Mexico’s Sea of Cortez is home to one-third of the world’s whale and dolphin species. Twelve species of annual whales live in these waters, including the blue whale (the largest animal in the world), humpback whales and gray whales. Gray whales are relatively large - about twice the length of an Orca (killer whale) and half the length of the enormous blue whale. Most adult gray whales are about ten to thirteen meters (35 to 45 feet) long, and weigh twenty-two to thirty-eight tonnes (20 to 35 tons), with females tending to be larger than the males. Named for their medium gray color beneath the water, which is marbled with lighter patches, gray whales appear to be a whitish-blue color at the water’s surface. Each whale has a unique skin pigmentation color which allows individuals to be identified, and these patterns often include round white markings that result from barnacles that have fallen off.

Undergoing one of the longest animal migrations in the world, gray whales inhabit the chilly waters of the Bering Sea (off the coast of Alaska) in the summer, and migrate to their annual birthing grounds in winter - the warm lagoons on the coast of Baja California Sur, Mexico, some 6,000 kilometers (4,000 miles) to the south. Exactly why the gray whale and many other whale species travel to warmer climes to breed and give birth is unknown. Yet, each year, gray whales depart from the Bering Sea in October, and by December, they are usually between Monterey and San Diego, where thousands of residents watch up to 200 whales a day stream past their shores. They reach the central coast of Baja by late December, where half of the females mate and the other half give birth. Each year, a few stragglers can be seen arriving as late as February. These slowpokes encounter northbound whales returning from Baja and often hit the brakes, turn around and join them. (more…)

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The Gray Whale or Grey Whale (Eschrichtius robustus) is a whale that travels between feeding and breeding grounds yearly. It reaches a length of about 16 meters (52 ft), a weight of 36 tons and an age of 50–60 years. Gray Whales were once called Devil Fish because of their fighting behavior when hunted. The Gray Whale is the sole species in the genus Eschrichtius, which in turn is the sole genus in the family Eschrichtiidae. This animal is one of the oldest species of mammals, having been on Earth for about 30 million years. In the remote past it was preyed upon by Megalodon sharks (which are now extinct). Gray Whales are distributed in a North-eastern Pacific (American) population and critically endangered North-western Pacific (Asian) population. A third population in the North Atlantic became extinct in the 17th century.

In the fall, the Eastern Pacific, or California, Gray Whale starts a 2–3 month, 8,000–11,000 km trip south along the west coast of Canada, the United States and Mexico. The animals travel in small groups. The destinations of the whales are the coastal waters of Baja California and the southern Gulf of California, where they breed and the young are born. The breeding behavior is complex and often involves three or more animals. The gestation period is about one year, and females have calves every other year. The calf is born tail first and measures about 4 meters in length. It is believed that the shallow waters in the lagoons there protect the newborn from sharks. After several weeks, the return trip starts. This round trip of 16,000–22,000 km, at an average speed of 10 km/h, is believed to be the longest yearly migration of any mammal. A whale watching industry provides ecotourists and marine mammal enthusiasts the opportunity to see groups of Gray Whales as they pass by on their migration. 

The migration route of the Eastern Pacific, or California, Gray Whale is often described as the longest known mammal migration. Beginning in the Bering and Chukchi seas and ending in the warm-water lagoons of Mexico’s Baja peninsula, their round trip journey moves them through 12,500 miles of coastline. This journey begins each October as the northern ice pushes southward. Traveling both night and day, Gray whales average approximately 120 km (80 miles) per day. By mid-December to early January, the majority of the Gray whales are usually found between Monterey and San Diego, where they are often seen from shore. By late December to early January, the first of the Gray Whales begin to arrive the calving lagoons of Baja. These first whales to arrive are usually pregnant mothers that look for the protection of the lagoons to give birth to their calves, along with single females seeking out male companions in order to mate. By mid-February to mid-March the bulk of the Gray Whales have arrived the lagoons. It is at this time that the lagoons are filled to capacity with nursing, calving and mating Gray Whales. The three primary lagoons that the whales seek in Baja California are Scammon's (named after a notorious whale hunter in the 1850's who discovered the lagoons and later became one of the first protectors of the Greys), San Ignacio and Magdalena. As noted, the Greys were called the devil fish until the early 1970's when a fisherman in the Laguna San Ignacio named Pachico Mayoral (although terrified to death) reached out and touched a Grey mother that kept approaching his boat. Today the whales in Laguna San Ignacio are protected but it is possible to visit a whale camp there and have the same experience that Pachico had. Throughout February and March, the first Gray Whales to leave the lagoons are the males and single females. Once they have mated, they will begin the trek back north to their summer feeding grounds in the Bering and Chukchi seas. Pregnant females and nursing mothers with their newborn calves are the last to leave the lagoons. They leave only when their calves are ready for the journey, which is usually from late March to mid-April. Often there are still a few lingering Gray Whale mothers with their young calves in the lagoons well into May. A population of about 200 gray whales stay along the Oregon coast throughout the summer, not making the farther trip to Alaska waters. 

Credits: Wikipedia