How can birds still fly if they have to constantly eat to have enough energy to fly? Doesn’t eating make them so heavy that they need even more energy to keep flying?

Question

When I watch the birds at the feeding station in my garden, I notice that individual birds often eat a lot at once. Doesn’t all that food make them so heavy that they need more energy/food to fly than they can carry in flight?

In: Biology

Answer 1

Birds that glide are excellent at “reading” air currents and thermal updrafts. They use this knowledge to use as little energy as possible. It doesn’t always work but they’ve had millions of years to evolve.