Along with the great apes, the dolphin has gained a reputation as being a very intelligent, friendly and emotional animal. I included it here, although it is hardly a mainland mammal, largely so I can use the picture below!
Dolphins are aquatic mammals. The most common dolphin is the Bottlenose Dolphin (as in the photo). These can be seen off much of the coast of France, and indeed in all oceans excluding the Arctic and Antarctic.
Bottlenose Dolphins are grey, varying from dark grey at the top near the dorsal fin to very light grey and almost white at the underside. This makes them harder to see both from above and below when swimming. The elongated upper and lower jaws give the animals their name of bottlenose - the real nose however is the blowhole on top of the head.
Adults range in length from 2 to 4m and in weight from 150 to 650kg but in most parts of the world adult weight range form 200 to 300kg. Males are usually a little longer and much heavier than the female dolphins.
Bottlenose Dolphins typically swim at a speed of 5-11 km per hour, although for short times they can reach peak speeds of 35 km per hour.
Like this picture? See more cute animal photos at France wildlife photo gallery
Every 5 minutes or so dolphins have to rise to the surface to breathe through their blowhole, although usually they breathe more often than this. As a result their sleep is very light. It is possible (not proven however) that one half of a dolphin brain can sleep at a time.
Bottlenose Dolphins normally live in groups of up to 10-12 animals, staying for a long time with the same 'pod' as they are known. The pod will usually contain females and young dolphins, with the males living elsewhere in much smaller groups for much of the time.
Dolphins eat fish as their staple diet, with other sea creatures such as squid and octopus also being eaten occasionally.
Why we all love dolphins
Dolphins do not fear man, and vice versa, and this has played a large part in the affinity that man has for dolphins. Dolphins will happily approach people in the water, or swim alongside boats. More curiously, dolphins have been known to rescue divers from drowning by dragging them back to the surface of the water, much as they do with their own young.