Thursday, January 18, 2018

Molting

Ella was difficult to find this morning, but I located her rotund form close to the bluff. She's out of the fray of newborns and their mothers here. She's molting the blackcoat she was born with, for her first mature coat.


She'll have countershading, dark on her back and light on her underside. It's an ocean camouflage that will help her blend in with the dark depths when predators above look down at her, or the light sky when those below her look up.

Between a high tide and high surf warning, the beach was inundated this morning. The seals were flustered, trying to get away from the waves, but not very effective in doing anything about it.
More rain is expected tonight. The rain isn't really a problem, but it does pool on the beach under the culvert pipes that drain from the ranch.


Some found dry land and rest, even in difficult times.


Monday, January 15, 2018

Ella is weaned

Diana Kramer, director of The Marine Mammal Center San Luis Obispo facility, which is actually in Morro Bay, Was out at Piedras Blancas and posted this report:

Today we found Ella who weaned this weekend! We were pretty confident it was her (or him) because she was right by post nine as usual and the only big fat weaned pup! 



She looks great, nice and robust and was enjoying resting on the beach. You can really see her size in the pic with the smaller pup in the background!  


Some elephant seal drama in her corner, though, with one big male lumbering through chased by another male. The losing male woke her up from her nap with a big bop to the head as he scooted through, but she made it through ok! 



It looks like Ella is aiming to be a super weaner, because we caught her (or him) checking out some other females to see is if she could get away with stealing some milk!

Tuesday, January 9, 2018

Rain

A major storm arrived in Piedras Blancas overnight. Rain doesn't faze the seals particularly. Ella is doing well.

The beach is now full of adult seals and pups. Some have commented that they seem late this year. I've looked at photos from previous years and am not sure there is much difference. Perhaps USGS Wildlife Biologist Brian Hatfield will have a report later on the timing of this year's birth season.

Thursday, January 4, 2018

Aggression

The most dominant male, the beachmaster, gets breeding priority, but in these early days before the females come into estrus,  less dominant males are causing uproar among the mothers. Some are attempting to breed with the new mothers, even though they have not come into estrus yet. Their pups are small, and easily overlooked as the males attempt to bully a female into mating.

Kathleen Curtis made this video of a male harassing a mother.

Dominance reduces aggression on the beach, by sending aggressive but less dominant males packing. the females come into estrus at the end of lactation, and become willing to breed. None of the females has finished nursing yet, so none are yet in estrus.

Patrick Robinson, director of the Ano Nuevo Island Reserve, said as the females come into estrus, the dominant beachmasters should become more vigilant.

Pups can be killed, in the rough and tumble as the male tries to mate and the female tries to escape. The male may kill the pup by biting its head. The pup may be separated from its mother, which is the most common cause of pup death. Struggling with a bigger male uses the mother's limited store of energy (blubber), which she needs to feed her pup.

It's a tough life down there on the beach. Despite all that, over 90 percent of the pups at Piedras Blancas survive to be weaned.

Tuesday, January 2, 2018

Bulking up

On New Year's Day, I went to check on Ella. With a dozen or more newborn pups close by, I thought I might have lost track of her. No problem! She is far and away the fattest, most grown pup out there.

She's getting a nice crease at the back of her neck, an indication of good store of blubber.

I can't tell whether Ella is a male or a female. males nurse an average of a day longer than females and gain more weight. Males get teeth sooner than females, too. Ella probably has most of the 30 teeth she will get by the time she is weaned.

Ella has a solid relationship with her mother, but several pups nearby were separated from any nearby females. Maternal-pup separation is the most common cause of pup death, so it's a concern to see these pups alone.
Pups don't always stay with their own mothers. In one study only 22 percent of the pups nursed only on their own mothers. The rest all nursed on another female, at least occasionally. If a pup dies, the bereaved mother may adopt a separated pup, or even try to steal another mother's pup. At Piedras Blancas, over 90 percent of pups born on the beach survive to be weaned.

This youngster was doing well.


New Year's Day brought a rich migration of food fish to the waters. The waves boiled with dolphins skimming and leaping. Flocks of pelicans and gulls circled and dove into the feast. It was the most boisterous feeding event I've ever witnessed. Some landed on the water, and appeared to scoop up prey from there.



The viewpoint has been crowded with visitors during the holiday season. I hope they have come away with a new appreciation of the importance of protecting the oceans.

Tuesday, December 26, 2017

Milk

Ella is getting bigger every day on her mother's milk. Elephant seal milk starts out watery, at 12 percent fat, and gets progressively thicker as the days go on. Ella will go from her birth weight of 65-80 pounds to about 300 pounds in a month.

Elephant seal mothers do not eat while they are lactating and feeding their pups. Every nutrient that goes into the pup comes directly from her. Her body metabolizes its blubber to make milk. More concentrated milk, with less water, means that much less her body has to produce. By the end of the month of lactation, the milk may be as much as 60 percent fat, making it more like mayonnaise than fluid.

Cow milk is naturally about 3.5 percent fat. Less fat in milk is often desired, and two percent, one percent and fat-free milk are available commercially. Human milk is about 4.5 percent fat.

Ella's mother is getting visibly thinner. She will lose about a third of her body weight by the time she weans her pup.

Saturday, December 23, 2017

Filling out

Ella continues to do well. She's plumper every day.


Two more pups were born during the night, bringing the total to seven. One mother was determined to have two pups to herself. She threatened, and even fought, with the other mother.

My observation is that confusion like this eventually sorts itself out. However, maternal-pup separation is the most frequent cause of pup death. Disputes like this can have serious outcomes for pups.