Tuesday, January 3, 2017

Sharks!

January 2 was an unusual day at the bluff. I saw several things I've never seen before: a shark-killed carcass, a shark-bitten bull who will survive, a beachmaster bleeding from fighting wounds, a pup washed to sea and swimming for his life, and another pup nursing so much the milk dripped down.

The shark attacks, reported to Brian Hatfield, the USGS wildlife biologist who follows shark activity, follow a report in the newspaper of a 22-foot great white shark that stole a lingcod off a fisherman's line off Montana de Oro, 50 miles south of here.
These remains clearly show the impressions of shark teeth.

This adult bull was recovering from shark bites to his flippers.


Sharks attack from below and behind. Adult bulls are not thought to be their most vulnerable prey. A big bull like this can turn around and bite the attacker. An injured shark could be unable to hunt.

This beachmaster is the first on the beach, presiding over a harem on the south end of the site. The calloused area on the chest, the chest shield, develops as the seal matures, and is a thick skin that takes the worst of most fights. Bulls rip and tear at each other with their teeth. This one's bloody injuries invite the speculation: What does the loser look like?

One pup got washed out to sea. Apparently, pups can swim when they are born. He was only a few days old, yet swam back and forth in the surf. Unfortunately, he didn't know enough to come back to the beach. It was raining hard and I didn't wait to find out.

On the beach, this pup was enjoying a good feed. a gull came over to steal milk.
It's a mixed bag during the breeding season. Heavy rains are forecast later this week. We'll see how that affects the seals.

Tuesday, December 27, 2016

King Tides

California had King Tides in December, and more will happen January 10, 11 and 12. I took photos of some local places during the December tides, comparing high and low tides:


Leffingwell Landing. I had to back up when I came returned for the low tide picture, in order to show the tide line., so the photos are not from exactly the same vantage point.


San Simeon Cove, looking north from the pier.

San Simeon Cove, looking south from the pier.

Piedras Blancas elephant seal rookery.

I'll repeat this on the tides in January.

Wednesday, December 21, 2016

Green Tie is back!

Green Tie, an elephant seal bull who was initially rescued from plastic entangled around his neck in 2011 is back on the north beach at Piedras Blancas. He's easily recognizable because of the unique double scar from the green plastic that cut deep into his flesh.
Rescuers gave him the name after freeing him from the plastic. He got attention in 2012 and 2013, when his scar looked as if it might still have foreign material in it. He was sedated so that the veterinarian could examine him. She determined that the skin was inflamed, a skin fold dermatitis, that posed no threat to him.

In 2011, his weight was estimated at 700 pounds, making him one of the largest seals ever rescued. In 2013, rescuers estimated him at 1,100 pounds. He's really big now, certainly well over a ton.
When he raises up, the scars show clearly that he is no longer entangled. Those scars tell a terrible story, though.

I use him as a teaching animal, explaining to visitors how this happened and what it took to save his life. He's my ambassador for clean oceans.

Being able to recognize an individual makes him feel special. And, in his own way, cute. I wonder whether he will rule a harem this year and mate.

Thursday, May 5, 2016

Tagging seals for research


There’s always something different to see at the elephant seal viewpoint. Beachwalker Elizabeth Bettenhausen spotted this marked seal at Arroyo Laguna beach in April. Her sighting became part of Patrick Robinson’s research.
Dr. Robinson, UC Año Nuevo Island Reserve Director and UC Santa Cruz lecturer, has marked hundreds of flipper-tagged animals each year. The markings make it easier to identify them from a distance, without disturbing them. Or, incidentally, putting the observer at any risk. Watch how Dr. Robinson marks the seals in this video.

“We marked this seal up at Ano Nuevo a few months ago and it appears to have returned home,” he said. “I'll incorporate this sighting in our database.  Many thanks!”

His research is discovering where seals go, and identifying which seals are on local beaches. This seal is in a general demographic study.

The dyed markings are temporary. They will peel off with her skin when she molts, which is happening in April and May.

Elephant seals molt their skin annually in the spring. All other seals molt, but most do so gradually, so it isn’t as noticeable. Molting seals show pearl gray new skin underneath the tattered old brown skin, peeling back.

The new skin is already formed beneath the old skin. Blood gradually stops flowing to the old skin, and it peels off in pieces. Friends of the Elephant Seals docents have samples of it to show visitors. Visitors are welcome to touch it, feel its bristly hairs. Some visitors are reluctant, but most are willing.

