Along the Path: A Young Person’s Guide to Exploring Nature
By Susan Rothrock Deo
I love to go a-wandering/ Along the mountain track/ And as I go, I love to sing/ My knapsack on my back.
Do you like to wander? We land mammals wander here on terra firma. Did you know there are also animals that wander the seas? Our famous one is the California gray whale.
Gray whales don’t carry knapsacks, but they do have a thick layer of blubber (fat) that supplies the food energy they need for migration. The gray whale has one of the longest migrations, over 10,000 miles round trip! In summer they live in the Bering and Chukchi Seas north of Alaska, fattening up for their journey. In fall, they travel south to Baja California in Mexico. In Southern California we start seeing them in December, though some of the younger whales may wander in and out of the area earlier. The whales spend winter in the warm lagoons of Baja where they breed and give birth. In spring they swim back north to their feeding grounds. This time they hug the shore. The favorable ocean currents make swimming easier for the little ones. Being closer to shore and the kelp forests helps moms protect their babies from ocean predators like orcas and sharks.
In Baja the whales are relaxed, curious and friendly. They come up to small boats and might even allow whale watchers to rub their foreheads or feel the smooth firmness of their skin. Sometimes they just watch you with one baseball-sized eye. (Their eyes are far enough on the side that it’s hard to see you with both eyes at once.)
In Alaska, the whales are all about the business of eating. During migration and in the lagoons they rarely eat. Gray whales are the only great whales that scoop their food off the muddy ocean bottom. They eat primarily amphipods, cousins of shrimp. Other species take great mouthfuls of water to feed.
Gray whales are mammals like you and me. They feed their babies mother’s milk, are warm blooded, breathe air and have hair. After birth, babies must surface to breathe within 15 seconds. They learn to swim within 30 minutes. Their mother’s milk is 50-60% fat so they can grow big quickly.
Gray whale mothers have mammary slits rather than nipples. Whale calves have no lips so they can’t suckle like human babies. It’s hard to drink underwater so mom squirts the milk right into baby’s mouth and the calf’s well-designed tongue catches it all. An adult gray whale’s tongue is about the size of a compact car!
Whales’ nostrils are ON TOP of their heads so they don’t have to lift much of their body out of the water to take a breath. The whale surfaces and breathes out the “blow” we see. (The gray whale’s blow is heart shaped and twice as tall as a human.) Then they breathe in and take a shallow dive. After three or four of these they take a deep dive and stay down about 20 minutes.
Whales only have a few hairs. On land, fur helps keep mammals warm by trapping an insulating layer of air between the fur and the animal’s skin. But the weight of the ocean water would flatten fur and leave no room for insulating air. Fur would also cause friction when swimming. Instead, their thick layer of blubber keeps them warm and their smooth skin helps them speed through the water.
I hope you get to see some wandering whales this winter!