"Shell-ebrity" Chefs of the Sea.
Indo-Pacific dolphins have once again been spotted off the coast of Australia "shelling." Shelling is a clever hunting trick where a dolphin chases a fish into a big empty seashell. The fish believes it is safe to hide inside the shell, but they are in for a surprise. The dolphin sticks its beak (rostrum) into the shell opening, tilts it upward, & lifts the whole shell out of the water. As the shell rises above the surface, the water drains out & the trapped fish slides out of the shell & into the dolphin's mouth. No hands are needed because their beak acts as a lever, the neck & body as a crane, & gravity & draining water as the "tool" that delivers the fish. Dolphins are among the most intelligent animals on Earth, in the same cognition league as apes, elephants, corvids, & some parrots.
They are even comparable to young children, ages 3-6, in understanding cause-and-effect (If I lift the shell, the fish drains out). Social learning by juniors copying their mothers & their peers. Their memory is sharp & long-term, recognizing individuals & sounds. They problem-solve, for example, in using sponges to protect their nose while hunting. They have fantastic memories, remembering the sounds of humans & other dolphins for more than 20 years. They have the longest social memory ever recorded in a non-human animal. Dolphins don't recognize "faces" the way humans do. Their world is sound-based, but they remember human voices, signature whistles, & individual acoustic patterns for decades. Shelling is comparable to chimpanzees that fish for termites with sticks or corvids that bend wires to form hooks, or elephants that use branches to swat flies, and parrots that solve problems.
Shelling is rare & requires planning (chasing fish into empty shells), manipulation (lifting the shell correctly), understanding cause-and-effect (water drains-fish falls out), teaching (calves learn the same trick by watching their mothers), & is an example of cultural transmission, meaning the behavior spreads socially, not genetically. Because male bottlenose dolphins in the Indo-Pacific have very different priorities than females, all bottlenose dolphins that teach their young shelling tricks are female. Their daily schedule is basically competing with other males, forming alliances, pursuing females, patrolling territories, engaging in social politics, & maintaining dominance relationships. All of this takes time, energy, & attention.
By the way, engaging in social politics is not running for president, forming political parties, or debating policy on CNN; rather, it's relationship management, power negotiation, & strategic alliances—the dolphin version of "who's friends with whom" & who teams up to get access to the girls. Think of it as bromances with rules, friendships with strategy, alliances with benefits, & drama with consequences. Male dolphins spend a huge amount of time maintaining these relationships.
It is females who discover the "trick" & show it to their calves, who then copy their mothers. This behavior becomes matrilineal culture. This is similar to how female elephants teach their young how to migrate, how female chimpanzees teach their young how to crack nuts with rocks, or how female orcas teach their young how to hunt.
