Traveling with an elephant seal bull

 J912’s tracking device reveals his journey

An adult male elephant seal, marked J912, with a tracking device on his head and an antenna on his back, hauled out February 5 at Piedras Blancas.

J912 ar Piedras Blancas. David Lawrence. 

Friends of the Elephant Seal docent Barrett Stuart was the first to notice that the seal, among many other males on the beach, had a device on his head. In February, breeding season, male seals are on the beach, moving around, seeking advantage with females and threatening each other.  He reported the sighting. FES docents Rian Dom and Dave Lawrence decided to revise their plans for the following day and go look for him.

 “Rian and I were going to tag hunt at VP2, but she suggested we start at VP3 to try to photo this seal,” Lawrence said.  “Rian is responsible for getting me there that following morning. I’m glad we did!”

VP2 is the elephant seal site south of the main viewpoint. “Tag hunting” is looking for seals with flipper tags, to photograph and report to researchers. Resighting tagged seals is important, to document where seals go and when.

Elephant seal J912’s tracking device, glued to mesh that is glued to the seal’s head. Dave Lawrence

Tracking male seals

It’s unusual, and exciting, to see any seal with a tracking device at the viewpoint. It’s always a female. Males are hardly ever tracked.

They, like much wildlife, migrate across international boundaries, making protection complicated. Hoary bats have flown from California to Hawaii. In January, a waved albatross, a critically endangered species from the Galapagos Islands and South America, was seen off Cambria’s coast. The bird had traveled about 3,300 miles from its typical range, making it an avian “vagrant,” the term used for birds outside their usual range.

Wide-ranging wildlife requires a global perspective. In J912’s case, it led to international cooperation to test a tracking device.

Dan Costa, Distinguished Professor of Ecology and Evolutionary Biology at UCSC, and head of the Costa Lab, said “J912 is a male that we tagged at Ano Nuevo last summer-fall after he molted. He is carrying two tags. One of the tags is a device we were testing from King Abdul University of Science and Technology, or KAUST. KAUST is in Jeddah, Saudi Arabia, and has an excellent technology development team. The device had GPS tracking capability and recorded dive behavior, and it used the Iridium Satellite system to transmit data. The other tag is one of our more standard tags built by Wildlife Computers in Redmond, Washington. It recorded diving behavior and animal position; position data were transmitted via the ARGOS satellite system.”

The KAUST tag has a much higher data bandwidth than the standard Argos tags, but is more challenging to establish communications with, especially on diving animals. It transmits GPS locations and has an accelerometer for measuring fine-scale head movement. Those head movements can be interpreted as feeding, when the seal catches prey.

The standard tag collects basic oceanographic data, depth, and temperature, the standard set of measurements for understanding the ocean environment.

“The rationale for the study is to learn more about male elephant seals.,” Dr. Costa said. “We have over 1000 records from individual female elephant seals, but only a few tracks of males (fewer than 50). Males are less reliable than females; that is, they aren’t as likely to return to Año Nuevo, as this individual shows, so there is a greater chance of not recovering the tag and thus not retrieving as much data.”

During the summer, J912 was on the beach to molt his skin. The device was attached after he had molted, to the new skin that would last for a year. He then left to go feed along the continental shelf, gaining blubber to sustain him though the breeding season.

 

In J912’s case, the tracking record shows that he left Año Nuevo on August 30 and arrived in the Aleutian Island foraging site, 2,573 miles away, on October 11, a 42-day migration, averaging 61 miles/day.

At the urge of some unknown signal, after feeding for two months, on December 4 he turned around to return to California from the Aleutians. He arrived on land near Point Buchon, 2,718 miles, on January 17, a 51-day migration, averaging 53 miles per day.

 

In both directions, he travelled in more or less a straight line. He stopped in places, perhaps to eat along the way, but his main goals were the rich foraging grounds in the Aleutians and then to return to California.

 

J912’s tracking records show that he had been around Piedras Blancas for a few weeks, before hauling out on the beach at Piedras Blancas February 5. He visited at least four birthing beaches in the rookery, but it isn’t clear whether he stayed to breed.

He was seen at Año Nuevo a few days earlier, but he was in the water then, and the team couldn’t get to him. “Apparently he stayed in the water and swam south as fast as he could!” FES member Kathy Curtis posted on GroupMe.

I didn’t see J912 while he was at Piedras Blancas. He stayed only two days, then moved on north to the Lighthouse Beach on February 8. He may find a breeding beach where he stays for a while, or move on. The device will record where he goes, and for how long.

The team may leave the device on him until he returns to Año Nuevo to molt, in July. The data from that, and the other four seals’ devices, will add to the understanding of these seals’ lives.

“Our goal is to better understand large male foraging behavior and ecology, energy gain rates, and diving physiology,” another member of J912’s research team said. “The other four males all returned to Año and we were able to recover all of their tags over the last month, which is really exciting.”

The complex tracking equipment on elephant seal JP12’s head allows researchers to collect data on the ocean environment as well as the seal’s dives and migration. Dave Lawrence

Webinar on elephant seals

Dr. Roxanne Beltran and research technician Conner Hale of the Beltran Lab at UC Santa Cruz will discuss how tracking individual variations can contribute to understanding the species in a free webinar "Unraveling individual and environmental drivers of variation among elephant seals," Tuesday, February 24, 7 pm. Register here.

American Cetacean Society - San Francisco Bay Chapter — Dr. Roxanne Beltran, "Unraveling individual and environmental drivers of variation among elephant seals"

Christine Heinrichs is the Monterey Bay National Marine Sanctuary Advisory Council SLO At-Large member. Her elephant seal column won first place from the National Society of Newspaper Columnists in 2024. Follow her on Facebook, Bluesky, LinkedIn, and Substack.