Beachmasters dominate their domain

 Get a close-up look at the big bulls

August is a good time to look closely at elephant seal bulls at Piedras Blancas. They have conveniently placed themselves near the visitor entrance at the north end of the parking lot.

A few juveniles are early arrivals for the Fall Haul-Out, their annual rest before the adults take over the beach for winter breeding season.

The smallest are the Young of the Year, last winter’s pups. Those who have survived return to the beach from their first migration. Only about half survive, so every young seal who is on the beach has already passed a major hurdle on the way to adulthood. They still look perfect, their skin smooth and unscarred.

Fine points of dominance

Only males grow the trunk-like nose, technically proboscis. It starts growing when the seal is about five years old, and continues throughout its life. Nose size is a relative indicator of age.

The other visible indicator is the chest shield, the pink skin on that blubbery chest. It starts as a roughness or puckering of the skin and grows along with the nose. Fully mature bulls have a chest shield that is level with their eyes. Now, that’s a beachmaster!

The adult bulls will leave the beach soon, to continue feeding and gaining blubber. They need to be at their physical peak for the breeding season. They will return in November and December for the duration, about 100 days.

Countershading

Several visitors this week asked about the light-colored bellies on seals sleeping on their backs. It’s a common ocean camouflage. Predators swimming below them see the light belly blending with the bright surface above. Those swimming above the seal see the dark back blending into the dark depths.

Poop

Several recent visitors were vitally interested in elephant seal poop. Seals rarely poop on the beach – thank goodness, we wouldn’t be standing mere feet above them if they did! The smell would be overwhelming.

As the seals leave their foraging grounds up north to return to the beach, they eat only prey that happens into their path. They poop out most of what they’ve digested along the way. What’s left is the remains of red blood cells being recycled during that fast. The result is bright orange liquid poop.

It's not an established fact, but I’ve occasionally observed seals poop out an orange cloud just before they surf out onto the sand. Thank you!

Young seals

Some of the small seals are juveniles, two or three years old. Young males and females look very much alike. Around age five, males begin growing that nose, and getting bigger than females.

They are the early arrivals for the Fall Haul-Out, six weeks or so of rest. The young seals migrate along the same routes as their elders, although they don’t go as far as the other adults until their third or fourth migration.

They are diving and feeding almost constantly, more than 20 hours a day.

They arrive and depart individually, so young seals will be on the beach through the end of November, and perhaps beyond.

https://www.sanluisobispo.com/news/local/environment/article264691139.html

Bull molting season

 Fewer but bigger seals on the beach

It’s bull seals’ turn to take over the beach. They are here to rest and shed their skin in July and August, the annual molt.

Summer marks the conclusion of the short post-breeding migration. The seals on the beach are mostly pretty good size, but they will get a lot bigger during the long migration, from August to November.

Catastrophic molt

All elephant seals molt their skin once a year. Female seals and juveniles were on the beach in May and June. They have returned to the ocean, leaving the beach to the bigger males.

This group of elephant seal bulls looks ratty, but they are just molting their skin. Note the crease beginning to develop in the nose of the seal in the center, indicating that he is six to seven years old. (Christine Heinrichs photo)

Last year’s brown and tan skin, actually a layer of keratin, peels off in chunks, taking the hair with it. Beneath it is a pearly gray or silver coat. They look terrible, but it’s normal. Back in the 1960s, before locals recognized the seals, a resident who saw one called the police to report this sickly seal. An officer came out and agreed that it looked bad, and shot it to put it out of its misery. Burney LeBoeuf recounts the incident in his book, Elephant Seals: Pushing the limits on land and at sea.  “Of course, the seal was fine; it was just molting.”

Ask a blue-jacketed Friends of the Elephant Seal docent to see and touch a sample. It’s rough, not soft and silky, like otter or fur seal fur. Elephant seals rely on their blubber for warmth, not their fur.

Seals spend an average of 32 days on the beach to molt. They arrive and leave individually over the summer months. Seals are solitary at sea. Every seal for himself.

Adults and youngsters

The seals currently on the beach are mostly subadults, about six years and older, and fully adult males, eight years and older. The size of the nose is a rough indicator of age. It starts growing when the seal is about five, and continues throughout its life. A few juveniles, and even some of last year’s pups, now called young of the year, find places to rest among their much larger cousins.

Sleeping in the sand

Notice that seals sleeping on their sides breathe only through the nostril that is on the opposite side from the sand. It’s a reflex behavior, shutting the nostril close to the sand to avoid inhaling sand. This ability to close one nostril independent of the other may be related to their adaptation to deep diving under high pressure.

Navigation

Exactly how elephant seals navigate their migration, as far as 5,000 miles, isn’t known. Experiments that took seals about 40 miles from their home rookery showed they found their way back in a couple of days. Tracked during their dives, the researchers found that even as seals drifted downward on their dives, spiraling as many as 20 times, they headed in their original direction when they got back to the surface.

Since they are underwater most of the time, whatever clues beckon them on their way must be ones that they can discern underwater. That could include acoustics (sound), geomagnetism, and visual clues from the shoreline.

I wonder if they look for Davidson Seamount and Morro Rock. What does their underwater world look like to them?  

 

Bulls return

 

Females, young seals gradually leave the beach

An other-worldly moan rises from the beach, warbling on the crisp wind. It’s a female elephant seal at Piedras Blancas. If it weren’t such a bright sunny day, I’d be creeped out.

Female seals usually bark, unlike the belching bellow of the males. But they are capable of variations on their vocal theme. Those yodels must mean something to them, as yet undeciphered by their human observers.

