Did you know? The brain of an adult bottlenose dolphin is about 25% heavier than the average human adult’s brain.
At the Institute for Marine Mammal Studies in Mississippi, a dolphin named Kelly caused quite a stir in 2003, when she exhibited a higher level of intelligence than trainers expected. All the dolphins at the institute were trained to hold onto any trash that fell into the water. Then, they could trade the trash for fish, thus helping to keep their pools clean.
Kelly took this task one step further. When people dropped paper into the water, she would hide it under a rock at the bottom of the pool. The next time a trainer passed, she would swim down to the rock and tear off a piece of paper to give to the trainer. After a fish reward, she would go back down, tear off another piece of paper, and turn it in for another fish. She would continue this process, realizing she would get the same reward for a small piece of paper as a large one, and proving that she understood the concept of delayed gratification.
One day, Kelly caught a large sea gull who had flown into the pool area to steal fish. She gave the bird to the trainers and was rewarded with lots of fish. This gave her a new idea. The next time she was fed, instead of eating the last fish, she took it to the bottom of the pool and hid it under the rock where she had been hiding the paper. When no trainers were present, she brought the fish to the surface and used it to lure sea gulls to the pool. Then, she would catch the gulls and trade them in for even more fish. After mastering this lucrative strategy, she taught her calf, who taught other calves, and so gull-baiting became a popular game among the dolphins in Mississippi.
This information was pulled from the writings of zoologist Anuschka de Rohan who produced a Wildlife documentary called, Dolphins – Deep Thinkers? Information was also incorporated into an article in the July, 2003 issue of BBC Wildlife Magazine.