Friday, March 27, 2015

Weaners

From this month's column in The Cambrian:

The beach at Piedras Blancas is quiet in March and April. Mostly weaners sleeping. Between naps, they go into the water, to practice holding their breath and learn to swim. As the days pass, they spend more time in the water, swimming and diving, until they are ready to launch into their first migration.
The weaner in the middle is losing his back natal coat.
Perhaps it’s an evolutionary disconnect, but they are unable to swim when they are born, despite the fact that they will ultimately spend most of their lives deep under water. When they are born, they are in danger of actually drowning if they are washed out to sea on a high tide. As they mature, they will spend eight to 10 months a year diving continually to 1,000 feet and deeper.

By March, they have been weaned from nursing and gaining weight — hence the term “weaners.” As they sleep on the beach and cavort in the surf, their metabolism is changing. They don’t have anything to eat on the beach. They spend the next eight to 10 weeks without food, living off that blubber. Their bodies convert some of it into muscle. They also increase the amount of blood and the oxygen-carrying capacity of their muscles, important adaptations to allow them to dive deep. The black coats they were born with are replaced with lighter tan and silver coats.
The young black weaner will soon molt to a lighter coat like his brothers.
At some point, each of the weaners feels the unknown call of the sea, and enters the water to begin its first migration. They may not get all the way to Alaska this first year, but they somehow know where to go. A few wash up on local beaches and are rescued. They will get supportive feeding until they are able to take on the ocean for themselves, then be set free.

About half never return, part of the cycle of life. Those that aren’t able to catch enough prey starve, and others become prey themselves. The circle of life.

Those that succeed will find their way back to island and mainland beaches along the West Coast in September. About three-quarters return to the beach where they were born.

A few adult bulls remain on the beach, sleeping and resting from the rigors of the three-month breeding season. Soon they will join all those that have already left, migrating up to Alaska to gorge on fish and squid, and gain weight for the coming year. There are always a few stragglers. Biological systems are usually distributed as a bell-shaped curve, with some early, some late and most in the middle.
This bull is thin at the end of the breeding season.
Watch for whales
Look beyond those sleepy weaners for whale spouts in the open ocean. Gray whales are migrating from their breeding and calving grounds in Baja California north to their feeding grounds in the Arctic from March through May.

Mothers and their calves swim close to shore during the northward migration to avoid orca attacks.
By staying close to the surf line, they take advantage of the pounding surf to camouflage them.
The shallow water also helps protect them, since orcas attack from below. If orcas are around, gray whales will come right up into the rocks and stay still to avoid detection.

Whale scientist Wayne Perryman monitors the whale count from the Piedras Blancas Light Station.
In 2014, he and his team counted 431 calves, the fourth-highest total in the 21 years that he’s been doing it.

Read more here: http://www.sanluisobispo.com/2015/03/25/3555959/weaners-elephant-seals.html#storylink=cpy

Monday, February 23, 2015

Weaners

Life is pretty easy for weaners. Mostly, they sleep on the beach.
these two are still losing their black newborn coats. They shed the black fur when they wean and acquire the brown, tan and silver of juveniles.
The weaners sleeping around this adult bull have mostly acquired their new coloration. This male looks pretty good but many are very thin. They've spent three months on the beach without food. Good thing they were fat to start with.
This one definitely shows the effect of long months without food.

Beautiful beach weather, although we need rain. Lots of whales traveling through, too.



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. 

Read more here: http://www.sanluisobispo.com/2015/01/21/3452936_beachmasters-elephant-seals.html?rh=1#storylink=cpy

Tuesday, January 6, 2015

Pup season in full swing!

Plenty of pups on the beach now! Here's my column on the subject from this week's Cambrian:

December brings the elephant seal bulls to the beach. Splashing and bellowing, they challenge each other and fight to establish who is dominant. The top seals, beachmasters, will get to breed with the females later.
This fellow arrives on the beach.
 These ocean giants started arriving from their feeding grounds in the North Pacific along the Canada and Alaska coast in late November. The pregnant females start arriving in December, landing on the beach one by one. They’ve been feeding and are ready to deliver their pups. The first of the season was born Dec. 12. Several other pregnant females are in the vicinity, a seal maternity ward.
By the time you read this, their pups will be born. More than 5,000 pups were born in the Piedras Blancas rookery last season.

