Monday, December 8, 2014

Changing of the guard

My monthly column for The Cambrian:

Plenty of juvenile seals are still on the beach this week, but the adult male bulls will start arriving any day now. The youngsters, refreshed by a month or more on the beach, will head back into the ocean and leave the beach to the bigger seals.
Two six-year-old seals square off.
Young males, 6 years old and younger, tussle with one another in the water and rest on the beach. They join females, 1 to 3 years old — not yet old enough to breed — on the sand. You can tell how old by how well developed that elephant-like nose is. Five-year-olds are just getting a bend. That bend grows into a noticeable trunk in the following year. It grows throughout the seal’s life, so senior seals have very impressive ones, indeed. Technically, it’s called a proboscis.

November is the calm before the ruckus of the birthing and breeding season. Bigger, older, more experienced bulls soon stake their claims on the beach. Only the most dominant males get to breed, so there’s a lot at stake. Every male wants to be a beachmaster.

Dominance interactions range from displacement to outright battles. The less dominant seal is displaced when he moves away from his more dominant rival. That’s typical. One seal challenges, the other moves away, that settles it. When that doesn’t satisfy the bulls involved, they will battle each other.

Richard Condit, staff scientist at the Smithsonian Tropical Research Institute, has studied Northern and Southern Elephant Seal populations. He estimates there are around 215,000 total Northern Elephant Seals.

He presented his information to Friends of the Elephant Seal docents in November. Counting seals is tricky, but good photos of the Piedras Blancas rookery during January and February, when the pups are being born, help. He counts the females even when he can’t see the pups. Counting the successfully weaned pups is easier.

“They are all just sitting there in a pile waiting to be counted,” he said. “Not many animals will do that.”

FES docents in their distinctive blue jackets are available every day at the viewpoint. Ask them for more information about how many seals there are and how long they live.

Read more here:

No comments:

Post a Comment