Look up

I was outside when I heard a "hrrooo, hroooo" sound coming from the sky. You can listen to it here : http://www.birds.cornell.edu/AllAboutBirds/audio/Sandhill_Crane.html We are hearing birds, big birds flying over our house in their Spring migration. Where are they?

Oh there they are - do you see them? They are flying in a sort of a "v" formation. These are Sandhill Cranes. We would never see them if they didn't call out to each other as they fly.