The females become sexually mature at 5 – 13 years old, the males at age 9 – 14 years old. It change with the species.
Courtship behaviour of the male includes clinging along to the female, posing for the female and trying to seduce her by stroking, rubbing, nuzzling, mouthing, jaw clapping (cf picture), and yelping.
Dolphin reproduction start with the copulation of a couple of dolphins. The copulation lasts only 10 – 30 seconds, but is repeated numerous times, with several minutes break in between and occurs belly to belly initiating the gestation. The gestation period is 12 months, after which the young will born tail-first in shallow water. A single calf is born every 3 to 6 years. That measures at birth approximately 1m and weight about 10 to 30kg. The calf is nursed for 12 to 18 months, however baby dolphin start to eat solid food from the age of 4 months.