Gray Whale Calves
Gray whales reach sexual maturity between 5 and 11 years of age (average eight years), or when they reach between 36-39 feet in length. Breeding can occur from December to April, although it is sometimes seen on the southward migration, most mating behavior is observed in Baja.
Gray whales are solitary in nature; they come together during the mating season but do not form family units. Calves stay with their mother until they are weaned, usually by October. A single calf is born in late December to early February after a gestation period of about 12 months. Most females bear a calf once every two years; a newborn calf is about 15 feet long and weighs about one ton. Calves are nursed for six to eight months on fat rich milk and grow very rapidly during this time. The mother and calf will stay in the Baja area for up to two months while the calf builds up stamina and a layer of blubber for insulation for their northern migration.
During migration and while in calving areas, gray whales eat very little, although they occasionally will eat shrimp like mysids or small fish at the surface. The blubber they add during the summer feedings here off Depoe Bay must provide them with enough energy for the remainder of the year, many whales may go without food for 3, 4 or even 5 months.
During feeding, the gray whale prefers using its right side to scour the bottom and find its food. To feed they gulp mouthfuls of mud from the bottom, then use their baleen as a filter to drain out the unwanted material. This leaves the amphipods stuck to the baleen inside their mouths, and then they use their tongues to loosen the amphipods from the baleen, and swallow.
The gray whale has two blowholes and between 6 and 12 dorsal nodules (knuckles) on its back, they have no back fin. A gray whale spout or blow can reach up to 15 feet, and resembles a heart shape when looking from the front or behind. The natural color of the gray whale is dark gray with their skin discolored from barnacle scars.
Whales are mammals, they breath air, have hair (calves have hairs around the front of their heads), are warm blooded, and give birth to live offspring that suckle milk from their mothers. The gray whale is in the sub-order Mysticeti. The Mysticeti whales have baleen instead of teeth, the male gray whale can reach 45 feet, while the females can reach 50 feet and weigh 30 or 35 tons. The largest gray whales have flukes, or tails that can span about ten feet, gray whales can live up to 50 years, some as much as 70 years.
Below are some interesting facts about Gray Whale Calves
Breeding and giving birth are the reason for southern migration.
Born without a blubber layer, babies need warmer waters.
Moms bear calves about every 2-3 years.
Gestation period averages 12 months (Sperm whale 17 months).
Pregnancy is telescopic; babies double their size the last 2 months.
Babies average 15 feet long at birth (Blue whale 26 feet).
Baby whales are born tail first.
Calves weigh about 2,000 pounds at birth (Blue whale 8,000 pounds).
Babies must surface and catch their first breath within 15 seconds.
Within 30 minutes, babies learn to swim.
Babies nurse frequently on rich milk, 50-60 percent butterfat.
Babies don’t suck, the mother pumps milk into its mouth.
Calves put on as much as 9 pounds an hour.
Mothers lose 1/3 of their weight while nursing.