It is difficult to tell the dolphin sexes apart with being able to see their undersides. Males have two slits that look similar to an exclamation point. The longer slit contains the genitals, while the smaller one contains the anus. Two small pores are present on either side of the genital-anal slit. The penis extends quickly from the forward slit when the dolphin has an erection.
A female has a single slit which houses both the genitals and anus. They have a further slit on each side of the genital slit where the mammary glands are located.
Dolphins may mate at any time of the year, and also appear to have sex recreationally with great frequency. Copulation occurs with the two dolphins belly to belly. Dolphins experiment sexually and sometimes display sexual behaviour towards other animals, including humans. Recent studies suggest that dolphins do take pleasure in sex like humans.
The bottlenose dolphin pregnancy lasts about twelve months, and there is usually at least three years between births. Female dolphins often seem to take on the role of “midwife” during a birth have, and others also act as baby-sitters.
Dolphins, like almost all mammals, give birth to live young. Bottlenose dolphins’ newborns are usually about a metre long and born tail first. They will weigh about 11-18 kgs. The mothers nurse them with mammary glands. The young take milk frequently all through the day and night. The rearing of the young is almost exclusively done by females.
Males become sexually mature around eleven years of age, females a little at around nine years of age.
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