Eli5 : why are bigger birds generally faster than smaller birds?

Question

The way I think about it, smaller birds have less weight and less wind resistance. Shouldn’t that mean they would be faster?

In: 7

Answer 1

Really comes down to power. Bigger birds have larger and more powerful wings and the size to weight ratio is in their favor.

You can also think about it with cars. There are very small very light cars but they are not faster than big heavy super powerful engines

A Bugatti is a big and heavy car but it’s much faster than a ford fiesta