Dolphins can feel the slightest movement of currents around their bodies and being propelled along by a wave is a special thrill for them.
Boats also push pressure waves ahead of them that are like ocean swells. These man-made waves are equally attractive to playing dolphins, which is why they have frolicked ahead of sailors for as long as boats have existed.
Many whale & dolphin species hunt, travel, or socialize together, and dolphins will even annoy whales to make them surge forward and give them a ride.
Dolphin skin is somewhere between nine and twenty times thicker than ours and a new layer grows about every two hours. Surface secretions dissolve the glue of barnacles so that they cannot get a grip.
These are two reasons why most dolphins look so clean and smooth.
Dolphins are highly promiscuous and have a lot of sex for fun and social cohesion. Females will mate with multiple partners, and both genders find many creative ways to masturbate. Captive dolphins sometimes engage in homosexual acts. In the wild, males use copulation to strengthen alliances, but also to assert dominance.
The famous ‘dolphin smile’ is not actually a smile at all. Their head shape is fixed and we are tricked by pareidolia. So, we should not assume that dolphins are always happy.
Dolphin’s teeth are not designed to chew, just to catch and hold fish before the fish is swallowed whole. Open jaws are mostly used underwater to send serious, unfriendly messages to other dolphins, like: “Move away or I’ll bite you!”
The evidence that they carry out their threats is sets of parallel teeth-marks on the skin and fins, called ‘rake marks’. Bottlenose dolphins appear to bicker a lot and can accumulate so many rake-marks that their backs appear white instead of grey.
Dolphins can tolerate and recover from extreme injuries such as shark bites although the exact methods used to achieve this are not known. The healing process is rapid and even very deep wounds do not cause dolphins to haemorrhage to death. Furthermore, even gaping wounds restore in such a way that the animal’s body shape is restored, and infection of such large wounds seems rare.
Dolphins engage in acts of aggression towards each other. The older a male dolphin is, the more likely his body is to be covered with bite scars. Male dolphins can get into disputes over companions and females. Acts of aggression can become so intense that targeted dolphins sometimes go into exile after losing a fight.
Male bottlenose dolphins have been known to engage in infanticide. Dolphins have also been known to kill porpoises for reasons which are not fully understood, as porpoises generally do not share the same diet as dolphins and are therefore not competitors for food supplies.
Various species of dolphin have been known to engage in sexual behaviour up to and including copulation with dolphins of other species. Sexual encounters may be violent, with male dolphins sometimes showing aggressive behaviour towards both females and other males.
Male dolphins may also work together and attempt to herd females in oestrus, keeping the females by their side by means of both physical aggression and intimidation, to increase their chances of reproductive success. Occasionally, dolphins behave sexually towards other animals, including humans.
You can find more interesting facts about dolphins in the book titled “A Book about Dolphins” which I used for this story series.
The authors, David and Lesley, put their hearts and souls into this amazing book. They have worked for more than a decade with wild dolphins in the Port Stephens-Great Lakes Marine Park. Only their love and passion exceeds their knowledge about these majestic animals.