Migrating Cranes
Sandhill cranes often migrate very high in the sky where you can't easily see them. Instead of seeing them, you can hear their loud, rolling, trumpet cries, even when they're flying as high as 2.5 miles up.

"Twelve separate vees of sandhill cranes flew over our neighborhood today. They were making a lot of noise. They were flying at 1000 feet AGL (above ground level), or possibly a bit higher. The total number was between 100 and 200 birds, and they were headed south." Nov. 27, 2014   Madison, Wisconsin

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