Helping a Falcon in Decline

An American Kestrel sits at the top of a bare tree in early spring.
Keep your eyes peeled! Kestrels like this one at Otto Armleder Memorial Park usually sit at the tippy-top of a tree where they can have an unobstructed view of their surroundings.

The American Kestrel is North America’s smallest falcon. Although they barely outweigh a blue jay, kestrels are fierce predators of rodents, small birds and insects. This species may have been the most common raptor in the parks at one time, but its populations have declined 51% since the North American Breeding Bird Survey began collecting population data in 1966. The cause for decline is likely due to loss of their preferred grassland habitats.

Kestrels are cavity nesters and they don’t excavate their own nests. They will use old woodpecker holes, hollows in trees, crevices in rocks and even nooks and crannies in manmade structures like buildings. In many areas, availability of suitable nest sites may limit their abundance. This is likely true in many areas of Hamilton County where the presence of kestrels is highly associated with the availability of nest boxes. Installing nest boxes for kestrels is one way Great Parks has tried to boost their populations.

Eagle Scout Will Green and fellow Eagle Scouts install cedar wood kestrel boxes earlier this fall. You can see these kestrel boxes at Little Miami Golf Center and Kroger Hills.

This October, volunteer Will Green built and installed five kestrel boxes at the Little Miami Golf Center and Kroger Hills as a part of his Eagle Scout Service Project. He made the nest boxes out of cedar wood and mounted them 10 feet high on sunken wooden poles. Two boxes were installed in the prairie at Kroger Hills and the other three boxes were installed in the grasslands at Little Miami Golf Center. Park staff will be checking these boxes and we’re optimistic that at least a couple will be used in the next few years.

These poles were placed in the middle of the grasslands, because kestrels will not go into areas of dense trees. They are acrobatic and speedy fliers that catch their prey on the wing. They need lots of open space to out-maneuver their quarry.

A group of Eagle Scouts install a kestrel box at a park.

Kestrels occur throughout Hamilton County in low numbers. They are surprisingly adaptable and can even occupy urban areas if there is enough mice, and the area is relatively treeless. They hunt by sitting still and visually scanning for their prey. You can often see them sitting at the tippy-top of a tree or on a telephone wire, where they can have an unobstructed view of their surroundings. If there is not a perch available for a kestrel, they will hover above the ground. It’s quite the spectacle to see because although their wings are rapidly flapping, their head remains absolutely still so they can detect even the slightest movement from a mouse below.

To see where kestrels have been seen near you, check the Species Map on eBird.

Jack Stenger
Conservation Biologist