Kestrel vs Barn Owl
As you can see from the video (below) by British wildlife artist and expert Robert E. Fuller, kestrels and barn owls do not always get along. However, if you were to draw a Venn diagram with one circle being the characteristics, habitat and diet of the barn owl and the other being that of the kestrel, you'd see significant overlap.
Unlike opposites that attract, kestrels and barn owls would seem to be a case of familiarity breeding contempt in the natural world. But the kind confrontational behavior seen in the video clip isn't based on deep animosity or some long-held grudge that manifests across time and through generations.
When it comes to the kestrel vs barn owl divide, nothing sparks conflict quite like nesting behavior.
While there is evidence that, in some cases, kestrels and barn owls can coexist and even occasionally cohabitate, it's not the norm for both species. Kestrels, once widely known as "sparrow hawks" are members of the falcon family. In fact, the American kestrel is the smallest of the North American falcons.
Like other falcons, kestrels are very attractive birds and magnificent flyers, exhibiting a truly amazing level of control while in the air. They use rapid wingbeats to hover over potential prey and while they are highly visible hunters, that visibility does not detrimentally affect their success when capturing the rodents that make up the bulk of their diets. What they lack in stealth, they more than make up for in lethality.
Mighty hunters though they may be, when it comes time to find a mate and rear a family, kestrels aren't exactly homemakers. They take no pride in building nests—in fact, they don't do it at all. Kestrels are cavity nesters, meaning they take up residence in crevices, holes in trees or even the nests of other birds, and despite their small size, they tend to prefer a roomy domicile. Kestrels are like the couch surfers of the raptor world—except they don't just want to crash on your couch for a few weeks; they want to kick you out of your home, take over the entire thing and raise their children there. What kestrel nesting lacks in politeness, it makes up for in sheer territorial audacity.
Barn Owl Nests
As mentioned, barn owls and kestrels have many points of commonality. They both dine on similar prey, often exist in the same area and are under the same pressures in terms of human-made development encroaching on their habitat and diminishing their numbers.
And much like kestrels, barn owls prefer to nest in crevices. They're not quite as picky about where they decide to bring up baby, and along with natural nesting cavities, barn owl nests can be found in many kinds of human structures such as houses, church steeples, haystacks and, of course, the barn lofts from which they draw their names. Barn owl nesting behavior is such that they can coexist more easily near human activity, which is why their nests are sometimes found in strange places, most notably on drive-in movie screens.
Since they both prefer to make their homes in crevices and cavities, barn owls and kestrels can come into conflict when they have staked a claim to the same piece of property. And as the video illustrates, when a kestrel wants a spot that a barn owl has designs on, one species does not exactly roll out the welcome mat for the other.
For the Birds: The Owl and Kestrel Nest Box
Given the diminishment of the populations of barn owls and kestrels due to encroachment on their joint habitat by human development, and their value as species that help to control rodent populations, in recent years, efforts have been made to increase their nesting sites. In doing so, the hope is to stabilize the populations of these bird species in some areas, while growing their numbers in others.
For birds that build their own nests, providing nesting materials and appropriate sites can be a complicated affair given that what birds build their nests from and where they prefer to build them varies from species to species.
Because kestrels and barn owls are both cavity nesters, giving one or the other (or both) a roof over their head is as simple as building an owl and kestrel nest box. Both species are easily lured to such structures and will often return to the same nest box year after year. Indeed, nest boxes are one of the simpler strategies naturalists and birders have deployed to help give barn owls and kestrels soft places to land and safe places to raise their offspring. In doing so they can stabilize or supplement populations of these beautiful birds in places where their rodent-control skills are needed. If you live in or near the habitats of barn owls or kestrels, building a nest box of your own is as simple as Googling “owl and kestrel nest box” for plans and instructions.
While they may provide a home sweet home, nesting boxes do not bridge the kestrel vs barn owl divide in terms of who may be a prime box's rightful owner. Turns out that real estate issues are not limited to humans. However, as we saw from Fuller's wildlife video, kestrels and barn owls have ways of working these things out, even if the solution to the problem isn't always amicable.