog; and possibly, like the little European mammal it resembles, it is not harmed by the bite of venomous snakes.

I once had a cat that killed every snake it found, purely for sport, since it never ate them.  It would jump nimbly round and across its victim, occasionally dealing it a blow with its cruel claws.  The enemies of the snake are legion.  Burrowing owls feed largely on them; so do herons and storks, killing them with a blow of their javelin beaks, and swallowing them entire.  The sulphur tyrant-bird picks up the young snake by the tail, and, flying to a branch or stone, uses it like a flail till its life is battered out.  The bird is highly commended in consequence, reminding one of very ancient words: "Happy shall he be that taketh thy little ones and dasheth them against the stones."  In arraying such a variety of enemies against the snake, nature has made ample amends for having endowed it with deadly weapons.  Besides, the power possessed by venomous snakes only seems to us disproportionate; it is not really so, except in occasional individual encounters.  Venomous snakes are always greatly outnumbered by non-venomous ones in the same district; at any rate this is the case on the pampas.  The greater activity of the latter counts for more in the result than the deadly weapons of the former.

The large teguexin lizard of the pampas, called iguana by the country people, is a notable snake-killer.  Snakes have, in fact, no more formidable enemy, for he is quick to see, and swift to overtake them.  He is practically invulnerable, and deals them sudden death with his powerful tail.  The gauchos say that dogs attacking the iguana are sometimes known to have their legs broken, and I do not doubt it.  A friend of mine was out riding one day after his cattle, and having attached one end of his lasso to the saddle, he let it trail on the ground.  He noticed a large iguana lying apparently asleep in the sun, and though he rode by it very closely, it did not stir; but no sooner had he passed it, than it raised its head, and fixed its attention on the forty feet of lasso slowly trailing by.  Suddenly it rushed after the rope, and dealt it a succession of violent blows with its tail.  When the whole of the lasso, several yards of which had been pounded in vain, had been dragged by, the lizard, with uplifted head, continued gazing after it with the greatest astonishment.  Never had such a wonderful snake crossed its path before!

.....

On another occasion, in the middle of the hot season, I was travelling alone across-country in a locality which was new to me, a few leagues east of La Plata River, in its widest part.  About eleven o'clock in the morning I came to a low-lying level plain where the close-cropped grass was vivid green, although elsewhere all over the country the vegetation was scorched and dead, and dry as ashes.  The ground being so favourable, I crossed this low plain at a swinging gallop, and in about thirty minutes' time.  In that half-hour I saw a vast number of snakes, all of one kind, and a species new to me; but my anxiety to reach my destination before the oppressive heat of the afternoon made me hurry on.  So numerous were the snakes in that green place that frequently I had as many as a dozen in sight at one time.  It looked to me like a Coronella—harmless colubrine snakes—but was more than twice as large as either of the two species of that genus I was already familiar with.  In size they varied greatly, ranging from two to fully five feet in length, and the colour was dull yellow or tan, slightly lined and mottled with shades of brown.  Among dead or partially withered grass and herbage they would have been undistinguishable at even a very short distance, but on the vivid green turf they were strangely conspicuous, some being plainly visible forty or fifty yards away; and not one was seen coiled up.  They were all lying motionless, stretched out full length, and looking like dark yellow or tan-coloured ribbons, thrown on to the grass.  It was most unusual to see so many snakes together, although not surprising in the circumstances.  The December heats had dried up all the watercourses and killed the vegetation, and made the earth hard and harsh as burnt bricks; and at such times snakes, especially the more active non-venomous kinds, will travel long distances, in their slow way, in search of water.  Those I saw during my ride had probably been attracted by the moisture from a large area of country; and although there was no water, the soft fresh grass must have been grateful to them.  Snakes are seen coiled up when they are at home; when travelling and far afield, they lie, as a rule, extended full length, even when resting—and they are generally resting.  Pausing at length, before quitting this green plain, to give my horse a minute's rest, I got off and approached a large snake; but when I was quite twelve yards from it, it lifted its head, and, turning deliberately round, came rather swiftly at me.  I retreated, and it followed, until, springing on to my horse, I left it, greatly surprised at its action, and beginning to think that it must be venomous.  As I rode on, the feeling of surprise increased, conquering haste; and in the end, seeing more snakes, I dismounted and approached the largest, when exactly the same thing occurred again, the snake rousing itself and coming angrily at me when I was still (considering the dull lethargic character of the deadliest kinds) at an absurd distance from it.  Again and again I repeated the experiment, with the same result.  And at length I stunned one with a blow of my whip to examine its mouth, but found no poison-fangs in it.

I then resumed my journey, expecting to meet with more snakes of the same kind at my destination; but there were none, and very soon business called me to a distant place, and I never met with this species afterwards.  But when I rode away from that green spot, and was once more on the higher, desolate, wind-swept plain surrounding it—a rustling sea of giant thistles, still erect, although dead, and red as rust, and filling the hot, blue sky with silvery down—it was with a very strange feeling.  The change from the green and living to the dead, and dry, and dusty, was so great! There seemed to be something mysterious, extra-natural, in that low, level plain, so green, and fresh, and snaky, where my horse's hoofs had made no sound—a place where no man dwelt, and no cattle pastured, and no wild bird folded its wing.  And the serpents there were not like others—the mechanical coiled-up thing we know, a mere bone-and-muscle man-trap, set by the elements, to spring and strike when trodden on: but these had a high intelligence, a lofty spirit, and were filled with a noble rage and astonishment that any other kind of creature, even a man, should venture there to disturb their sacred peace.  It was a fancy, born of that sense of mystery which the unknown and the unusual in nature wakes in us—an obsolescent feeling that still links us to the savage.  But the simple fact was wonderful enough, and that has been set down simply, and apart from all fancies.  If the reader happens not to be a naturalist, it is right to tell him that a naturalist cannot exaggerate consciously; and if he be capable of unconscious exaggeration, then he is no naturalist. He should hasten "to join the innumerable caravan that moves" to the fantastic realms of romance.  Looking at the simple fact scientifically, it was a case of mimicry—the harmless snake mimicking the fierce, threatening gestures and actions proper to some deadly kind.  Only with this difference: the venomous snake, of all deadly things in nature, is the slowest to resentment, the most reluctant to enter into a quarrel; whereas, in this species, angry demonstrations were made when the intruder was yet far off, and before he had shown any hostile intentions.