Why can't penguins fly?

If you’re a bird, your ability to fly is super useful. It means you can make a quick getaway when you spot danger, head off to a nice warm country for the winter and keep a lookout for your prey. Those are big advantages. Penguins are birds too – so why can’t they fly?

Little flippers

Penguins eat lots of fish, crustaceans and small octopuses. To get at their prey – and to avoid the seals, killer whales and sharks that like to eat penguins – they evolved to be really good at swimming.

Their wings got smaller and started to look more like fins, and their bones got heavier. Today, penguins’ bodies are so heavy that they can’t get off the ground. Now their wings work like flippers to help them ‘fly’ through water instead.

Twenty minutes under water

That’s not all: penguins’ muscles evolved more myoglobin to help them stay under water for longer. Myoglobin is a protein that makes sure muscles get enough oxygen.

Penguins can stay under water for 20 minutes without having to come up for air, and they can reach speeds of over 14 kilometres per hour (kph). Most humans can only manage 4 kph.

Answered by Naomi Vreeburg