I photographed this male American Kestrel a few days ago at Farmington Bay WMA as it flew out of a nest box. It seemed strange to see the kestrel checking out the nest box at this time of the year but they do check into them to see if any nest maintenance needs to be done. Or perhaps it is because the weather has been so odd.
A little information about nest selection process for American Kestrels from allaboutbirds.org:
American Kestrels nest in cavities, although they lack the ability to excavate their own. They rely on old woodpecker holes, natural tree hollows, rock crevices, and nooks in buildings and other human-built structures. The male searches for possible nest cavities. When he’s found suitable candidates, he shows them to the female, who makes the final choice. Typically, nest sites are in trees along wood edges or in the middle of open ground. American Kestrels take readily to nest boxes.