Narrative of the surveying voyages of His Majesty's Ships Adventure and Beagle, Vol. 3 [of 3] · Charles Darwin
BAHIA BLANCA.
When at the Rio Negro, in Northern Patagonia, I repeatedly heard the Gauchos talking of a very rare bird which they called Avestruz Petise. They described it as being less than the common ostrich (which is there abundant), but with a very close general resemblance. They said its colour was dark and mottled, and that its legs were shorter, and feathered lower down than those of the common ostrich. It is more easily caught by the bolas than the other species. The few inhabitants who had seen both kinds, affirmed they could distinguish them apart from a long distance. The eggs of the small species appeared, however, more generally known; and it was remarked, with surprise, that they were very little less than those of the Rhea, but of a slightly different form, and with a tinge of pale blue. Some eggs, picked up on the plains of Patagonia, agree pretty well with this description, and I do not doubt are those of the Petise. This species occurs most rarely on the plains bordering the Rio Negro; but about a degree and a half further south they are tolerably abundant. One Gaucho, however, said he distinctly recollected having seen one, many years before, near the mouth of the Rio Colorado, which is to the north of the Rio Negro.
They are said to prefer the plains near the sea. When at Port Desire, in Patagonia (lat. 48°), Mr. Martens shot an ostrich; and I looked at it, forgetting at the moment, in the most unaccountable manner, the whole subject of the Petises, and thought it was a two-third grown one of the common sort. The bird was cooked and eaten before my memory returned. Fortunately the head, neck, legs, wings, many of the larger feathers, and a large part of the skin, had been preserved. From these a very nearly perfect specimen has been put together, and is now exhibited in the museum of the Zoological Society. Mr. Gould, who in describing this new species did me the honour of calling it after my name, states, that besides the smaller size and different colour of the plumage, the beak is of considerably less proportional dimensions than in the common Rhea; that the tarsi are covered with differently-shaped scales, and that they are feathered six inches beneath the knee. In this latter respect, and in the broader feathers of the wing, this bird perhaps shows more affinity to the gallinaceous family than any other of the Struthionidæ.
Among the Patagonian Indians in the Strait of Magellan, we found a half Indian, who had lived some years with the tribe, but had been born in the northern provinces. I asked him if he had ever heard of the Avestruz Petise? He answered by saying, “Why there are none others in these southern countries.” He informed me that the number of eggs in the nest of the petise is considerably less than with the other kind, namely, not more than fifteen on an average; but he asserted that more than one female deposited them. At Santa Cruz we saw several of these birds. They were excessively wary: I think they could see a person approaching when he was so far off as not to distinguish the ostrich. In ascending the river few were seen; but in our quiet and rapid descent, many, in pairs and by fours or fives, were observed. It was remarked, and I think with truth, that this bird did not expand its wings, when first starting at full speed, after the manner of the northern kind. The fact of these ostriches swimming across the river has been mentioned. In conclusion, I may repeat that the _Struthio Rhea_ inhabits the country of La Plata as far as a little south of the Rio Negro, in lat.
41°, and that the petise takes its place in Southern Patagonia; the part about the Rio Negro being neutral territory. Wallis saw ostriches at Batchelor’s river (lat. 53° 54′), in the Strait of Magellan, which must be the extreme southern possible range of the petise. M. D’Orbigny, when at the Rio Negro, made great exertions to procure this bird, but never had the good fortune to succeed. He mentions it in his Travels,[14] and proposes (in case, I presume, of a specimen being obtained) to call it _Rhea pennata_: a fuller notice was given long before in Dobrizhoffer’s Account of the Abipones[15] (A.D. 1749). He says, “You must know, moreover, that Emus differ in size and habits in different tracts of land; for those that inhabit the plains of Buenos Ayres and Tucuman are larger, and have black, white, and gray feathers; those near to the Strait of Magellan are smaller and more beautiful, for their white feathers are tipped with black at the extremity, and their black ones in like manner terminate in white.”
