Gravel Nest

American Kestrels are cavity nesters. They find holes in trees or utilize nest boxes to keep their eggs safe. Then why does Aldo the American Kestrel make a nest on the ground every year? He creates a depression in the gravel and chatters noisily, bowing up and down, to advertise it to potential mates. Meanwhile, his enclosed hutch remains relatively unused during breeding season. 

I once worked with another male ambassador kestrel that tried to nest on the ground. Curious!

Both of these kestrels are human imprints - they were raised by people. I wondered recently whether that impacted their nesting preferences. Maybe the people didn't raise these birds in a cavity. Perhaps they were growing up on a flat, open surface, like someone's kitchen counter or a rehab facility's clinic. If they imprinted on their caretakers, did they also imprint on their nest type? That's just my speculation - what do you think?