Dear Eden,

I live close to a natural area with lots of birds of prey like hawks and eagles. I love to watch them sit in ginormous nests on top of electrical poles. Or swooping around in big circles while they search for a meal.

I talked about why they circle with my friend Jennifer Phillips. She’s a wildlife ecologist at Washington State University. She studies the relationship between birds and the environment.

She told me that birds of prey fly in a circle because they’re riding warm air currents called thermal updrafts or thermals. As the sun heats the Earth, some pockets of air get hotter than others. That warmer air rises. Birds can hop on those warm, rising thermals and ride them. That saves energy.

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