California gray whales are the most commonly seen baleen whale in Monterey Bay. Calves are about 17 feet (5.2 m) long at birth and are 20 feet (6.1 m) long by the time they pass Monterey heading north with their mothers in the spring.
Newborn calves are dark, wrinkled and barnacle-free. In the warm calving lagoons in Baja California, a calf remains in close contact with its mother, often swimming onto her tail flukes. Before making the trip north, the baby grows and fattens on 50 gallons (189 l) of milk a day.
Like all species of great whales, the gray whale was in danger of extinction until protected by law in the 1970s. This allowed the population to recover and it was removed from the Endangered Species list in 1994. In the late 1990s, the population was as high as 26,000, but today hovers around 18,000. Scientists believe that changing ocean conditions impact its food sources.
When feeding on the bottom this whale lies on its side and sucks in sand or mud, leaving a large pit. This disturbance of the bottom in feeding areas determines the kinds of animals that live along the bottom.
These whales migrate 10,000 miles each year, from feeding grounds in the Bering Sea to calving lagoons in Baja California and back.