Wednesday, January 28, 2015

Beachmasters rule!

January at the Piedras Blancas elephant seal beach is a constant soap opera. Newborn pups are born, beginning their saga. Adult male bulls vie with one another for dominance, the key to the big prize of mating with the females. Mothers squabble over territory and, sometimes, over pups.

Females arrive daily, and births happen frequently. More than 5,000 pups will be born in the rookery this year, and anything can happen.

Some pups bond with attentive mothers and suckle their way to 300 pounds.

But pups sometimes get separated from their mothers, who may lose track of them. The mother may be distracted by another mother or pup coming too close for her comfort. The mother may have to scoot down the beach to escape a bull thundering across the sand to face a challenger.

Witnessing a birth is a high point for visitors. Many births occur within easy viewing range, but it’s not always easy to predict who will have a pup next. Docents try to point out possible nativities, but it’s never a sure thing. Even if a female is contorting herself in ways that suggest she’s straining to give birth, the arrival may be hours away.

Once birth begins, it’s over within minutes. Look for a female digging out trenches on each side as she shovels sand into the air. A burst of water as the amniotic sac breaks, then a nose or flippers slipping out. Pups may be born head or flippers first.

Gulls indicate when a birth has occurred, swarming around to eat the afterbirth. They clean it all up. For them, it’s protein-rich food, part of the biological cycle.

Bulls presiding over a harem of females with their pups are called beachmasters. Perfect name! See them reclining in the midst of the crowd, their long noses flopped in the sand.

Less dominant bulls sneak around the edges, looking for the main chance with one of the girls. It seldom works — the females won’t mate until they come into estrus (heat) at the end of lactation. They bark their objections, which soon brings the wrath of the beachmaster down on the interloper.
Somehow, the less dominant bulls never get discouraged. They continue to hang around and make advances, no matter how often they get chased.

Most dominance interactions consist of one bull challenging another by advancing toward him. One or the other backs down and moves away.

You’ll see a lot of that on the beach, as one bull moves forward, another moves toward him, then a third bull moves toward the territory vacated by the challenger.

Occasionally, displacement doesn’t settle it, and the bulls come to real blows.

They bump their massive chests and rip and tear with long canines at each other’s chest shields — the pink calloused skin around their necks. 

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