Longest gestation periods in the animal kingdom
The elephant has the longest gestation period at 22 months. This is longer than that of the blue whale, which is one year. Some species of dolphins have a gestation period of 17 months and sperm whales carry their young for up to 19 months. Rhinos have a gestation period of about 450 days. Owing to such long gestation, the population of these species are not quickly replenished.
