Students Ask and Experts Answer Life Cycle Q. How long does a gray whale live? A. Grays can expect to live about 30 to 50 years. Some may live 60 years. Q. At what age do gray whales mate and breed? A. Gray whales reach sexual maturity somewhere between 5 and 11 years of age, or when they reach 36-39 feet (11-12 m) in length. Q. How long is a gray whale's pregnancy? A. Gestation is 11-12 months. Migration and reproduction are connected; since it's best for the mothers to reach warm waters before giving birth, gestation is carefully timed. Gray whales have a special adaptation called delayed implantation. The embryo does not start developing in the mother's body until a few months AFTER she becomes pregnant. After mating in the lagoons (or during migration), the newly pregnant female returns to the arctic feeding waters on spring's journey north. She feasts for herself and her unborn baby, and migrates south in fall or winter to the nursery lagoons to give birth. By the time she reaches the warm lagoons, the baby has been developing for 11-12 months and is ready for birth. A female usually has one calf every two years. Q. What do newborn calves look like? Photo Keith Jones A. Newborns are dark gray to black, although some may have distinctive white markings. A calf weighs 1,100-1,500 pounds (500-680 kg) and is about 15 feet (4.5 m) long at birth. Some whale watchers fondly call them "pickleheads" because the dimples in their skin resemble the dimples on a pickle! Q. What do baby gray whales eat? A. Whales are mammals, so calves nurse on their mothers' milk. They nurse for round 6 to 8 months. They will drink about 50 gallons of mother's milk each day. Whale milk is rich--about 53% fat. (Human milk is about 2% fat.) Q. Where are the baby grays born? A. Mating and calving both occur mainly in the lagoons of Baja California, Mexico. The shallow, warm, sheltered lagoons are ideal nurseries. However, calving and mating are sometimes seen during the migration, too. Q. What makes the lagoons such good nurseries? A. The shallow lagoons are safe from hungry orcas. The warm water helps the calves stay warm until they gain blubber. The salty water makes the babies more buoyant so it's easier for them to nurse. Q. Why do mothers and calves stay in the shallow lagoons for 2-3 months? A. This time allows the calves to build up a thick layer of blubber. They need blubber for energy to swim during the northward migration. Blubber keeps them warm in the colder waters. Q. Are whales good mothers? A. Yes! Mom-and-calf pairs share a tender bond, in human terms. Mothers are very protective of their calves. They earned the name "Devilfish" from early whalers in the lagoons because of their violence towards whalers who killed their babies. Q. Whales are mammals, so what happens when a baby whale is born underwater? A. A mother supports her calf at the surface for its first few breaths of air. She buoys up the baby with her own back and flukes. Q. When are gray whale calves born? A. Calves are usually born from late December to early February in the warm, shallow lagoons of Baja California, Mexico. More than half of the births occur in Laguna Ojo de Liebre, also called Scammon's Lagoon. Q. How big are baby gray whales when they're born? A. Calves average about 15 feet long at birth and weigh around 1500 pounds. Calves may gain 60 to 70 pounds each day on their mother's fat-rich milk. They reach 18 to 19 feet in length in their first 3 months of life. Q. Can baby whales swim right away? A. Within three hours of birth, a calf can keep itself afloat and swim on a steady course. A calf may rest on its mother's back or fins until it becomes a stronger swimmer. This Season Teachers Kids Orientation Registration Search Copyright 1997-2009 Journey North. All Rights Reserved. Questions or comments? Contact us.