MIGRATE TO WARMER CLIMATES
If it gets too cold where you’re living, simply move somewhere else
As the weather turns colder, food can become scarce, and this causes huge movements of animals in search of fresh supplies. Whole herds regularly migrate across vast distances, running from a gauntlet of predators, while tiny birds set out across the widest oceans. Underneath the waves, enormous creatures migrate. “A lot of whales migrate between the poles and the tropics,” says Dr Rory Wilson, a professor of aquatic biology at Swansea University. “If they migrate to the poles for when it’s summer there, there’s a lot of food around, so they can really gorge themselves.”
Whales, such as the humpback, head to warmer waters to escape the suffocating ice of polar winter and to breed, but there’s actually less food for them nearer the equator. “Because they’re so big, they can fast the rest of the time. They go to the tropics, where there will be a lot less heat lost into the water than if they were in Antarctica,” says Wilson.
You may think that these whales are taking a big risk by delivering their calves in an area where food is so scarce. However, this isn’t the case. “Being born in warmer water is actually a lot easier for the calves, and the mothers can nurse them by using up the reserves they’ve built up over the previous summer,” Wilson explains. “They can feed their calves with a lot of nutrientrich milk. The calves then get bigger and fatter, and are therefore better able to deal with the cold when the time comes to head back to the poles to feed.”