Wednesday, April 27, 2022

Sealstack

April and May are the most crowded months on the beach at Piedras Blancas. All the adult females, over 5,000, plus juveniles of both sexes, arrive for their annual molt. It’s ideal seal watching for every possible variation in coat color and scientific markings.



No adult bulls, though. Some of the young males show signs of growing that distinctive nose, but they are at least two years away from adulthood. The mature bulls are on their post-breeding-season migration, foraging to regain the weight they lost. They may have gone as long as 120 days without food. Time to bulk up.

They feed along the continental shelf on the Canadian and Alaskan coastline. They will return in July and August, to molt their skin.

Molting

The expanse of brown, tan and gray animals looks indistinguishable at first, but let your eyes get accustomed to it. It’s like looking at jigsaw puzzle pieces, Gradually, contrasts emerge.

Shiny black seals just came out of the water. As they dry, their skin looks brown on their backs, tan on the underside. The seals undergo the process of a catastrophic molt once a year. As the old skin peels off, it reveals the new gray skin and brown coat beneath. The hairs of the coat just haven’t dried out and stood up yet. As they do, the coat acquires its brown color.



Compare how the molt happens on different seals. It starts around the eyes and other body orifices, and old scars. Some are pockmarked with scars from cookie cutter sharks, a small shark that bites, twirls around to take a distinctive circular plug of blubber, and leaves with its blubber meal.



They look ratty, but it’s normal. Seals arrive one by one on the beach, and start peeling off their skin within a couple of days. They spend about four weeks on the beach during April and May, so seals are at all stages of molting for the duration.

FES docents have samples of shed skin you can touch and handle. Clean and dry.

Delayed implantation

As females complete their molt, the embryo that started to grow back in January and February, when they mated after they finished nursing this year’s pup, now begins to develop. When they leave the beach this time, it will be for their long migration. They’ll be foraging in the ocean until January, when they return to the beach to have their pups.

Tags and marks

Cal Poly and UC Santa Cruz have research programs that involve identifying individual seals so that their movements to other beaches can be recorded. Look for marks and tags. If a blue-jacketed Friends of the Elephant Seal docent is around, report it to them. If not, take pictures and send them to tags@elephantsel.org. They’ll get back to you for additional information – when and where you saw the seal – and your re-sighting will be part of the database.

 


 

 

Sunday, March 27, 2022

Weaners prepare to migrate

Weaners balance blubber and muscle

Swim school workouts help

Weaners prepare to face their lives in the open ocean in March. They venture into the surf to practice diving, swimming and holding their breath. Watch a video on the Friends of the Elephant Seals YouTube channel.

The atmosphere on the beach is peaceful, following the drama of breeding season. A few bulls remain on the beach, resting up, unconcerned with the weaners.



The bulls are at their thinnest, having lived on their blubber for more than three months. The recently weaned pups are at their fattest.

Blubber into muscle

Feeding ended when their mothers left. Until they begin catching fish on their first migration, they rely completely on their blubber.

They take this time on the beach to exercise, improve their swimming skills in the surf and turn some of that blubber into muscle. They are more likely to be in the water at night, but you may see them splashing around during the day. Their life deep in the ocean will require them to hunt in the dark depths.

Balancing blubber and rest



Generally, bigger is better for elephant seals, but there’s a balance. Size, weight and blubber figure in dominance, staying warm, and having physical resources to survive. Pups need enough blubber to draw on after they stop nursing to launch them into success in the ocean. They need to dive and catch prey to feed themselves.

Blubber is buoyant, though. Fatter weaners struggle to dive to depth where they can hunt and feed.



Two scientists at UC Santa Cruz have followed adult females, “to better understand the behavior of a wild animal trying to find food while trying to avoid becoming food.” Roxanne Beltran and Jesse Kendal-Bar evaluated data from tracking devices. They found the females balance the need for food against the danger of sleeping, depending on how light it is.

During the light of day. the seals are at risk of being attacked by sharks. They are safer resting deep in the dark ocean depths during the day. Thin seals who need to put on blubber are more inclined to risk resting during the day, when it’s lighter, and spending more time feeding at night, when they don’t have to dive as deep to forage.

As they put on blubber, they are more inclined to rest at night, when they are safer. They are safer awake than asleep, but they have to sleep sometime.

The researchers call it the Lightscapes of Fear. They intend to use this insight to inform research on other, land-based, species.

Weaners are in danger during their first migration. Only half of them survive to return to the beach in September.

Stranded weaners

Underweight and exhausted weaners may strand on local beaches. If you see one on the beach, call the Marine Mammal Center operations center in Morro Bay at 415-289-SEAL (7325). They will send out a team to evaluate it and rescue it if necessary.

