Friday, 6 March 2015

More observations on dogs and goats from the 16th century

This post descends from discovering in an earlier post (see here) that Malthus (1798. Essay on the Principle of Population) had an anticipator in Townsend (1786. Dissertation on the Poor Laws by a well-wisher to mankind) and from realising that Townsend's example of a case of natural selection was based on a real observation (see previous post) on an island of the Juan Fernández archipelago made by Don Antonio de Ulloa (1758. Voyage to South-America by Don George Juan and Don Antonio de Ulloa, both captains of the Spanish Navy. Vol. II. London: Davis & Reymers).

The whole story now seems to turn into a series of prequels with interesting ecological observations made by preceding explorers. This post will be about the expedition of George Anson (1748. A Voyage Round the World in the years 1740 to 1744. London: John and Paul Knapton) compiled by Richard Walter, the chaplain of his Majesty's ship in that expedition, the Centurion. This expedition came before that of Juan and Ulloa but after the privateer Alexander Selkirk has been cast away there in 1704. After his rescue, Selkirk's story probably became one source of inspiration for the Robinson Crusoe novel. The two main Islands of Juan Fenrández are now called Alejandro Selkirk (formerly Más Afuera), though Selkirk never was on this island, and Robinson Crusoe Island (formerly Más a Tierra) respectively.

The passage on goats and dogs begins at page 169, with an account of an unintended capture-release-recapture experiment started by Selkirk:
"It remains now only that we speak of the animals and provisions which we met with at this place. Former writers have related, that this Island abounded with vast numbers of goats, and their accounts are not to be questioned, this place being the usual haunt of the buccaneers, and privateers, who formerly frequented those seas. And there are two instances; one of Musquito Indian, and the other of Alexander Selkirk a Scotchman, who were left by their respective ships, and lived alone upon this Island for some years,and consequently were no strangers to its produce. Selkirk, who was the last, after a stay of between four and five yeas, was taken off the place by the Duke and Duchess Privateers of Bristol, as may be seen at large in the journal of their voyage: His manner of life, during his solitude, was in most particulars very remarkable; but there is one circumstance he relates, which was so strangely verified by our own observation, that I cannot help reciting it. He tells us, among other things, as he often caught more goats than he wanted, he sometimes marked their ears and let them go. This was about thirty-two years before our arrival at the Island.Now it happened, that the first goat that was killed by our people at their landing had his ears slit, whence we concluded, that he had doubtless been formerly under the power of Selkirk. This was indeed an animal of a most venerable aspect, dignified with an exceeding majestic beard, and with many other symptoms of antiquity. During our stay on the Island, we met with others marked in the same manner, all the males being distinguished by an exuberance of beard, and every other characteristick [sic] of extreme age.
But the great number of goats, which former writers described to have been found upon this Island, are at present very much diminished: For the Spaniards being informed of the advantages which buccaneers and privateers drew from the provisions which goat-flesh here furnished them with, they have endeavoured to extirpate the breed, thereby to deprive their enemies of this relief. For this purpose, they have put on shore great numbers of large dogs, who have encreased apace and have destroyed all the goats in the accessible part of the country; so that there now remain only a few amongst the craggs and precipices, where the dogs cannot follow them. These are divided into separate herds of twenty or thirty each, which inhabit distinct fastnesses, and never mingle with each other: By this means we found it extremely difficult to kill them; and yet we were so desirous of their flesh, which we all agreed much resembled venison, that we got knowledge, I believe, of all their herds, and it was conceived, by comparing their numbers together, that they scarcely exceded two hundred upon the whole Island." (Anson 1748, p. 169-171)