A very singular little bird, lately described by St. Hilaire and Lesson under the name of _Tinochorus Eschscholtzii_, is here common. In its habits, general appearance, and structure, it nearly equally partakes of the character of a quail and a snipe. Yet these two birds are widely contrasted in the form of their beaks, wings, and legs. The Tinochorus is found in the whole of southern South America, wherever there are sterile plains, or open dry pasture-land. We saw it as far south as the inland plains of Patagonia at Santa Cruz, in lat. 50°. On the western side of the Cordillera near Concepcion, where the forest land changes into an open country, this bird is found: from that point throughout Chile, as far as Copiapó, it frequents the most desolate places, where scarcely another living creature can exist. They are found either in pairs or small flocks of five or six; but near the Sierra Ventana I saw as many as thirty or forty together. Upon being approached they squat close, and then are very difficult to be distinguished; so that they often rise quite unexpectedly. When feeding they walk rather slowly, with their legs wide apart. They dust themselves in roads and sandy places. They frequent particular spots, and may be found there day after day.
When a pair are together, if one is shot the other seldom rises; for these birds, like partridges, only take wing in a flock. In all these respects, in the muscular gizzard adapted for vegetable food, in the arched beak and fleshy nostrils, short legs and form of foot, the Tinochorus has a close affinity with quails. But directly the bird is seen flying, one’s opinion is changed; the long, pointed wings, so different from those in the gallinaceous order, the irregular manner of flight, and plaintive cry uttered at the moment of rising, recall the idea of a snipe. The sportsmen of the Beagle unanimously called it the shortbilled snipe. To this genus, or rather to that of the sandpiper, it approaches, as Mr. Gould informs me, in the shape of its wing, the length of the scapulars, the form of the tail, which closely resembles that of _Tringa hypoleucos_, and in the general colour of the plumage. The male bird, however, has a black mark on its breast, in the form of a yoke, which may be compared to the horseshoe on the breast of the English partridge. The nest is said to be placed on the borders of lakes, although the bird itself is an inhabitant of the parched desert.
The Tinochorus is closely related to some other South American birds. Two species of the genus Attagis, are in almost every respect ptarmigans in their habits; one in Tierra del Fuego, above the limits of forest land; the other just beneath the snow-line on the Cordillera of Central Chile. A bird of another closely-allied genus, _Chionis alba_, which solitary species was long thought to form a family by itself, is an inhabitant of the antarctic regions; it feeds on sea-weed and shells on the tidal rocks. Although not web-footed, from some unaccountable taste it is frequently met with far out at sea. This small family of birds is one of those which, from its varied relations, although at present offering only difficulties to the systematic naturalist, ultimately may assist in revealing the grand scheme, common to the present and past ages, on which organized beings have been created. I may also briefly notice the genus Furnarius. It contains several species, all small birds, living on the ground, and inhabiting open, dry countries. In structure they cannot be compared to any European form. Ornithologists have generally included them among the creepers, although opposed to that family in every habit. The best known species is the common oven-bird of La Plata, the Casara or house-maker of the Spaniards, and _Furnarius rufus_ of Viell. The nest, whence it takes its name, is placed in the most exposed situations, as on the top of a post, a bare rock, or on a cactus. It is composed of mud and bits of straw, and has strong thick walls: in shape it precisely resembles an oven, or depressed beehive. The opening is large and arched, and directly in front, within the nest, there is a partition, which reaches nearly to the roof, thus forming a passage or antechamber to the true nest.
Another and smaller species of Furnarius, something like a lark in appearance, resembles the oven-bird in many points, as in the general reddish tint of its plumage, a peculiar shrill reiterated cry, an odd manner of running by starts, &c. From its affinity, the Spaniards call it Casarita (or little housebuilder), although its nidification is quite different. The Casarita builds its nest at the bottom of a narrow cylindrical hole, which is said to extend horizontally to nearly six feet under ground. Several of the country people told me, that when boys they had attempted to dig out the nest, but had scarcely ever succeeded in getting to the end. The bird chooses any low bank of firm sandy soil by the side of a road or stream. Here (at Bahia Blanca) the walls are built of hardened mud; and I noticed that one, which enclosed a courtyard where I lodged, was penetrated by round holes in a score of places. On asking the owner the cause of this, he bitterly complained of the little casarita, several of which I afterwards observed at work. It is rather curious, that although they were constantly flitting over the low wall, they must be quite incapable of gaining an idea of thickness even after the shortest circuitous route, for otherwise they would not have made so many vain attempts. I do not doubt that each bird, as often as it came to daylight on the opposite side, was greatly surprised at the marvellous fact.
