Whale Gestation Period and Chart

Whales are classified as mammals due to their viviparity and because they have milk-producing mammary glands for feeding their babies. As mammals, they are able to support the young for as long as they develop in their womb.

Whales usually gestate one calf at a time. The reproductive rate of these cetaceans is much lower compared to that of other mammals or even other aquatic species, which have much more prolific reproductive patterns determined by shorter gestational periods.

Despite this, the reproductive strategy of whales (known as selection K) is quite efficient for the species. And it is that they only give birth to one calf at a time, but they have a very long life expectancy (some whales live more than 100 years), which is also determined by very little mortality in the first years of life.

Mother Blue Whale and Calf
Mother Blue Whale and Calf

How Long are Whales Pregnant?

The gestation period for whales ranges between 9 and 16 months, Different Whale species have different gestation periods.

Blue Whale Gestation Period

The gestation period for blue whales is 10 – 12 months. Blue Whales have an average gestation period of 11 months.

Killer Whale Gestation Period

The gestation period for killer whales is 15 – 18 months. Killer Whales have an average gestation period of 16.5 months.

SpeciesGestation Period
Dwarf Sperm Whale10 Months
Bowhead Whale10 – 12 Months
Humpback Whale11 Months
Gray Whale12 – 13 Months
Beluga Whale14 – 15 Months