Some of the seals have a color-coded tag on their hind flippers that indicates where they were born. About three quarters of the seals return to their birth beach. About ten percent of Piedras Blancas seal pups get a white tag. All colors of tags show up here. The tags are small, only an inch and a half long, and can’t be seen when the flippers are folded, as they usually are when the seals are at rest. Look for a seal stretching its flippers to see a white, red (San Nicolas Island,) yellow (San Miguel Island), pink (Farallones Islands and Point Reyes), purple (Gorda) or green (Ano Nuevo) tag.
This seal got two white tags.
This yellow tag indicates the seal was born on San Miguel Island.
 
Markings and tags allow researchers to glean information about where the seals go and what they are doing there. Citizen scientists who see markings help by reporting sightings.

Elephant seals are deep divers, spending their days at 500 to 2,000 feet down in the ocean. That makes them difficult for fragile humans to follow. We’d be crushed at the pressure, more than 60 times the atmosphere on the surface. Humans experience serious effects at 100 feet, and even professional free divers don’t go past 400 feet. Digital tracking equipment opens opportunities that would otherwise be beyond human observation.

Tell a blue-jacketed docent if you observe unusual markings. Be part of the adventure of elephant seals.
Published in The Cambrian.

 

Monday, March 14, 2016

Weaners take over the beach

In March, the uproar of breeding season is past. Weaners have the run of the beach.
The rain we had generated large amounts of runoff from the ranchlands across the highway. But the weaners are grown up enough now that they aren't in any danger. They used the stream for breath-holding practice.
One had trouble climbing out. as he lurched up the sandy side, it collapsed under him.

 He finally moved to a section where the bank was shorter and was able to climb out. Another weaner took an interest.

 
 

Thursday, February 25, 2016

Peace on the beach

Breeding season is winding down, and the beach is much calmer. Dominant males are still being challenged by other males, but the level of energy is lower. They care, but not as much. Everyone is tired.

Weaner pups are molting their birth black coats. It's more like shedding than the actual skin peeling off that comes later in life.
Males mate as they can with females before they leave on the next stage of their migration.
We've had some high tides and big waves, but the weaners are able to navigate the beach away from high water. Soon the adults will be gone and they will have the beach to themselves.

Wednesday, February 3, 2016

Pups at high tide


Plenty of pups squirm on the beach in January, under the watchful eyes of their mothers. The bulls are less concerned, with their attention focused on mating. This year’s high tides and storms have added to the chaos.
Elephant seal pups can’t swim when they are born. That inability must be a holdover from their evolutionary past, when their ancestors were land mammals. As helpless pups, they are at risk of drowning as waves inundate the beach.

At Piedras Blancas this year, there’s almost no beach above high tide line at the north end of the boardwalk. Seals have crowded up next to the fence to stay above the water. Visitors are thrilled to get such a close look. But bulls battling each other and mothers shoving each other for space can separate mothers and pups, and make it difficult for them to reconnect. One docent counted 21 pups in a group that included only 14 possible mothers last week.
In the limited space left to mothers and pups, they crowded together to stay out of the waves. Look for mothers surrounded by three or four pups. Elephant seals give birth only to a single pup. Twins are unknown. Mothers don’t eat for that month while they are nursing the pup. They create milk by metabolizing their blubber. Each seal is plump enough to feed one pup, but not more. Any extra drains her resources further. 

Losing track of each other is serious, the single most common cause of pup death. Some mothers will nurse other pups, but other chase them away. Inexperienced mothers may learn from mothering other pups, but the milk they drink may deprive her own pup of the food he needs to grow. Some mothers are willing to foster a pup for a few days. Mothers whose pups die may adopt a stray, or even attempt to steal a pup from another mother.

Last week, one mother searched for her pup as the tide receded. Mothers and pups identify each other by sound and scent. She sniffed around, and barked occasionally. Pups around her slept on, but she likely reconnected with her little one before the tide returned. About 95 percent of the pups at Piedras Blancas survive to weaning.

The south end of the beach has more dry land for pups, so there’s less confusion there. Watch for the dominant bulls, beachmasters, to defend their harems. That big seal with a long nose may appear to be asleep, but he knows is some younger interloper tries to approach a female. He’ll warn the intruder off with a look and a bellow. If that’s doesn’t work, he’ll rise up and wave his nose. He’ll charge and attack the younger bull, who may escape or turn to fight.

Read the column in The Cambrian.