On Valentine’s Day, every February 14, loving couples kiss each other and swear fidelity to each other. And the other animals? Are they kissing? Are they loyal and monogamous?
Loyalty is not natural! Polygamy is the rule, and first of all for the males who produce millions of spermatozoids. Multiplying partners means ensuring the genetic diversity of one’s offspring.
“ Everything happens as if evolution had favored the diversity of sexual behaviors, because this sexual diversity maintains the diversity of the world, the ecological diversity, specifies Thierry Lodé, professor of evolutionary ecology at the University of Rennes-1, specialist in animal sexuality. A male who copulates with many females can have many offspring, so there is an interest for him to copulate with several females. And the female, by copulating with many partners, can multiply the diversity of her litters. »
As we have understood, monogamy is the exception among animals. Only 3% of known species on the planet are monogamous. It’s a little more for mammals, 9%, and a lot more for birds, 90%, because it takes two to hatch eggs and look for food.
Breaches of the love contract
There is an exclusive monogamy, until death, for rare species, lovebirds, or swans. But even among reputedly loyal animals, there are breaches of the rules. “ In the chaffinch, once the usual male has left, the female will find a male who is often the neighbor in the corner, says Thierry Lodé. And as the male who left went to copulate with another female, it gives broods that are rarely above 40% monogamous; most often there are brothers and sisters who come from another father or another mother. »
Where does monogamy come from? The species that practice it have found an evolutionary interest in it. It is also very often suffered. “ The more difficult it is to meet another partner, the more individuals will tend to keep the one they have, explains Thierry Lodé, author of a Natural history of amorous pleasure (Editions Odile Jacob). And then the second criterion of monogamy is the degree of jealousy of the two individuals. The male carefully watches the female so that she does not try to look elsewhere and so that she cannot produce offspring that are not his. But in any case, there is always cheating… The very essence of this monogamy is that individuals make strong breaches of their contract. » Any resemblance to humans is purely coincidental. Valentine’s Day or not, humans are animals like any other.
THE QUESTION
“My neighbor’s dog kisses her with his tongue… Is that love?”
Hopefully it’s not rage! It is above all a question, for the dog, of socializing. We talk about social smell. This is the reason why some animals kiss each other “on the mouth”, because there is, in the saliva, information on the immune system of its partner. We exchange our saliva in mammals (mice, dogs, squirrels…) to find an immune system that is the most different from ours. This is why, in love, opposites attract.