Sunday, February 20, 2022

Pups are weaned, moving to independence

 Pups wean to independence

Adult seals breed for next year’s pups

Many mothers have weaned their pups, who now rest in groups (pods) at the base of the bluff. They’re staying clear of the ruckus of breeding among the females who are still nursing and preparing for their short migration.



The mothers come into heat as nursing concludes. Bulls vie for breeding rights, sometimes coming to blows.

Beachmaster imposes discipline

The beachmaster, usually the biggest bull, rules the females in his section of the beach. Less dominant males are constantly looking for opportunities to breed females at the edge of the beachmaster’s influence. The dominance hierarchy helps reduce actual fighting. Bulls recognize each other’s unique vocalization, as if each one had a name. Bulls who have fought in the past don’t have to fight again to establish who is boss.



Weaners face the world

Pups are born with black coats, which help keep them warm. Being born on the California coast in December and January makes that important for pups who have little blubber when they are born. In that month of nursing, they gain about 200 pounds. Nicely rounded now in blubber, the pups molt their black coats for their first brown and tan coat. After molting, they are countershaded darker on their backs and lighter on their bellies, a form of ocean camouflage.

Weaned pups have to learn to hold their breath, swim and dive before they leave the beach on their first migration. At sea, they will have to learn what to eat and how to catch it. The PBS program Animals With Cameras documented how they practice.

Wildlife cameraman Gordon Buchanan, who narrates with a Scottish brogue, worked with Ano Nuevo researchers Patrick Robinson, director of the Ano Nuevo Reserve, and Roxanne Beltran, assistant professor of ecology & evolutionary biology at UC Santa Cruz, to equip four weaners with cameras to record 16 hours in their lives. Watch the results at the 44-minute mark.

The cameras revealed unexpected behavior. Under water, the weaners interacted with each other more than the scientists’ expected.

“I’m surprised by how active and interactive they are,” Dr. Robinson says, as the seals cavort in their watery home. “They’re completely solitary at sea,” says Dr. Beltran. “So the fact that these guys are interacting with each other is weird. I wonder if they are just learning from each other.”

The video shows that the weaners hold their breath on land as well as in the water. Eventually, they will hold their breath for 15-20 minutes on each dive to feed. The video records one pup holding his breath for almost 12 minutes.

“It doesn’t look like they are doing much here,” says Dr. Beltran, “but I think what they are actually doing is figuring out how to become breathless divers, so that they can find food on their first trip to sea. Just like we would train for a marathon by doing little runs, they’re doing little breath holds to basically figure out how they can get down to food on breath holds.”

The weaned pups are living on their blubber until they depart on their first migration. That blubber makes them buoyant in the water, though. The pups have to work to dive, and seem to help each other stay down.

The video shows them chasing fish, although they don’t catch and eat any. It also shows them playing with plastic trash and kelp. Play is important to young animals’ development.

“In these seals, it may help build those important diving skills, that later they’ll rely on,” says Buchanan.

Glimpsing the seals’ life underwater is thrilling. I watched it over and over. The entire show includes video from loggerhead turtles, tiger sharks, and gannets.

Buchanan calls the elephant seals “elite ocean divers.” Dr. Robinson observes, as they swim underwater, “They’re more graceful than I thought, based on how they are on land.”

 Read online here. 

 

Monday, January 24, 2022

Pup Season at Piedras Blancas!

 Pups start life at Piedras Blancas

High tides, tsunami threaten newborns

The beach is full of mothers and pups, from skinny newborns to chubby weaners, in January. High tides, including King Tides, the highest of the year, were made worse by waves pushed ahead by a tsunami. Pups face the rigors of ocean life from the moment they are born.


Over 5,000 pups will be born in the rookery, which extends north and south from the Piedras Blancas viewpoint. Daytime births are common. Luck plays a part in being in the right place at the right time. A visitor stopped me on Saturday to ask which seal would have her pup next. My eye wandered across the seals below us, to see a pup emerging from one just below us. I recorded this video.



Mother-pup separation

Pups may get separated from their mothers. The usual noise and confusion of life in the harem, the group of female seals over which an alpha bull presides, is distracting under any circumstances. Other mothers are competitors for space, each willing to fight for her own pup. Bulls charge each other, regardless of the mothers and pups in their path.

Add high tides and the potential for mother and pup getting separated only gets worse.

A pup without a mother may die. Separation is the most usual cause of pup death. However, mother and pup have ways to overcome even this danger.

Pups and mothers bond to each other, but that bond can be disrupted by life on the busy, noisy beach. Some pups don’t survive.

Pups have a distress call that all mothers respond to. Mothers have a pup-attraction call, described as a “warbling, yodel-like vocalization.” Observations at Ano Nuevo have found that about two-thirds of the time, mothers find their pups. In some cases, the pup finds the mother. If the pup calling isn’t hers, the mother may ignore it, attack it, or adopt it.