The crowd disperses

Most seals have vacated the south beach, but the seals still crowd the north end of the viewpoint. The adult females and juveniles of both sexes who are concluding their molt take little notice, but adult bulls are arriving, one by one. Soon they will dominate the beach.

It’s the usual summer transition. Time for the juveniles to return to the ocean for a few months. They’ll return in the fall for a few weeks rest, then spend the winter at sea, leaving the beach to the breeding seals.

Pregnant females

The females came into heat as they stopped nursing last season’s pups. They mated and the next pup got started, but in a process called delayed implantation, the embryo stopped developing after a few cell divisions. The females returned to the ocean for their annual short migration, from February or so to May.

That gives them a chance to regain some of the blubber they lost while nursing their pups. They stay on the beach with their pups during the birth and breeding season, not eating. They lose about a third of their body weight.

Adult females leave to spend the next seven months feeding at sea. They are pregnant with the next generation, and will return in winter to give birth.

Return of the bulls

Bulls are returning. It’s their turn to have the beach to themselves in July and August, while they molt their skin. The old brown and tan skin peels off in chunks, revealing the new skin underneath. New hairs are just beginning to grow, making the skin gray. As the hair grows, the color becomes brown.

The upper layer of skin is new, but old scars remain.

These two bulls are companionable on the beach during the summer molt. (Christine Heinrichs photo)

The adult bulls are the ones with the trunk-like nose that gives them their name. The nose, technically proboscis, and the chest shield, begin growing at puberty, when the seal is about five years old. They grow throughout the seal’s life, so chest shield and nose size are relative indicators of age.

Bulls don’t fight much during the summer. They may bellow at each other occasionally, but flipping sand is about the most activity on the beach in June. It’s a good time for summer visitors to observe them at rest.

This senior bull, with a large nose and chest shield, eyes the two younger ones sparring in the surf. (Christine Heinrichs photo)

Elephant Seal Visitor Center

Friends of the Elephant Seal celebrates the grand opening of its new, expanded visitor center in Cavalier Plaza, 250 San Simeon Avenue in San Simeon on July 16. Starting at 11 am, they’ll have a program of research and educational presentations, children’s story time, book signings, a Seal Science exhibit, new exhibits on how blubber keeps seals warm, seal anatomy, diet, and local predators. Guides will be available to answer questions. State Parks staff will lead a guided walk along the Boucher Trail, north of the viewpoint, which overlooks several more elephant seal beaches.

The center is open for visitors daily 10 am-4 pm. https://elephantseal.org/july16/

 

 

Welcome back!

 

Adult females and all juveniles return to the beach

More seals are on the beach in May at the Piedras Blancas elephant seal viewpoint than any other time of the year. Adult females, returned from their short migration, sleep. Juveniles, both male and female, have been out to sea all winter. They now fill out the beach crowd. Young males spar while their elders take advantage of the time to rest and all molt their skin.

Researchers marked M 92 and watched her give birth to her pup. They observed them until the pup was weaned. Then the pup got two white tags, so his appearance can be tracked. (Christine Heinrichs photo) 

Molting

The obvious change the seals undergo is molting their skin. The old brown skin and hair peels off in chunks, exposing new skin and hair underneath. Look for pearly gray seals next to brown and tan seals. Check out the ones with skin curling off around eyes and nose. Old scars also start peeling back the molted skin.

The process carries its own distinctive aroma, from all those mammals shedding skin on the beach. A few of the less thoughtful have orange feces smeared on their back ends.

Good thing the seals don’t defecate on the beach, or the smell would chase visitors off the boardwalk. It’s just a few outliers who add to the smell.

The seals stop foraging for food a day or two before they arrive, and don’t eat anything while they are on the beach. Their digestive and metabolic processes change. My observation is that arriving seals often defecate just before they arrive on the beach, leaving an orange bloom behind them.

Female migration

The females are undergoing changes as the egg that was fertilized back during the breeding season now implants in the uterine wall and begins to develop into an embryo. The process is called delayed implantation. After fertilization, the egg divides a few times and then pauses.

The process gives the mother time to restore her weight so that she is strong enough to carry the pregnancy to term.

Starting now, gestation takes about eight months. The females will leave the beach in a month or so. They will return in January, after their long migration, to have their pups.

Look for marks, other species

With research projects ramping up at Cal Poly and other locations adding marks, marked seals are more commonly seen on the beach. All marks are temporary, since they come off with the molted skin.

Other wildlife share the beach. A Guadalupe fur seal pup and a California sea lion pup hauled out on the beach recently. Every day brings different animals and birds to the viewpoint. The elephant seal viewpoint is easy to access but provides world-class wildlife viewing.

Monterey Bay National Marine Sanctuary is one of 15 that protect seascapes, wildlife and maritime heritage resources. Save Spectacular is the theme of the 50^th anniversary.  (Douglas Croft photo NOAA)

The beach is within Monterey Bay National Marine Sanctuary. To celebrate 50 years of national marine sanctuaries, NOAA has compiled a series of Resource Collections. Peruse the many events, photos, lesson plans, maps, and other educational materials at https://sanctuaries.noaa.gov/50/?utm_medium=email&utm_source=GovDelivery. One covers Ocean Sound and Impact of Noise, https://sanctuaries.noaa.gov/education/teachers/ocean-sound/. The SanctSound Monitoring Project offers a portal that provides downloadable tools for comparing ocean sound, with six tutorials to help use the data.

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.

 

 

 

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.

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.