All the bushes in the vicinity of the town are inhabited by a kind of Guinea pig (Cavia Cuttleri, King). These animals are exceedingly numerous. After sunrise and towards evening, they leave their lurking places and play about in the grass. Upon the whole they are not shy, and they allow people to approach them pretty closely. The natives call this little animal the Cui del Montes, and they believe it to be the progenitor of the tame Guinea pig. This notion is, however, quite erroneous.
Along the whole of the Peruvian coast there is found a small animal of the lizard kind, of which the natives are very much afraid. They call it the Salamanqueja. It lives in the fissures of walls, and is sometimes seen creeping along the lime plaster of houses. Its bite is believed to be mortal. From the descriptions given of this animal, I was curious to see it, and I commissioned some persons to procure me one. At last, an Indian brought me a specimen very much crushed, and I found that I had already got several of them in my collections. I now obtained more of them, and the natives beheld me with astonishment carrying them alive in my hand. Of the Salamanqueja there are two species, the Diplodactylus lepidopygus, Tsch., and the Discodactylus phacophorus, Tsch. They are nearly related to each other, being only distinguished by one species having an orifice in the thighs, serving as a passage for an issue from a gland which secretes a very acrid fluid. This little animal never bites; but it is possible that the fluid by touching a fresh wound, or scratch, may cause very serious consequences.
To the south of Yca there are some large cotton plantations; the most considerable of which belong to Don Domingo Elias. The cotton for exportation is shipped at the port of San Nicolas. Many experienced captains of ships declare the bay of San Nicolas to be the safest and best along the whole of the western coast of South America.
The Quebrada of Huaitara, which stretches to the east of Yca, is the principal channel of communication between this part of the coast and the rich mountain provinces of Jauja and Huancavelica, and from the latter places to Ayacucho and Cosco.
Opposite to Pisco and Chinca there is a group of small islands, of which the largest, Sangallan, is six English miles distant from Pisco. These islands have of late years become celebrated on account of the great quantity of guano that has been exported from them.
Guano (or according to the more correct orthography, Huanu)[51] is found on these islands in enormous layers of from 35 to 40 feet thick. The upper strata are of a greyish-brown color, which lower down becomes darker. In the lower strata the color is a rusty red, as if tinged by oxide of iron. The Guano becomes progressively more and more solid from the surface downward, a circumstance naturally accounted for by the gradual deposite of the strata, and the evaporation of the fluid particles. Guano is found on all the islands, and on most of the uninhabited promontories of the west coast of South America, especially in those parts within the tropics. I have often been assured that beds of Guano several feet high, covered with earth, are found inland at some distance from the sea; but I never met with any, and I have some doubt of the correctness of the statement. If, however, these inland strata really exist, I am inclined to believe that they can only be found on hilly ground; and in that case they afford strong evidence of a considerable elevation of the coast.
Guano is formed of the excrements of different kinds of marine birds, as mews, divers, sheerbeaks, &c.; but the species which I can name with more precision are the following:—Larus modestus, Tsch.; Rhinchops nigra, Lin.; Plotus Anhinga, Lin.; Pelecanus thayus, Mol.; Phalacrocorax Gaimardii, and albigula, Tsch. (Pelecanus Gaimardii, Less., Carbo albigula, Brandt), and chiefly the Sula variegata, Tsch.
The immense flocks of these birds as they fly along the coast appear like clouds. When their vast numbers, their extraordinary voracity, and the facility with which they procure their food, are considered, one cannot be surprised at the magnitude of the beds of Guano, which have resulted from uninterrupted accumulations during many thousands of years. I kept for some days a living Sula variegata, which I fed abundantly with fish. The average weight of the excrement daily was from 31⁄2 to five ounces. I have no doubt that when the bird is in a state of freedom the weight must be much greater, for these birds are constantly plunging into the sea, in order to devour the fishes which they find in extraordinary masses around all the islands. When an island is inhabited by millions of sea-birds, though two-thirds of the guano should be lost while flying, still a very considerable stratum would be accumulated in the course of a year.
The marine birds nestle on the uninhabited islands, or on rocks near the shore; but they never settle on the flat beach, or any place distant from it inland. On this fact, I ground my conjecture that those beds of guano in the interior, which may have been removed from the shore by important elevations of the coast, are to be found only on hills.
During the first year of the deposit the strata are white, and the guano is then called Guano Blanco. In the opinion of the Peruvian cultivators, this is the most efficacious kind. It is found in the Punta de Hormillos, on the islands of Islay, Jesus, Margarita, &c.