Book 23, Question 34
Why Can Ostriches and Penguins Not Fly?
Ostriches and penguins are birds. But neither one can fly. Why not? An ostrich can run about forty-five miles per hour. Penguin wings work like flippers.
More fun facts
- Ostrich wing feathers are fluffy and fancy instead of tightly hooked together like the feathers of flying birds.
- Among seabirds, flightlessness has evolved separately at least five times.
- Scientists think a wing built to be great for swimming underwater cannot also be great for flying.
- To test this, they studied guillemots on Coats Island in northern Canada, which dive like penguins but can still fly.
- Guillemots used much less energy than most other birds while diving.
- But flying took 31 times the energy they used at rest, the highest ever reported for a flying bird.
- As penguin wings became better and better flippers, flying cost more and more energy, until penguins stopped flying altogether.
Sources: academy.allaboutbirds.org, abdn.ac.uk, National Institutes of Health
Questions kids ask
Are penguins the only flightless birds that dive with their wings?
No. Some large auks that are now extinct also dived with their wings and could not fly.