Tail end of gray whale migration happening off Sonoma, Mendocino coasts in April, May, June
Just off our coastline, more than 20,000 gray whales travel thousands of miles on their great migration. In autumn, they begin their journey from their feeding grounds in the Arctic Circle to their birthing, mating and nursery waters in the lagoons off Baja California. It’s a trip of five to seven thousand miles, one-way. And the whales do not eat until they return to the Arctic in the spring.
The first to leave the Arctic are the pregnant females. They are followed by those gray whales who will be mating. Those whales not mature enough to mate, will then follow, though some will linger off the coast.
While in the warm waters off Baja, mother whales give birth to their calves. Each mother whale births one calf. The mothers and calves will stay in the lagoons for the calves to gain enough strength to swim the thousands of miles north. The mothers will feed their calves with their rich, calorie-dense milk. They nurse their babies as human mothers nurse their young. Gray whale bodies have many similarities to human bodies.
Fun fact: Newborn calves can drink up to 80 gallons of milk a day.
The first whales to leave Baja and head north in late winter are the newly pregnant females. They swim fast and hard, as they need to reach their feeding ground where they will be eating for two.
The last to leave Baja are the mother/calf pairs, and that is what is occurring now. April, May and early June are the perfect times to whale watch, as the mother/calf pairs are closer to shore due to the current, and the whales come up more often for their offspring to breathe.
You look for whales by seeing their blow. It’s the exhalation of air that looks like a puff of whitewater just over the ocean. Next, you might see their backs arcing through the water, followed by their distinctive, notched tail.
The very best places to whale watch are found where a lighthouse is perched. But this time of year, any bluff or beach can bring you a thrilling gray whale sighting.
Other activity to look for is breaching, and the calves seem to do this more than their mothers. Gray whales will also spy hop. This is when a whale pokes her head straight up out of the water. One theory is the whale is listening for the surf break, as a way of keeping her on course. Another theory is the whale just wants to take a look around. Perhaps gray whales are interested in a sighting of us.
Whale expert Scott Mercer, along with his wife Teresa, has been coming to the Mendocino Coast for four years from his home in Maine to record the numbers of gray whales passing by, and to study them. Mercer is the author of "Whalehead Nation, Creating and Keeping an Environmental Ethic in Children."
Mercer points out that from the lagoons to the Point Arena Lighthouse is 1000 to 1200 miles. Gray whales travel between three and five mph, and stop to rest if they want. Mothers with a nursing calf in tow will travel north even slower.
When asked what has surprised him during this project, Mercer said, “I learned not all calves are born in Baja, that dozens are born off the Southern California coast. I was also interested to learn that the groups gray whales travel in are very temporary. We see them form, split up, and reform each day.”