The dusky dolphin lives in temperate oceans around New Zealand, South Africa and South America and is known for its acrobatic displays. They live in groups of up to 300 in coastal waters but stay close to the shore to stay safe during the night.
Dusky dolphins grow to a maximum length of two metres (six feet), and when the calves are born at a size of one metre (three feet) they are already half the size of their parents. Within 18 months calves are weaned and by the age of 7 to 8 they are sexually mature. Breeding season begins in early summer, and this is when dusky dolphins begin to perform acrobatic leaps to impress females.
The interesting thing is that dusky dolphins leap differently according to the time of year and the presence of calves. When newborns are around in late summer adults only perform ‘clean’ leaps where the dolphin enters the water gracefully head-first, whereas when groups get bigger during the winter they have a good splash around and perform noisy body slams. This is thought to be a long-range signal to distant group members, but is likely to disturb young calves.
Image from www.flickr.com/photos/noaaphotolib