I have already mentioned nearly all the mammalia common in this country. Of armadilloes three species occur, namely, the Dasypus minutus or _pichy_, the Villosus or _peludo_, and the _apar_. The first extends as far south as lat. 50°, which is about ten degrees further than any other kind. A fourth species, the _Mulita_, only extends as far south as the Sierra Tapalguen, lat. 37° 30′, which is north of Bahia Blanca. The four species have nearly similar habits; the _peludo_, however, is nocturnal, while the others wander by day over the open plains, feeding on beetles, larvæ, roots, and even small snakes. The _apar_, commonly called _mataco_, is remarkable by having only three moveable bands; the rest of its tesselated covering being nearly inflexible. It has the power of rolling itself into a perfect sphere, like one kind of English woodlouse. In this state it is safe from the attack of dogs; for the dog not being able to take the whole in its mouth, tries to bite one side, and the ball slips away. The smooth hard covering of the _mataco_ offers a better defence than the sharp spines of the hedgehog. The _pichy_ prefers a very dry soil, and the sand-dunes near the coast, where for many months it can never taste water, is its favourite resort. In the course of a day’s ride, near Bahia Blanca, several were generally met with. The instant one was perceived, it was necessary in order to catch it, almost to tumble off one’s horse; for if the soil was soft, the animal burrowed so quickly, that its hinder quarters had almost disappeared before one could alight. The _pichy_ likewise often tries to escape notice, by squatting close to the ground. It appears almost a pity to kill such nice little animals, for as a Gaucho said, while sharpening his knife on the back of one, “Son tan mansos” (they are so quiet).
Of reptiles there are many kinds: one snake (a Trigonocephalus, or more properly a Cophias), from the size of the poison channel in its fangs, must be very deadly. Cuvier, in opposition to some other naturalists, makes this a sub-genus of the rattlesnake, and intermediate between it and the viper. In confirmation of this opinion, I observed a fact, which appears to me very curious and instructive, as showing how every character, even though it may be in some degree independent of structure, has a tendency to vary by slow degrees. The extremity of the tail of this snake is terminated by a point, which is very slightly enlarged; and as the animal glided along, it constantly vibrated the last inch; and this part striking against the dry grass and brushwood, produced a rattling noise, which could be distinctly heard at the distance of six feet. As often as the animal was irritated or surprised, its tail was shaken; and the vibrations were extremely rapid. Even as long as the body retained its irritability, a tendency to this habitual movement was evident. This Trigonocephalus has, therefore, in some respects the structure of Vipera, with the habits of a Crotalus; the noise, however, being produced by a simpler device. The expression of this snake’s face was hideous and fierce; the pupil consisted of a vertical slit in a mottled and coppery iris; the jaws were broad at the base, and the nose terminated in a triangular projection. I do not think I ever saw any thing more ugly, excepting, perhaps, in some of the vampire bats. I imagine this repulsive aspect originates from the features being placed in positions, with respect to each other, somewhat proportional to those of the human face; and thus we obtain a scale of beauty.
