Not so long ago, on a drive down a rural road in Minnesota you'd often see an American kestrel perched on a power line, watching for a dragonfly or small rodent to pass beneath.
If you were really lucky, you'd spot this smallest member of the falcon family flapping its wings in its unusual hovering flight as it watched for prey.
Such sights are becoming increasingly rare.
These handsome little raptors, about the size of a mourning dove, are suffering a long-term and widespread population decline. No one's quite sure why, but their numbers have dropped by 73 percent in Minnesota over the past 50 years. In New England, they've dropped more than 90 percent.
Loss of good habitat for finding food is probably a major factor in their decline, as is a lack of nesting sites in dead trees. Other factors might include the effects of our changing climate, environmental toxins and competition from other cavity nesters, like starlings and house sparrows.
A dedicated group of people, known as the American Kestrel Partnership (kestrel.peregrinefund.org) is working to help this species recover by building and putting up nest boxes. The same approach has been used successfully to bring back bluebird populations.
Julian Sellers spends a great deal of time each spring and summer on his "kestrel trail, monitoring nest boxes in several parks and preserves around the metro area.
"About five years ago I began to notice the general scarcity of kestrels along highways and country roads where they used to be common," said Sellers, a member of the St. Paul Audubon Society.