Considerations

• Whales typically give birth to one calf at a time, although twin fetuses can occur on rare occasions. Mature females of most species, including humpback, beluga and blue whales, usually reproduce every two to three years. The average time between gestation periods for sperm whales is three to four years.
  
  

Size

• Newborn beluga whale calves typically weigh about 175 lbs. A right whale calf's birthweight generally is about 500 lbs. Gray whales weigh 1,100 to 1,500 lbs. at birth. Newborn humpback and sperm whale calves usually weigh around 2,000 lbs. Blue whale calves weigh around 5,500 lbs. at birth.
  
  

Diet

• Whale calves gain the fat they need for healthy growth from their mother's milk. Blue whales and gray whales typically wean their young around seven months after birth. Humpback and right whale calves usually stop nursing by the end of their first year. Beluga whales begin weaning when their calves between one and two years old. Sperm whale calves nurse until their second year.
  
  

Misconception

• Baby killer whales are also called calves, but this species actually belongs to the dolphin family.