Amongst the Batrachian reptiles, I found only one little toad, which was most singular from its colour. If we imagine, first, that it had been steeped in the blackest ink, and then when dry, allowed to crawl over a board, freshly painted with the brightest vermilion, so as to colour the soles of its feet and parts of its stomach, a good idea of its appearance will be gained. If it is an unnamed species, surely it ought to be called _diabolicus_, for it is a fit toad to preach in the ear of Eve. Instead of being nocturnal in its habits, as other toads are, and living in damp obscure recesses, it crawls during the heat of the day about the dry sand-hillocks and arid plains, where not a single drop of water can be found. It must necessarily depend on the dew for its moisture; and this probably is absorbed by the skin, for it is known, that these reptiles possess great powers of cutaneous absorption. At Maldonado, I found one in a situation nearly as dry as at Bahia Blanca, and thinking to give it a great treat, carried it to a pool of water; not only was the little animal unable to swim, but, I think, without help would soon have been drowned. Of lizards there were many kinds, but only one remarkable, from its habits. It lives on the bare sand near the sea-coast, and from its mottled colour, the brownish scales being speckled with white, yellowish red, and dirty blue, can hardly be distinguished from the surrounding surface. When frightened it attempts to avoid discovery by feigning death, with outstretched legs, depressed body, and closed eyes: if further molested, it buries itself with great quickness in the loose sand. This lizard, from its flattened body and short legs, cannot run quickly. It belongs to the genus Ophryessa.
I will here add a few remarks on the hybernation of animals in this part of South America. When we first arrived at Bahia Blanca, September 7th, 1832, we thought nature had granted scarcely a living creature to this sandy and dry country. By digging, however, in the ground, several insects, large spiders, and lizards were found in a half torpid state. On the 15th, a few animals began to appear, and by the 18th (three days from the equinox), every thing announced the commencement of spring. The plains were ornamented by the flowers of a pink wood sorrel, wild peas, œnotheræ, and geraniums; and the birds began to lay their eggs. Numerous Lamellicorn and Heteromerous insects, the latter remarkable for their deeply sculptured bodies, were slowly crawling about; while the Saurian tribe, the constant inhabitants of a sandy soil, darted in every direction. During the first eleven days, whilst nature was dormant, the mean temperature taken from observations made every two hours on board the Beagle, was 51°; and in the middle of the day the thermometer seldom ranged above 55°. On the eleven succeeding days, in which all living things became so animated, the mean was 58°, and the range in the middle of the day between sixty and seventy.
Here then an increase of seven degrees in mean temperature, but a greater one of extreme heat, was sufficient to awake the functions of life. At Monte Video, from which we had just before sailed, in the twenty-three days included between the 26th of July and the 19th of August, the mean temperature from 276 observations was 58°.4; the mean hottest day being 65°.5, and the coldest 46°. The lowest point to which the thermometer fell was 41°.5, and occasionally in the middle of the day it rose to 69° or 70°. Yet with this elevated temperature, almost every beetle, several genera of spiders, snails, and land-shells, toads, and lizards were all lying torpid beneath stones. But we have seen that at Bahia Blanca, which is four degrees to the southward, and therefore with a climate only a very little colder, this same temperature with a rather less extreme heat, was sufficient to awake all orders of animated beings. This shows how nicely the required degree of stimulus is adapted to the general climate of the place, and how little it depends on absolute temperature. It is well known that within the tropics, the hybernation, or more properly estivation, of animals is governed by the times of drought. Near Rio de Janeiro, I was at first surprised to observe, that, a few days after some little depressions had been changed into pools of water by the rain, they were peopled by numerous full-grown shells and beetles. Humboldt has related the strange accident of a hovel having been erected over a spot, where a young crocodile lay buried in the hardened mud. He adds “The Indians often find enormous boas; which they call Uji, or water serpents, in the same lethargic state. To reanimate them, they must be irritated or wetted with water.”
I will only mention one other animal, a zoophyte allied to Virgularia,[16] a kind of sea-pen. It consists of a thin, straight, fleshy stem, with alternate rows of polypi on each side, and surrounding an elastic stony axis. It varies in length from eight inches to two feet. The stem at one extremity is truncate, but at the other is terminated by a vermiform fleshy appendage, which is separated into two compartments; and in these, small, yellow, spherical ova are contained. The stony axis which gives strength to the stem, may be traced at this extremity into a mere vessel filled with granular matter. This undeveloped portion is enclosed in a transparent, elastic, irritable bag, containing a fluid in which a very distinct circulation of particles could be seen. This bag floats in one of the compartments of the fleshy terminal appendage. At low water hundreds of these zoophytes might be seen, projecting like stubble, with the truncate end upwards, a few inches above the surface of the muddy sand. When touched or pulled, they drew themselves in, suddenly and with force, so as nearly or quite to disappear.
