This species is known for its friendly character and curiosity towards
men. Dolphins are predators however, and they show aggressive
behaviours. This includes fights among males for social ranking and
access to females, as well as aggression towards sharks and other
smaller species of dolphins. Male dolphins, during the mating season,
compete very vigorously with each other through showing toughness and
size with a series of acts such as head butting and biting.
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, and yelping.
Copulation is preceded by a lengthy foreplay, then the two animals arrange
belly to belly. The copulation itself lasts only 10 - 30 seconds, but is
repeated numerous times, with several minutes break in between.
The females become sexually mature at age 5 - 13, the males a bit later,
at age 9 - 14. The gestation period is about 12 months, after which the young are born
tail-first in shallow water, sometimes assisted by a "midwife" (which
may be male). A single calf is born every 3 to 6 years that measures at
birth approximately 1m (between 85 and 140cm) and weights about 10 to
30kg. The calf is nursed for 12 to 18 months, however claves start
to eat solid food from the age of 4 months.
Female offspring live closely with their mother for up to 6 years or
even during their entire life. Male offspring however tend to leave
their mother after they are weaned. In general, males are not involved
in the raising of their offspring.