Mothers nursing other pups

Mothers may tolerate other pups nursing. Northern elephant seals do not have twins, but sometimes a mother allows more than one pup to nurse. While each mother has only enough milk to nurse a single pup to adequate weaning weight, around 80 percent of pups nurse at let occasionally on other mothers.



When a pup dies, its mother may adopt an orphan, or she may share a pup with another mother.

Circle of life

In the circle of life on the beach, their remains are consumed by gulls and, when the beach is less crowded, buzzards. Condors from the San Simeon flock may be attracted to them. The condors have not yet made use of this source of lead-free food, but 2022 may be the year one brings the flock to the beach. Lead contamination from hunters’ ammunition is the most frequent cause of condor death.

Tsunami

The tsunami was triggered by the eruption of a volcano in Tonga, more than 9,000 miles across the Pacific. NOAA’s GOES West satellite recorded the event from space, https://www.nesdis.noaa.gov/news/hunga-tonga-hunga-haapai-erupts-again

Hours later, when the rush of water reached Piedras Blancas beaches, Friends of the Elephant Seal’s webcam captured waves crashing against the bluff that reaches to the sandy beach. https://www.facebook.com/friendsoftheelephantseal Any pups that were on that narrow stretch were washed away. Pups aren’t able to swim to save themselves until they are older.

One got stuck in the rocks above the beach. He (or she), a newborn with umbilical cord still attached, struggled to extricate himself from the rocky niche. His mother hovered nearby, barking encouragement, but he was well and truly stuck.

Docents checked on him throughout the day, and eventually found him back on the beach! He’s the only one who knows how he got there, but he did. To end the episode, he and his mother were reunited.



Pups face danger as soon as they are born. For more than 90 percent of the pups at Piedras Blancas, those mishaps have a happy ending, like this intrepid pup.





Thursday, December 23, 2021

Seal breeding season

December begins the elephant seal breeding season. Adults and pups are active. The first pup was born overnight on December 15-16, in the rain.

Pups are born on the sand

Seeing a pup born is exciting. Watch for females fussing and tossing a lot of sand. They sometimes toss so much, they build a sort of perch for themselves, with deep ditches dug out on both sides.



Ask a Friends of the Elephant Seal guide. They may be able to direct you to a mother ready to have her pup. Look for the crowd. Everyone is eager to see newborn pups.

Pups are often a surprise – just when you’re watching one mother, another down the beach squirts out her pup. That’s wildlife.

Be patient. The seals are on their own timetable. Pregnant females will continue to arrive on the beach through February. Most births happen in January, and are more likely to occur at night.

Pups can be born anywhere on the beach, throughout the rookery, from the lighthouse to Arroyo Laguna.



Pups are all black, about three feet long and weight about 70 pounds when they’re born. They soon plump up on their mothers’ nourishing milk. They’ll nurse for a month. In the last few days of nursing, the mothers mate with one or more males. They wean the pups abruptly when they return to the ocean.

Beachmasters are vigilant

Dominance dictates the social organization on the beach. A beachmaster will defend a harem of 20 or 30 females and their pups. The beachmaster needs to be vigilant, because less dominant bulls will constantly attempt to sneak into the harem of females, or make a direct challenge to him. Subdominant, beta, bulls hang around the edges. The alpha bull tolerates some peripheral bulls, who help maintain the perimeter from other bulls.



Watch seals from a distance

Bulls that lose out find their way to other local beaches, sometimes called bachelor beaches. I don’t agree with calling them “loser beaches.” Only 1 percent of male elephant seal pups survive to prime breeding age of 12 or 13 years. Any seal that shows up is a winner in the survival sweepstakes. 

Hearst Memorial Beach at San Simeon Cove attracts them. Human beach visitors may be surprised by a seal among the driftwood.



FES will post guides there for the duration, through March, to advise visitors as to seals they may encounter.

The seals are not aggressive toward humans, but the bulls that come to San Simeon are tired and may be injured from losing their battles with other bulls. They may challenge other bulls to fight on the beach. Human visitors stay safe by giving the seals a wide berth. NOAA Marine LifeViewing Guidelines advise no closer than 50 yards, half a football field. Keep the dog leashed so as not to annoy them. Don’t get between two seals, who may decide to charge each other, or a seal and the water, in case he suddenly decides to go back into the waves.

Informed beach visitors can coexist with the seals. The Piedras Blancas rookery is an example of seals and humans sharing the beach. Stay safe and give the seals time to rest.

 

 

 

Thursday, November 18, 2021

Breeding Season

A single mature bull elephant seal shifted his weight onto the sand at Piedras Blancas in mid-November. He’s the first of a couple hundred who will arrive for the breeding season.

Make a visit to the seals part of your Thanksgiving festivities.

Docents called him Romeo, although he didn’t show much energy. He has been swimming for weeks to return from as far as Alaska. He is taking some well-earned rest before the excitement of the females’ arrival.