By this action, the highly elastic axis must be bent at the lower extremity, where it is naturally slightly curved; and I imagine it is by this elasticity that the zoophyte is enabled to rise again through the mud. Each polypus, though closely united to its brethren, has a distinct mouth, body, and tentacula. Of these polypi, in a large specimen, there must be many thousands; yet we see that they act by one movement; that they have one central axis connected with a system of obscure circulation; and that the ova are produced in an organ distinct from the separate individuals. Well may one be allowed to ask, what is an individual? I will add only one other observation on this zoophyte. The cavities leading from the fleshy compartments of the extremity, were filled with a yellow pulpy matter, which, examined under a microscope, presented an extraordinary appearance. The mass consisted of rounded, semi-transparent, irregular grains, aggregated together into particles of various sizes. All such particles, and the separate grains, possessed the power of rapid movement; generally revolving around different axes, but sometimes progressive. The movement was visible with a very weak power, but with the highest its cause could not be perceived. It was very different from the circulation of the fluid in the elastic bag, containing the thin extremity of the axis. On other occasions, when dissecting small marine animals beneath the microscope, I have seen particles of pulpy matter, some of large size, immediately they were disengaged, commence revolving. I have imagined, I know not with how much truth, that this granulo-pulpy matter was in process of being converted into ova. Certainly in this zoophyte such appeared to be the case.
In the morning they started for the scene of the murder, with orders to follow the “rastro,” or track, even if it led them to Chile. We subsequently heard that the wild Indians had escaped into the great Pampas, and from some cause the track had been missed. One glance at the rastro tells these people a whole history. Supposing they examine the track of a thousand horses, they will soon guess by seeing how many have cantered the number of men; by the depth of the other impressions, whether any horses were loaded with cargoes; by the irregularity of the footsteps, how far tired; by the manner in which the food has been cooked, whether the pursued travelled in haste; by the general appearance, how long it has been since they passed. They consider a rastro of ten days or a fortnight, quite recent enough to be hunted out. We also heard that Miranda struck from the west end of the Sierra Ventana, in a direct line to the island of Cholechel, situated seventy leagues up the Rio Negro. This is a distance of between two and three hundred miles, through a country completely unknown. What other troops in the world are so independent? With the sun for their guide, mares’ flesh for food, their saddle-cloths for beds,--as long as there is a little water, these men would penetrate to the land’s end.
A few days afterwards I saw another troop of these banditti-like soldiers start on an expedition against a tribe of Indians at the small salinas, who had been betrayed by a prisoner cacique. The Spaniard who brought the orders for this expedition was a very intelligent man. He gave me an account of the last engagement at which he was present. Some Indians, who had been taken prisoners, gave information of a tribe living north of the Colorado. Two hundred soldiers were sent; and they first discovered the Indians by a cloud of dust from their horses’ feet, as they chanced to be travelling. The country was mountainous and wild, and it must have been far in the interior, for the Cordillera was in sight. The Indians, men, women, and children, were about one hundred and ten in number, and they were nearly all taken or killed, for the soldiers sabre every man. The Indians are now so terrified, that they offer no resistance in a body, but each flies, neglecting even his wife and children; but when overtaken, like wild animals, they fight against any number to the last moment. One dying Indian seized with his teeth the thumb of his adversary, and allowed his own eye to be forced out, sooner than relinquish his hold. Another, who was wounded, feigned death, keeping a knife ready to strike one more fatal blow. My informer said, when he was pursuing an Indian, the man cried out for mercy, at the same time that he was covertly loosing the bolas from his waist, meaning to whirl it round his head and so strike his pursuer. “I however struck him with my sabre to the ground, and then got off my horse, and cut his throat with my knife.” This is a dark picture; but how much more shocking is the unquestionable fact, that all the women who appear above twenty years old, are massacred in cold blood. When I exclaimed that this appeared rather inhuman, he answered, “Why, what can be done? they breed so!”
Text from Project Gutenberg, public domain in the United States.