Dolphins are often regarded as one of Earth's most intelligent species, though it is hard to say just how intelligent dolphins are as straightforward comparisons of species' relative intelligence are complicated by differences in sensory apparatus, response modes, and nature of cognition. Furthermore, the difficulty and expense of doing experimental work with large aquatics means that some tests that could meaningfully be done still have not been carried out, or have been carried out with inadequate sample size and methodology. See the "cetacean intelligence" article for more details.
Dolphins often leap above the water surface, sometimes performing acrobatic figures (e.g. the spinner dolphin). Scientists are not quite certain about the purpose of this behavior, but it may be to locate schools of fish by looking at above-water signs, like feeding birds. They could also be communicating to other dolphins to join a hunt, attempting to dislodge parasites, or simply doing it for fun. Play is a very important part of dolphins' lives, and they can often be observed playing with seaweed or play-fighting with other dolphins. They even harass other locals, like seabirds and turtles. Dolphins also seem to enjoy riding waves and frequently 'surf' coastal swells and the bow waves of boats.
They are also willing to occasionally approach humans and playfully interact with them in the water. In return, some human cultures such as the Ancient Greeks treated them with welcome; a ship spotting dolphins riding in their wake was considered a good omen for a smooth voyage. There are many stories of dolphins protecting shipwrecked sailors against sharks by swimming circles around them.
Comments