Gray Whale Migration
Winter: December, January, February
In the Mating and Calving Lagoons
Since December, gray whales have been arriving in the four calving and mating lagoons of Mexico's Baja California coast. (Click on the map dots to read more about each lagoon.) Most of the births occur from early January to the end of February, although a few babies each year are born during their mother's migration south.
females and those with calves concentrate in the inner lagoons, farthest
from the open sea. A newborn gray whale calf is around 15 feet long
birth and weighs from 1500 to 2000 pounds. In some cases, another gray
whale called an auntie helps during the birth. The auntie may help
mother above the water so the baby can be born headfirst into the air.
The auntie or the mother will also push to the surface a calf born
so this baby mammal can take its first breath of air. Within minutes
the baby is gaining strength and swimming. It has a lot of growing
to do in
the next 2-4 months, when it will need to swim the 5000 miles (or more!)
to its summer home and feeding grounds.
A new baby gray's flukes and flippers are very floppy at first. Later they'll become rigid, but for now it is very difficult for these newborns to swim fast enough to keep up with an adult. The mothers move very slowly. They are very protective of their young. Once their flukes and flippers have gained strength, the calves begin to explore the lagoon. Mothers carefully swim with their babies around the lagoon.
The warmer waters of Baja Mexico's shallow lagoons are ideal nurseries. The warmer water helps newborns to conserve body heat—a good thing because they are born lean and fairly blubberless. The calves nurse for around 6 months, during which time the mother provides up to 50 gallons of milk each day. The thick, rich milk contains 53% fat, helping calves gain 60 to 70 pounds or more—daily! They are building up blubber for their cold trip north.
Meanwhile, whales in the lagoons continue to enchant and entertain hundreds of visiting whale watchers. Tour guide Keith Jones says: "We have been blessed with one trip after the other where whales come right up to the boat." Do you wonder what it would be like to float in the panga (boat) and have a huge gray whale mother and her curious baby glide up to or under it? Some lucky teens from Knoxville, Iowa show what it’s like. If you can't imagine kissing a baby whale, be there with our video clip!
By the end of December or first of January, gray whales are traveling both ways. A few of the earliest arrivals in the lagoons—males who are done mating and whales too young to mate—are already starting their journey north. Into February gray whales are still plowing south in bigger numbers than the few whales heading north. But usually by mid-February to early March, the migration reaches a point called the turnaround: more whales are headed north than south. For most gray whales, the urge to migrate south fades in mid-February. (Whales going south in March and April are probably just detouring temporarily from the northbound migration. Could they be turning back to look for other whales they had been traveling with earlier?)
By mid-February, newly-pregnant females leave the lagoons to begin the northward migration. They are soon followed by the males and the juveniles of previous years. Last to leave are the new mothers and their calves. They sometimes stay as late as May or June.