Big and blubbery

He’s nice and fat. That’s an advantage to the bulls, who fast while they are on the beach. Recent research has shown that the bulls stop eating on their journey back to the Central Coast, and don’t start eating until they get back to Alaska, in March. They go without food for about five months.

They need a hefty load of blubber to carry them through the challenges of other bulls, to reach the season’s reward, mating with willing females. That’s in the future now. Pregnant females don’t usually arrive until December. After they have their pups, they nurse them for a month or so, coming into heat at the end of nursing and becoming receptive to mating.

Mating involves a lot of barking and tail flipping, but eventually they get the job done. That happens in late January and February. At least some bulls generally stay on the beach until March, when the last female leaves, so it’s a long time between fish dinners.

Young seals prepare to depart

Many juvenile seals remain on the beach through December. They are on the beach for their Fall Haul-Out, a six-week rest. More of those are males than females, because females mature earlier than males. Six-year-old males are still practicing their fighting moves on each other, while females the same age are having their first, second, and even third pups.

A few adult females may be on the beach. They are, for some reason, not pregnant. Whether they mate with younger bulls, or are able to mate under water, isn’t yet known. Over 90 percent of female seals have a pup every year. Those who skip a year present researchers with questions for which they have not yet found answers.

Beach transition

More adult bulls will arrive over the course of November and December. Look for an elephant-like trunk that hangs down onto the sand when the seal is resting, with a notch across it. Pink chest shields are another sign of maturity. Callused pink skin that extends up as far as the eyes when the seal is lying prone is typical of senior bulls.

The first pup of the season is usually born around mid-December. It’s onesy-twosy at first, increasing in frequency as hundreds of females arrive and more pups are born.

Citizen Science opportunity

The Coastal Commission invites all to photograph the extent of King Tides, coming up December 4 and 5. The photos document high water levels, showing how sea level rise will affect the coastline. Find the photo submission form here. Check out the photos taken in previous years of San Luis Obispo beaches. The tide inundated the rookery beaches, chasing seals to the edge of the bluffs.




 

 

 

 

 

 

 

 

 

  

Tuesday, October 26, 2021

Young seals arrive

Young seals arrive for Haul-Out

Construction doesn’t faze them

Seals arrive daily on the beach at Piedras Blancas. They are young, both males and females. It’s the Fall Haul-Out, a rest for the young seals between migrations. They’ll continue arriving through October.

Seals fast for the four to six weeks they are on the beach during this autumn retreat. They rely on their blubber to meet their nutritional needs. They have the beach and the surf to themselves, before the adult bulls begin arriving around Thanksgiving for the breeding season. Some may stay on the beach into December.

Heavy equipment

This year, they are accompanied by construction crews. The culvert under the north boardwalk collapsed last January, during the big atmospheric river storm. State parks workers are replacing it. Seals remain nearby, ignoring the workers, who have fenced off their work area.

They will turn to the south boardwalk to replace a culvert after the north boardwalk is reopened. Part of the north boardwalk is open, from the north parking lot. That parking lot also leads to the Boucher Trail, two miles to the Piedras Blancas Light Station. Several points along that trail overlook elephant seal beaches.


The light station is open for tours by reservation only on Tuesdays, Thursday and Saturdays. Book ahead through recreation.gov.

Boisterous boys

The young males are willing to spar with each other, on the sand and in the water. It’s the nature of young guys to roughhouse. Some nose around young females, but they aren’t willing to mate. The ones on the beach are too young, and they have an estrus breeding cycle. Like dogs, they only mate when they are ready.



The seals take a rest between their two annual migrations. The young seals will leave the beach as adult bulls arrive in late November, migrating north and west until time to return to the beach to molt their skin in May. They left the beach in June, returning now. In between, they are diving and feeding, diving and feeding.

Males and females have different feeding strategies. Males migrate north along the coastline, diving to feed at the bottom along the continental shelf. Females migrate to the open ocean, feeding on prey they encounter there.

Males eat bottom-dwelling fish such as dogfish and hagfish, not targets for human tables. Females eat small fish in the mesopelagic layer. They don’t compete with fishermen, so elephant seals aren’t in conflict with them they way sea lions are.

Adult females

Occasionally a mature female, not pregnant, comes on to the beach during Fall Haul-Out. Nearly all mature female seals are pregnant every year, but some skip a year. Exactly why they aren’t pregnant is a subject of active research at Ano Nuevo Reserve and Sonoma State University. Tracking individual seals and understanding what’s going on is difficult, but researchers are making progress.

We had our first adult female satellite tag recovery procedure last week,” Patrick Robinson, director of the Ano Nuevo Reserve said in an email. “She was not pregnant, but otherwise seemed healthy.  We're still learning about these seals that skip breeding!”