Males challenge each other frequently. Those on the second rung of males, subdominant, loiter around the edges of the herd of females gathered on the beach. Occasionally, one will sneak in along the edge, looking for the main chance. The senior beachmasters maintain order through constant vigilance. Less dominant males annoying the new mothers stay aware of the alpha bull.

When he opens his eyes and gives them the stink-eye, they scatter.

Females will continue to arrive through February. The mothers give birth to their pups on the beach shortly after they arrive. Pups aren’t exactly helpless, but they’re skinny. They nurse avidly, gaining more than 200 pounds in a month. Their mothers don’t eat during that time, so they slim down as their pups fatten.

This newborn gives himself a scratch.
As their motherly duties wind down after about a month of lactation, the females come into estrus (heat) and are receptive to breeding. That’s what the bulls have been waiting for. One by one, the females return to the ocean to eat, gain weight and have another pup next year.

Male elephant seals have occasionally beached themselves on Hearst State Beach at San Simeon Cove, but last year was the first time females came and had their pups there. Females generally return to the same beach to give birth, so they are expected to show up again. San Simeon is a popular beach with humans, so it puts the issue of getting along with wildlife front and center.

The beach is under overlapping jurisdiction of the National Oceanic and Atmospheric Administration and California Department of Parks and Recreation. Supervising Ranger Lisa Remington is planning ahead for the arrival of seals on the beach. A male is already in residence at the south end location where four or five females had pups last year.

The Marine Mammal Protection Act is a federal law that prohibits anyone doing anything to harass or harm the seals. State Parks’ codes also protect the seals, and local Parks Superintendent Nick Franco has issued an order to stay at least 100 feet from the seals. The district will post informational signs at Hearst Beach, Arroyo Laguna and the Piedras Blancas motel.

“Those are the places drivers first see the seals,” Remington said. “We want them to know, for the best viewing, just keep going. We’re very proactive about educating the public.”

Remington is recruiting new Elephant Seal Ambassador docents to direct eager visitors to the Piedras Blancas viewpoint, where visitors have a better view. And both seals and people are safer.

“Part of the mission of State Parks is to balance resource protection with recreation,” she said. “The restrictions aren’t arbitrary. Everything goes back to finding that balance.”

Docents will get eight hours of training, scheduled for the first week of January, before going out to meet the public at Hearst State Beach. Cal Poly interns from the Coastal Discovery Center and the Tourism and Recreation Department will join the ranks. Contact Robyn Chase (805) 400-8531 or Robyn.Chase@ parks.ca.gov to sign up. 

Read more here: http://www.sanluisobispo.com/2014/12/24/3413467/piedras-blancas-elephant-seal.html?sp=/99/177/183/429/887/#storylink=cpy

Wednesday, December 31, 2014

Pups

This mother looks at her newborn. They hadn't quite gotten nursing organized by the time I left on Monday.

Monday, December 22, 2014

High tides

Two seals got into the viewing area last week. Thanks to Susan Garman for sending the photos from the Marine mammal Center Rescue Team. Here's the tv report.
This bull obligingly lies by an interpretive sign.

Difficult for visitors to get out on the boardwalk with this guard in place.

The high tides and lack of sand have made the north part of the beach inhospitable to mothers and pups. This morning, it was completely inundated by waves.
Waves lap against the base of the cliffs, leaving little safe space for pups. Pups can't swim until they are three months old, and are in danger of drowning.

It didn't bother this massive bull, but the female next to him better find a better place to have her pup.


That nose grows throughout his life. He's certainly a senior bull.

At least two new pups have joined the first one, born over a week ago. This sectionof the south beach has remained above the high tide line. The mothers are lying on the ocean side of their pups. I like to think they are protecting them.


Tuesday, December 16, 2014

First pup!

This pup was born December 12. That's early. Usually, the first birth is around December 20. He's already a great attraction at Piedras Blancas.
Some of the young males seals approached her, eager to breed, even though she's a month from being receptive to them. The senior bull nearby, apparently sleeping, nevertheless, kept an eye on the situation. She chased them off but he raised an eyelid and looked over, and they settled down.

Soon two other pregnant females joined her in the maternity ward.