Why is Cool Air Best?
Joe Duff

Photo Operation Migration

Why is cool air best for Whooping Crane migration? Senior Pilot Joe Duff of Operation Migration answers.

Joe Duff of Operation Migration

Cooler air is more dense than warmer air. Warm air can actually hold more moisture because molecules are farther apart, making more room for moisture. Cold air is dense and compact; it's "thicker," so when you breathe in you get more oxygen. Thicker air also means there's more for a crane's wings to push against. When the propeller spins there's more thrust. When the wing flies there's more lift to it. The aircraft works better because the engine works better, the propeller works better, and the wing works better. And for the birds, their wings work better too. They get more oxygen and it's easier to cool their bodies. They don't overheat.

It's just a lot easier to fly in cold air. Cold air is really a big factor in the birds' endurance. Warm air wears them out very quickly. You see them panting quickly, their tongues come out, they start to splay their feet to help cool their bodies, and they just can't fly."

Try This! Journal Questions
  • Summarize Joe's answer in your own words.
  • List behaviors that show a crane is getting tired during flight. Why do you think that splaying their feet (spreading their toes apart) helps cranes to cool off?
  • What behaviors show YOU are tired when you exercise hard? Then how do you cool off?


Journey North is pleased to feature this educational adventure made possible by the
Whooping Crane Eastern Partnership (WCEP).