How can a convection current enable a hawk or eagle to soar upward without flapping its wings?

1 Answer
Oct 24, 2016

Convection currentls cause warm air to move upwards.

Explanation:

Warm air rizes and is replaced by cooler air from the surrounding area. The warm air eventually cools off, falling down and replacing more warm air. This causes a constant upward flow sometimes called a thermal that allows large birds to soar without effort.

The image below shows a glider rather than a bird, but the same principles apply:
http://www.aerospaceweb.org/question/nature/q0253.shtml