Travels on the Amazon

by Alfred Russel Wallace

Alligators of three or four distinct species abound in the Amazon, and in all its tributary streams. The smaller ones are eaten by the natives, the larger often devour them in return. In almost every village some persons may be seen maimed by these creatures, and many children are killed every year. The eggs of all the different kinds are eaten, though they have a very strong musky odour. The largest species (Jacare nigra) reaches a length of fifteen, or rarely of twenty feet.

The most interesting and useful reptiles of the Amazon are, however, the various species of fresh-water turtles, which supply an abundance of wholesome food, and from whose eggs an excellent oil is made. The largest and most abundant of these is the Tataruga, or great turtle of the Amazon, the Jurará of the Indians. It grows to the length of three feet, and has an oval flattish shell of a dark colour and quite smooth; it abounds in all parts of the Amazon, and in most places is the common food of the inhabitants.

In the month of September, as soon as the sandbanks begin to be uncovered, the females deposit their eggs, scraping hollows of a considerable depth, covering them over carefully, smoothing and beating down the sand, and then walking across and across the place in various directions for the purpose of concealment. There are such numbers of them, that some beaches are almost one mass of eggs beneath the surface, and here the Indians come to make oil. A canoe is filled with the eggs, which are all broken and mashed up together. The oil rises to the top, and is skimmed off and boiled, when it will keep, and is used both for light and for cooking. Millions of eggs are thus annually destroyed, and the turtles have already become scarce in consequence. There are some extensive beaches which yield two thousand pots of oil annually; each pot contains five gallons, and requires about two thousand five hundred eggs, which would give five millions of eggs destroyed in one locality.

But of those that remain, a very small portion are able to reach maturity. When the young turtles issue from the egg, and run to the water, many enemies are awaiting them. Great alligators open their jaws and swallow them by hundreds; the jaguars from the forest come and feed upon them; eagles and buzzards, and the great wood ibises attend the feast; and when they have escaped all these, there are many ravenous fishes which seize them in the stream.

The Indians catch the full-grown turtles, either with the hook, net, or arrow. The last is the most ingenious method, and requires the most skill. The turtle never shows its back above water, only rising to breathe, which it does by protruding its nostrils almost imperceptibly above the surface; the Indian's keen eyes perceive this, even at a considerable distance; but an arrow shot obliquely would glance off the smooth flat shell, so he shoots up into the air with such accurate judgment, that the arrow falls nearly vertically upon the shell, which it penetrates, and remains securely fixed in the turtle's back. The head of the arrow fits loosely on to the shaft, and is connected with it by a long fine cord, carefully wound round it; as the turtle dives, they separate, the light shaft forming a float or buoy, which the Indian secures, and by the attached cord draws the prize up into his canoe. In this manner almost all the turtles sold in the cities have been procured, and the little square vertical hole of the arrow-head may generally be seen in the shell.

Besides the great tataruga (Podocnemis expansa), there are several smaller kinds, also much used for food. The Tracaxa (Emys tracaxa, Spix) and the Cabeçudo (E. macrocephala, Spix) have been described by the French naturalists, Duméril and Bibron, as one species, under the name of Peltocephalus tracaxa; but they are quite distinct, and though their characters are perhaps not easy to define, they could never be confounded by any one who had examined them in the living state. They are found too in different localities. The tracaxa is abundant in the Amazon, in the Orinooko, and in the Guaviare, all white-water rivers, and very scarce in the Rio Negro. The cabeçudo is very abundant in the Rio Negro and in the Atabapo, but is not found in the Guaviare or the Amazon, appearing to be confined to the black-water streams. I obtained ten distinct kinds of river tortoises, or Chelydidæ, and there are also two or three kinds of land-tortoises inhabiting the adjacent district.

As might be expected in the greatest river in the world, there is a corresponding abundance and variety of fish. They supply the Indians with the greater part of their animal food, and are at all times more plentiful, and easier to be obtained, than birds or game from the forest.

During my residence on the Rio Negro I carefully figured and described every species I met with; and at the time I left fresh ones were every day occurring. The soft-finned fishes are much the most numerous, and comprise some of the best kinds of food. Of the Siluridæ I obtained fifty-one species, of Serrasalmo twenty-four, of Chalceus twenty-six, of Gymnotus ten, and of spinous-finned fishes (Acanthopterygia) forty-two. Of all kinds of fishes I found two hundred and five species in the Rio Negro alone, and these, I am sure, are but a small portion of what exist there. Being a black-water river, most of its fishes are different from those found in the Amazon. In fact, in every small river, and in different parts of the same river, distinct kinds are found. The greater part of those which inhabit the Upper Rio Negro are not found near its mouth, where there are many other kinds equally unknown in the clearer, darker, and probably colder waters of its higher branches. From the number of new fishes constantly found in every fresh locality and in every fisherman's basket, we may estimate that at least five hundred species exist in the Rio Negro and its tributary streams. The number in the whole valley of the Amazon it is impossible to estimate with any approach to accuracy.

D. Insects.

To describe the countless tribes of insects that swarm in the dense forests of the Amazon would require volumes. In no country in the world is there more variety and beauty; nowhere are there species of larger size or of more brilliant colours. Here are found the extraordinary harlequin-beetle, the gigantic Prioni and Dynastes; but these are exceptions to the great mass of the Coleoptera, which, though in immense variety, are of small size and of little brilliancy of colour, offering a great contrast to the generally large-sized and gorgeous species of tropical Africa, India, and Australia. In the other orders the same rule holds good, except in the Hymenoptera, which contain many gigantic and handsome species. It is in the lovely butterflies that the Amazonian forests are unrivalled, whether we consider the endless variety of the species, their large size, or their gorgeous colours. South America is the richest part of the world in this group of insects, and the Amazon seems the richest part of South America. This continent is distinguished from every other by having a most extensive and peculiar family, the Heliconiidæ, of which not a single species is found in either Europe, Asia, Africa, or even North America (excepting Mexico). Another family, still more extensive, of exquisitely beautiful small butterflies, the Erycinidæ, is also almost peculiar to it, a few species only being found in tropical Asia and Africa. In both these peculiar families the Amazon is particularly rich, so that we may consider it as the headquarters of South America Lepidoptera.