24 Whale Migrations

Whale Migrations written by Rachel Walker

Every spring, hungry, grey whales swim north. They swim non-stop, from the warm waters of Mexico, along the coast of North America, then on to the icy-cold waters of the Arctic. The cold Arctic Ocean is their summer feeding grounds.

baleen All summer, the grey whales eat as much as they can. They don't have teeth. Instead, grey whales have baleen plates. Baleen is more like your fingernails than your teeth. Baleen works a bit like a comb, to catch the food, in the gaps.

krill Grey whales are the only bottom-feeding whales. They dive right down to the bottom of the sea and take large mouthfuls of sand and water from the sea-floor. Next, they spit out all of the sand and water back into the ocean, through the gaps in their baleen. This leaves lots of little bits of food, called krill, trapped in their mouths, for them to eat. It's delicious for the whales!

Mexico As the seasons change again, the cold waters in the Arctic begin to slowly freeze and ice-over. There is less sunlight and less food, so the grey whales start their return swim south. As they migrate 8,000 kilometers, they swim the long journey back past the coast of North America, and return to the warm waters of Mexico. This long migration takes the whales almost two months! Here, in the warm Mexican waters, the grey whales have their calves.

While they stay in the warm, safe, and calm waters of Mexico, the mother whales give birth to their baby calves. The baby whales, glossy skin feels like wet rubber. For the first few months of their lives, the whale calves drink so much mothers, milk, that they grow bigger and stronger each day.