The females of elephant seals como into heat in spring and begins the reproductive stage. The males start fighting to the death to defend their harem.
A change in the weather marks the arrival of the southern Spring, and the peninsula receives one of the last rains that will fall here in the rest of the year. The sea lions have not yet moved to their breeding grounds. They are in the south of the peninsula, and also threatened by the most feared of all visitors.
This time, however, their target is not the sea lions, but relatives of theirs who have already begun breeding.
The female elephant seals are now in heat. The males, who had already established their territories and harems in August, must again defend them.
The young are repelled with ease, but when the competitor is an adult, a terrible clash is inevitable.
With their sharp teeth, the males try to wound their opponent on the neck or head.
And this is the victor’s spoils: an entire harem of fourteen females that the defending male had managed to collect as the result of innumerable fights. A prize well worth the effort.
On this occasion, he has again been able to retain control over his harem, but this will not be the last time he will have to fight. In the course of the month, each of the females will come into heat, and other pretenders will seek to conquer his fiefdom.
After the battle, the victor exercises his rights over the females he owns.
The female has little say in matters of reproduction. The master of the harem, aroused by the combat, assails his mate, immobilising her beneath his two thousand kilos in weight, and copulates. The difference in size makes any attempt at resistance futile.
During the breeding season, the male does not eat, and so, after ten weeks of fasting and intense exercise, his weight can drop by as much as 40%.
For the time being, however, his strength remains intact, and he demonstrates it by mounting all the females in the harem as they come into heat.
The females are not all receptive at the same time. The last ones to arrive on the peninsula are not yet ready to mate. They still have three weeks of breast-feeding, during which time the fur of the young will change from black to grey, and they will put on weight. At birth, they weigh 45 kg., which will rise to 250 kg. at the end of this period.
The females also do not eat during this time, and so if they have not accumulated sufficient reserves they will not be able to provide their young with enough nutrition to guarantee their survival.
As the breeding season of the elephant seals comes to an end, that of their close relatives, the sea lions, begins.
The males arrived around the middle of December in order to stake out their territories and wait for the females. Since then, there have been constant fights among them, though generally threats are enough to dissuade the weaker one from any attempt to fight.
The females arrived shortly after and, after giving birth, they are again ready to breed. They can copulate from 1 to 3 times, and not always with the same male. They all arrive at the same time, and the breeding season can last for two months. This is a severe test for the males, who during all this time do not eat and hardly sleep. Gradually, their strength diminishes, and competitors prowling around the harems manage to escape their vigilance and copulate with a female, even if it is in secret and beneath the water.