Whale offspring, like cow babies, are called calves. In terms of human knowledge, however, we are quite limited. Scientists do not actually know most biological factors concerning the majority of whales and their babies!
Whales give birth to their babies instead of laying eggs. This is a characteristic of most mammals (though there are a few strange mammals in Australia like the platypus and echidna that do lay eggs).
But wait! I thought whales lived in the ocean all the time and had to breathe -- what happens to the babies?
The babies have to learn to swim the minute they are born so they can get to the surface of the water and take their first big breath. Their mom helps to nudge them up, but it’s important that the babies help. Sadly, some calves don’t make it and drown when they are born. Most of it make it though.
Killer whales, who travel in groups called pods, actually help each other with the birthing process. An aunt or sister will help the new mom nudge her baby to the surface for its first breath.
Where do they go to have birth their calves? What migration routes do they take? Though scientists do know that migrations usually take place between the summer feeding months and the winter calving months, the routes are generally unknown. Regardless, we do know certain aspects of whale species' offspring. Scientists speculate that Orcas, for example, birth calves at around the age of 11. Humpbacks and their calves come back to the same summer feeding area every year - scientists think that whales remember where and when they can find lots of food. They even think that the mom whales pass this information on to their calves (they listen to their mothers!).
A Right whale female will only give birth once every 5 years! By comparison, Gray whales birth more than double that amount (for every 5 Right whale calves born, there are approximately 13 Gray whale calves) - this has obviously caused some serious population problems concerning Right whales, as a staggering 50% only survive to maturity.