Mating and Reproduction in Dolphins

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The vast dolphin realm (family Delphinidae) consists of 36 distinct species from 17 genera, spotted in oceans all around the planet. Bottlenose dolphins, for example, are part of the genus Tursiops. These aquatic mammals -- and toothed whales -- often reproduce at all points in the year.

Breeding Season

Many types of animals have strict annual breeding seasons, but that isn't so for dolphins. While they often can reproduce at any time, dolphins in certain geographic locations partake in heightened mating activities during both the spring and autumn seasons, however. Female dolphins are known as cows, while the males are known as bulls.

Speedy Mating Activities

When male dolphins woo females, they frequently do so by repeatedly nudging them with their heads. Vocalizations and intricate swimming styles also are often employed as wooing activities. Male dolphins typically initiate mating by going right up to the females, either to their stomach regions or flanks. If a female is indeed open to mating, she'll allow him to proceed. The whole process is usually extremely speedy. It can last for as long as 60 seconds, but is often markedly shorter. When dolphins mate, their stomachs are in direct contact. They generally don't cease motion for mating purposes. Breathing sometimes forces dolphins to disrupt copulation. Once male and female dolphins are through mating, they part ways.

Pregnancy in Dolphins

When female dolphins are expectant, their pregnancies are the same length or longer than those of human beings. Gestational lengths for dolphins across the board are typically between 9 and 17 months. The species frequently differ in typical gestation length. When dolphin mothers give birth, they bear single babies. Twins are possible but are extremely uncommon. Once mother-to-be dolphins sense that they're on the verge of parturition, they isolate themselves from the rest of the members of their social groups. When they do this, they frequently move toward the water's surface.

Dolphin Youngsters

Dolphin youngsters are referred to as calves. They start their lives underwater, emerging from their mothers' bodies with their tails leading the way. At birth, their mothers are generally twice as long as they are. The mothers are usually roughly six times heavier than they are, too. Newborn calves, with the assistance of their attentive mothers, typically go to the top of the water rapidly to take in air. Nursing in young dolphins generally takes anywhere between 11 and 48 months. The juveniles don't leave their mothers as soon as they're weaned, however. Dolphin youngsters often live with their moms until they're 8 years in age, though some depart as early as age 3.

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