On January 3, 2022, birdwatcher Clare Jacobs was delighted to spot a rare white-tailed eagle, or Haliaeetus albicilla, in a nature reserve on the Isle of Wight in southern England. These birds, also called white-tailed sea eagles or ernes, disappeared from the region about 250 years ago, but since 2019, more than two dozen birds have been released on the island.
Ms. Jacobs was aiming her camera at the eagle when she noticed something moving in the water below: a gray seal. A large mammal jumped out of the waves and opened its mouth. “I jumped,” Ms. Jacobs said.
The seal then spat a stream of water at the predator. Although Mrs. Jacobs didn’t immediately notice it, it was very unusual. Spitting seals have never been seen before, and reports of interactions between these two apex predators are virtually non-existent.
Ms Jacobs’ photos were sent to her daughter Megan Jacobs, who studies fossils as a PhD student at the University of Portsmouth, and David Martill, a lecturer at the school. Together they published an observation published last month in the Isle of Wight Natural History and Archaeological Society journal.
Both animals feed on fish, although the eagles also prey on waterfowl and carrion, and the study authors concluded that the seal most likely spat on the eagle to scare off a potential competitor. It looked like the seal told her to “fuck off,” Megan Jacobs said.
Sean Twiss, a professor at the University of Durham who has spent 30 years studying gray seals, has never seen one spitting. He thinks it’s possible the seal was intended to scare away the eagle or was just for fun. Seals often feed at depths and don’t usually feed in bodies of water as shallow as this harbor, he said, so he wasn’t sure what the motivation for the water spurt was.
The discovery makes gray seals one of the few species that spit. The most famous representatives of this coterie are cobras, which can shoot venom from their fangs into the eyes of potential predators with impressive accuracy. He has the ability evolved three times among cobra lineages, says Maarten Jalink, a researcher at the University Medical Center Utrecht in the Netherlands, who studied the phenomenon.
Perhaps the most impressive spitters are archers, he said Stefan Schuster, who studies fish at the University of Bayreuth in Germany. These tiny creatures, which live in mangrove swamps in Asia and the western Pacific, knock insects and arthropods off leaves with jets of water they produce by pressing their tongues to the top of their snouts and squeezing violently. They then quickly eat the fallen prey. This spitting ability requires excellent body stabilization, which can be achieved by activating the fins, Dr. Schuster said.
It also requires incredible vision. It is explained that the upper halves of archers’ eyes are sensitive to the colors above the water, and the lower halves to the colors of submarines. Cait Newport, researcher at the University of Oxford. “Their brains can explain the breakdown caused by being underwater and spitting on objects above the water,” she added. Other fish, such as the Picasso triggerfish, spit on it in aquariums and also use this behavior to find food under sediment and displace things underwater.
Some spiders spit tooselling balls of sticky web to subdue prey from a distance.
Many mammals, such as camels, alpacas and their relatives, are known to expectorate. Such emissions, which include saliva and often stomach contents, arise as a defense mechanism against perceived threats. But spitting can also be a more thoughtful way of moving water from one place to another. In one study published in 2020for example, Bornean orangutans obtained food from an empty tube by spitting water into it. Some monkeys are also known throw seeds over considerable distances from the mouth while eating, probably to feed more efficiently.
Dr. Twiss says these kinds of isolated observations often go unpublished – which was almost the case here. That’s a shame, he said, because rare sightings can teach us a lot about the natural world and alert others to new behaviors worth studying.
The sighting is also an indirect result of the expansion of the gray seal’s range after hunting restrictions and the reintroduction of the white-tailed eagle after centuries of absence. More discoveries await us as populations of these and other species grow and occupy old territories.
