The migration of the California Gray Whale is one of the most amazing animal behaviors on record. Every winter, beginning in mid-October, Gray whales (Eschrichtius robustus) migrate south from the Bering Sea to the warm lagoons of Baja California (6,000 miles). Breeding along the way, they arrive at the lagoons in December and January and it is here that they give birth to their young. When the calves have grown big enough for the trip home the whales start heading north again from February to May.
There are three major breeding grounds in Baja: Laguna Ojo de Liebre (once known as Scammon’s Lagoon, see below), Laguna de San Ignacio and Bahia Magdalena. Laguna Ojo de Liebre is also the home to the Parque Natural de la Ballena Gris, a national park.
Gray whales are baleen whales. This term refers to the bristled plates that hang downward on either side of their upper jaws. These bristles act as a sieve to filter food out of the water. Their upper jaws can expand when taking in large amounts of water and when the water is forced through the bristles, small invertebrates are left behind and eaten. An adult gray whale can eat approximately 2,600 lbs (1,200kg) of these small crustaceans. When migrating and calving however, the grays eat very little.
Gray whales are mottled gray in color. They are covered in barnacles and usually have scrapes and scars from feeding along the bottom and from encounters with their only water-borne enemy, the Killer Whale. Gray whales have no dorsal fin but have a low hump followed by 9-12 knobs. The flippers are large and paddle-shaped and the tail very broad, its width equaling almost 25% of the body length.
Gray whales are slow swimmers, averaging 3-5 mph (5-8 kph). When traveling, the make shallow dives of 4-5 minutes and then surface to blow 3 or 4 times. Grays also like to breach (leaping out of the water) and spyhop (raising their heads out of the water). These behaviors are not understood but may have to do with breeding or navigation.
In 1857, an American Whaling captain named Charles Melville Scammon heard about the whales’ migration to Baja. Following a pod of whales into a small lagoon, he determined that the traditional harpooning wouldn’t work to kill them. He devised a new method and in the small confines of the lagoons, was able to slaughter hundreds of whales a year, selling their oil and blubber for great profit.
By the 1930’s, nearly all the gray whales had been eliminated. It wasn’t until 1972 when the U.S. government passed the Marine Mammal Protection Act that the gray whale began a comeback. Now, thirty years later, the comeback of the gray whale is considered one of the greatest successes of the environmental movement.
Be sure to check the Gray Whale Fact Sheet and these great Gray Whale Photos.
