Why "stupid" Kerguelen cats

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Between 1952 and 1956, sailors left several cats on the Kerguelen Islands. Cats are well established here, they were wild and multiplied in such quantity that a threat of complete disappearance of local birds arose. So the basis for solving an interesting question arose: how did the domestic cats affect the way of life of their wild ancestors?

Previously, it was believed that the animal that returned to the wild life, the intellect develops. Why? And the fact is that domestication, according to many researchers, has a great impact on animal behavior, as well as on their structure: animals muzzle shortened, skull volume decreases, brain weight decreases by 20-30 percent. Living under the protection of a person, a pet has no need to take care of food and defend itself from enemies, it does not need to experiment, and therefore, to develop their mental abilities. In this respect, the pet is inferior to its fellow man in a species that lives in natural conditions.

And how will it behave if it returns to the original way of life, accidentally or intentionally finding itself in some geographically isolated place, for example, on the islands, as happened with cats?

Studies of this kind, unfortunately, are few. They are difficult to conduct and verify. It is necessary to have sufficient confidence that the former domestic animals do not interbreed with native wild species, which, of course, would change the results. Nevertheless, even the available studies made it possible to conclude that the intellect of a number of domestic animals (donkeys, pigs, rams, rabbits) that have returned to the way of life of their wild ancestors is developing.

As for the cats, the results of the studies were extremely controversial. A cat, Konrad Lorenz writes, is an animal that is wild, and the fact that it came to get warm near our hearth was, in the final analysis, a mere accident.

Indeed, the domestic cat has its own territory, which is jealously guarded, during the hunting for mice and sparrows, the normal behavior of the predator manifests, its "family affairs" proceed according to the laws characteristic of its species (the battle of males, "singing", pursuit). We can say that there is no or almost no difference between the way of life of a domestic cat and a wild cat. It would seem that there should be no difference in their behavior.

Everything would be logical, if not for the case on the Kerguelen Islands. Measuring the skulls of these feral cats showed that they differ both in size from the skulls of wild and domestic cats. Return to the "wild" life was marked for them by a decrease in the volume of the skull by about 12.5 percent. Meanwhile, the rabbits that were released in 1974 on the same archipelago developed as it was noted before, that is, they became "smarter".

Several hypotheses have been advanced to explain such a strange deviation from the laws of nature. The entire population of cats on the Kerguelen Islands developed from a dozen or a little more of the founders: the genetic set, characteristic of the species, was not transmitted in its entirety, and subsequent generations were deprived of a number of characteristics. So, for example, the color was not updated - all Kerguelen cats have the same skin. The arrival of "fresh blood", taking into account the geographical isolation of the islands, is impossible, and the consequence of this is incest and degeneration.

On the other hand, cats in the archipelago have neither enemies nor competitors. There is a lot of food, and it's easy to get. The abilities inherent in the mind do not, therefore, need to manifest themselves. And the Kerguelen cats "fell asleep on their laurels".