Many years ago, I built and set out several kestrel boxes near our Rimbey-area farm. I was thrilled when one pair took up residence, offering me the opportunity to watch the adults and see the nestlings up close. More recently, I have appreciated the opportunity to check boxes with other kestrel enthusiasts.
How ugly the young are when first hatched, and how quickly they grow. Unique among birds, nestling kestrels have a very creative way of disposing of their feces; they back up, lift their tails and squirt it on the roof and walls of the cavity! I remember being shocked and surprised to open up a box with week-old chicks. I was taken aback by both their cute-but-ugly faces and the smelly fecal wallpaper they were creating inside the box.
Although kestrels will take the odd songbird, they eat mostly grasshoppers, beetles, dragonflies, spiders, butterflies, moths and small mammals. Interestingly, they can use their ability to see ultraviolet light to track voles and other small mammals by following urine trails. If hunting is good, they will cache surplus prey in/on hiding spots such as bushes, grassy clumps, tree limbs and cavities. Because of their small size, they often fall prey to larger hawks and owls.
American kestrels are migrants, usually arriving in Alberta each spring in April and then departing in October. Overwintering records are rare, so I
was grateful for the opportunity to watch and photograph a lone male kestrel that decided to hang around a subdivision south of Calgary a couple winters ago. Residents in this subdivision fed a large population of house sparrows, so this bird decided (either by choice or because of some ailment) that it would just stay behind and avail itself of easy pickings. Each day, it took a sparrow or two and, according to the bird watchers in the area, thrived for the entire winter.
If you are interested in setting out nestboxes for American Kestrels, the Alberta Conservation Association has an excellent downloadable booklet with all the details (http://www.ab-conservation.com/downloads/educational_materials/brochures/nest_box_guide_and_instructions.pdf).