For two years, the head of a rarely seen Antarctic whale has been buried in a soil yard in the San Pasqual Valley near Escondido.
Last week, we finally dug it up.
The specimen belonged to a female southern bottlenose whale (Hyperoodon planifrons), a relatively understudied species of beaked whale that lives in the Southern Ocean around the Antarctic.
So how did The Nat get a whale head from Antarctica? And why did we bury it?
It all began during a NOAA Fisheries expedition to Antarctica in 2020. Douglas Krause, a biologist with NOAA, found the bottlenose whale (not to be confused with the bottlenose dolphin) washed up dead on a beach. A lot of information can be gleaned from such findings, so Krause, who is based at the Southwest Fisheries Science Center in La Jolla, called up our Curator of Paleontology, Tom Deméré, with an offer he couldn’t refuse.
"My first thought was, 'A beaked whale? Yes!'” Deméré recalls. After all, his research specialty is whales and other marine mammals.
“This species has a remarkable body shape, I was excited for what the skull could tell us about beaked whale anatomy,” he says.
When the head arrived to San Diego, it was a bit of a mess. The body wasn’t fresh when Krause found it, and things got pretty smelly during the long voyage back from Antarctica.
“It was partially decomposed when it arrived,” says Scott Tremor, the museum’s mammalogist and team leader for last week’s dig. “It was... pretty bad, but that is often how we receive whale carcasses.”
He and Deméré made sure the whale head was promptly buried.
Temporarily burying bones underground is an important step in the process of adding new bones to our research collection. By allowing nature’s decomposers to do what they do best, we end up with clean, undamaged bones. Tremor says we rely on the dermestid beetles, ants, potato bugs, earthworms, and roaches that live in our local soils to get the job done.
X Marks the Spot
When we arrived at the burial site—a soil yard that supplies mulch and compost—Tremor and long-time volunteer, Vryce Hough, gloved up and grabbed shovels to unearth the large skull. As the morning warmed up, so did we. Digging up a whale head is no walk in the park.
Two hours of sweaty shoveling passed, but there was still no sign of our buried treasure.
We knew we were close, but the stake marking the exact location was broken when we arrived. Hough suggested we call up Deméré for photos from the burial day in 2020 —just in case we were way off. The photos were quickly beamed to Tremor's phone and, with our new intel and a little eyeballing, we concluded we were digging just a few feet off the mark. With tired backs and arms, we thanked Hough for insisting we ask for directions.
Not long after our reroute, Tremor’s shovel thudded into the skull's protective crate, and he let out a relieved cheer. The hardest part was over. After 40 more minutes of shoveling and prying, Tremor finally loosened the crate from the soil, growling for extra strength as he strained against its weight.
The skull was long, about four feet, and surprisingly stink-free. Patches of white mold and dark mud-coated its surface. A few bits of dry flesh clung to the cranial crannies, but the skull was much cleaner now that the decomposers had done their duty. Tremor and Hough carried the 80-pound specimen, still wrapped in chicken wire, to a large tub in the back of the pick-up truck.
Another Data Point for the Books
For the next three months, the skull will soak in that tub with water. Bacteria on its surface will flourish and finish breaking down the remaining soft tissue—a process called maceration. A three-week ammonia bath will follow, then a rinse, and a week in the freezer. By then, the specimen will be cleaned, brightened, disinfected, and ready to serve as part of our research collection.
“The skull isn’t in perfect shape, but it’s rare to find such a specimen,” says Deméré. “Anatomical clues preserved in this specimen have the potential to help us better understand the evolutionary history of beaked whales, and of toothed whales in general.”
So little is known about the various beaked whales of the world, they are practically a new field of study. Their deep-diving, offshore lifestyle makes them difficult to observe, and even more tough to study closely, adds Tremor. While The Nat’s collections are mostly focused on the region of southern California and the Baja California Peninsula, Tremor says that “any type of data on beaked whales is so valuable—we couldn’t let this specimen go to waste.”
Researchers studying modern whales might use the skull for comparative anatomy studies, while paleontologists like Deméré could use it to piece together the evolutionary history of whales to help describe extinct species.
“Undoubtedly, somebody will use it,” says Tremor.
After two years of patient waiting and a tough day of shoveling in the sun, that’s exactly what we like to hear.
This Wild Life showcases ongoing fieldwork at The Nat and the people behind it. Join our researchers and partners as they slog through frog ponds, dig up fossils, and track down lost species—making conservation possible with each data point and discovery. From southern California to the tip of the Baja California Peninsula, our scientists are quite literally the boots on the ground, working to preserve this amazing place we call home.
Mammalogist Scott Tremor and volunteer Vryce Hough dig up a crate containing a southern bottlenose whale skull.
The skull was about four feet long and around 80 pounds. It was wrapped in chicken wire to protect it from shovels during the unearthing process.
The skull still had lots of flesh and tissue when it was first buried. After two years underground, most of that had been eaten away by decomposers.
Wrapped in chicken wire for protection, the skull will soak in water for three months to break down any remaining tissue. Then it will be disinfected and added to our research collection.
Posted by Cypress Hansen, Science Communications Manager on January 24, 2022
Subscribe to our blog. Receive an email once a week that recaps the latest blog posts about our research, exhibitions, cool science news, and more