The American kestrel (Falco sparverius) and the European kestrel (Falco tinnunculus) are two similar-looking falcons found on different continents. Both are small, brightly colored raptors that feed mainly on insects, small mammals, and birds. There are several key differences between these two kestrel species in terms of their physical appearance, habitat, hunting behaviors, breeding, conservation status, and more. Keep reading to learn all about how to distinguish the American kestrel from the European kestrel.
Physical Appearance
The American and European kestrels share a similar colorful plumage pattern, consisting of rusty upperparts with black spotting and barring. However, there are some subtle but noticeable differences in their coloration and markings that allow keen birders to tell them apart:
– The American kestrel has more vivid reddish-brown upperparts compared to the European kestrel’s more subdued, grayish-brown upperparts.
– The American kestrel has solid black spots on its back, while the European kestrel has black dots edged in buff or white.
– The European kestrel has bolder black malar (mustache) stripes and more uniformly barred tail feathers compared to the American kestrel.
– The American kestrel has a rusty yellow tail with a single black subterminal band, while the European kestrel has a rusty tail with numerous narrow black bars.
– The American kestrel has bluer wings compared to the European kestrel.
In terms of size and shape, the European kestrel is larger and stockier than the more slender American kestrel. The European kestrel measures 12-14 inches long with a wingspan of 26-30 inches, while the American kestrel is 9-12 inches long with a 20-24 inch wingspan.
Habitat
The American and European kestrels occupy different continents and habitats:
– The American kestrel is found throughout most of North America up to Alaska and Canada, inhabiting open country such as meadows, grasslands, deserts, parks, and agricultural areas.
– The European kestrel has a wider distribution across Europe, Asia, and Africa. It occupies more varied habitats including open woodlands, agricultural land, cliffs, towns, and urban areas.
– The American kestrel is a year-round resident across much of its range, though northern populations may migrate south for the winter. The European kestrel is partially migratory, with northern populations wintering further south.
– The European kestrel is able to thrive in human-altered environments and is even known to nest on buildings in cities. The American kestrel can also adapt to urbanization but does not do so as readily as its European cousin.
Hunting and Diet
Both kestrel species exhibit similar hunting behaviors and eat similar prey, though there are some subtle differences:
– Their preferred hunting method is perch-hunting – waiting on an elevated perch and scanning for prey below before swooping down to catch it.
– Both kestrels will also hover-hunt, rapidly beating their wings to hover suspended in mid-air while zeroing in on prey. However, the American kestrel hovers more frequently than the larger European kestrel.
– Common prey for both species includes voles, mice, shrews, small birds, reptiles, amphibians, and a wide variety of insects including grasshoppers, dragonflies, beetles and others.
– The European kestrel has a more varied diet that occasionally includes scorpions, bats and small fish, likely because it inhabits a wider range of environments than the American kestrel.
– The American kestrel is known to cache (hide) excess food in crevices or holes for later consumption, a behavior not typical of the European kestrel.
Breeding
The American and European kestrels have some differences when it comes to breeding ecology:
American Kestrel | European Kestrel |
---|---|
Nests in cavities in trees, cliffs, buildings, nest boxes | Nests on cliffs, buildings, sometimes in trees |
Lays 3-7 eggs per clutch | Lays 4-6 eggs per clutch |
Incubation period is 26-32 days | Incubation period is 28-31 days |
Young fledge in 4-5 weeks | Young fledge in 4-6 weeks |
– The American kestrel readily uses artificial nest boxes, enabling conservationists to actively manage and monitor their breeding. The European kestrel is less likely to use nest boxes.
– The American kestrel has a shorter incubation period than the European kestrel.
– Both species produce one brood per year, but the American kestrel is more likely to re-nest after a failed first attempt.
Conservation Status
The American and European kestrels have undergone differing population trends in recent decades:
– The European kestrel is a widespread common species whose numbers remain stable across most of its range. Its IUCN status is Least Concern.
– The American kestrel was once one of the continent’s most common raptors but its numbers have declined by an estimated 50% since the 1960s. Habitat loss is a major threat. Its IUCN status is Near Threatened.
– The use of pesticides, which reduce the kestrel’s insect prey base, may have contributed to the American kestrel’s decline. The European kestrel may be less susceptible as it has a more varied diet.
– Intensive conservation programs in North America aim to restore the American kestrel by providing nest boxes, protecting habitat, and reducing pesticide use. There is no similar large-scale effort for the still-abundant European kestrel.
Key Differences Summary
American Kestrel
– Vivid rufous upperparts with solid black spotting
– Blue-gray wings
– Rusty tail with single black subterminal band
– Smaller and more slender
– Hovers more frequently while hunting
– Caches excess food
– Found in open country across North America
– Has undergone significant population declines
– IUCN status Near Threatened
– Readily uses nest boxes
European Kestrel
– Grayish rufous upperparts with black dots edged in buff
– More uniformly barred tail
– Stockier build
– More varied diet including scorpions, bats, fish
– Found across wider range of habitats in Eurasia and Africa
– Population remains widespread and stable
– IUCN status Least Concern
– Less likely to use nest boxes
Conclusion
In summary, the American and European kestrels share close evolutionary ties and have similar ecological roles on their respective continents. But careful observation reveals key differences in their appearance, habitats, hunting habits, breeding, and conservation outlooks. The American kestrel’s colorful plumage and hovering flight make it a favorite among North American bird watchers, while the widespread European kestrel provides pest control across a broader range of habitats. Protecting grasslands and reducing pesticide use can help safeguard the at-risk American kestrel population. Both of these charismatic falcons provide an important connection to nature for those fortunate to see them in the wild.