The American Kestrel and the sparrow hawk are two different species of raptors found in North America and Europe respectively. At first glance, they may appear quite similar due to their small size and coloring, leading some people to mistakenly believe they are the same bird. However, upon closer inspection there are several key differences between these two birds of prey.
Size and Appearance
The most noticeable difference between the American Kestrel and the sparrow hawk is their size. The American Kestrel is North America’s smallest falcon, with a body length of only 9-12 inches and a wingspan of 20-24 inches. The male kestrel has colorful plumage, with a blue-gray head and wings contrasting with its rusty red back and tail. The female kestrel is slightly larger than the male and has brown barred plumage on its back and wings.
In comparison, the Eurasian sparrow hawk is distinctly larger, with a body length of 12-16 inches and a wingspan of 26-31 inches. Both male and female sparrow hawks have similar plumage consisting of bluish-gray upperparts and barred underparts. Their most distinctive feature is their orange eyes and yellow feet.
Size Comparison
| Bird | Body Length | Wingspan |
|---|---|---|
| American Kestrel | 9-12 inches | 20-24 inches |
| Eurasian Sparrow Hawk | 12-16 inches | 26-31 inches |
As the table shows, the sparrow hawk is distinctly larger than the American kestrel in both body length and wingspan. This size difference is one of the most reliable ways to distinguish between these two raptors when seen in the field.
Habitat and Range
The habitats and geographic ranges of these two hawks also differ significantly. The American Kestrel is widely distributed across most of North America, ranging from central Alaska down through Canada and the United States into Mexico. It occupies a variety of open and semi-open habitats including meadows, grasslands, deserts, parks, and agricultural areas.
The Eurasian Sparrow Hawk has a range confined to Europe and Asia. It primarily inhabits open woodland and forest edges across its range, particularly favoring lowland woodlands interspersed with open areas. Unlike the widespread American Kestrel, the Sparrow Hawk has a patchier distribution across Europe and Asia.
Range Map
| Bird | Range |
|---|---|
| American Kestrel | Most of North America from Alaska to Mexico |
| Eurasian Sparrow Hawk | Europe and Asia |
The restricted range of the Eurasian Sparrow Hawk compared to the widespread American Kestrel is another factor that prevents these species from being mistaken, provided location is taken into account.
Hunting and Prey
Differences in preferred habitat type between the American Kestrel and Eurasian Sparrow Hawk lead to differences in their hunting strategies and choice of prey.
The American Kestrel is an opportunistic hunter that frequents open country and grasslands. It primarily hunts small mammals such as mice, voles, shrews, and bats, but will also take insects, small birds, and reptiles. It often hovers in place while hunting, using its keen eyesight to spot prey on the ground below.
In contrast, the Eurasian Sparrow Hawk is more adapted to hunting in wooded areas. Its main prey consists of small woodland birds like sparrows, finches, tits, and thrushes. Unlike the hovering American Kestrel, the Sparrow Hawk employs quick dashes and short pursuits to capture birds in flight. It also takes fewer mammals than the American Kestrel.
Prey Preferences
| Bird | Primary Prey |
|---|---|
| American Kestrel | Small mammals, insects, small birds |
| Eurasian Sparrow Hawk | Small woodland birds |
The differing diets and hunting styles of these two hawks is an adaptation to their preferred habitats, and is another distinction that can be made between the American Kestrel and the Eurasian Sparrow Hawk.
Taxonomy and Genetics
While they may appear similar on the surface, the American Kestrel and Eurasian Sparrow Hawk are not actually very closely related. This is evidenced by differences in their taxonomy and genetics.
The American Kestrel is a member of the genus Falco in the falcon family Falconidae. Its closest relatives are other North American falcon species like the Merlin and Prairie Falcon. The Eurasian Sparrow Hawk belongs to a different genus Accipiter in the Accipitridae hawk family, along with other Accipiter hawks such as the Northern Goshawk and Sharp-shinned Hawk.
Genetic studies have shown that the American Kestrel and Eurasian Sparrow Hawk are not sister species, and their most recent common ancestor lived over 20 million years ago. This long period of separation and independent evolution has led to many genetic and morphological differences between the two species.
Taxonomic Classification
| Bird | Genus | Family |
|---|---|---|
| American Kestrel | Falco | Falconidae (falcons) |
| Eurasian Sparrow Hawk | Accipiter | Accipitridae (hawks) |
The classification of the American Kestrel and Eurasian Sparrow Hawk in separate bird families highlights their evolutionary divergence and confirms they are distinct species.
Behavioral Differences
Some aspects of behavior also differ between the American Kestrel and the Eurasian Sparrow Hawk.
American Kestrels are highly territorial during the breeding season, and defend their nesting sites aggressively. They are also semi-colonial, and will nest in loose groups in favorable habitat. The male performs aerobatic display flights during courtship. Outside of breeding they are often seen perched prominently on wires, poles, and dead branches.
Eurasian Sparrow Hawks are not colonial nesters, maintaining distinct breeding territories. They utilize a wider variety of nest sites including old crow and squirrel nests, not just cavities. Sparrow Hawks have a slower, more fluttering flight style compared to the American Kestrel’s direct and powerful wingbeats. The two species also have differing calls and vocalizations.
Behavioral Differences
| Behavior | American Kestrel | Eurasian Sparrow Hawk |
|---|---|---|
| Nesting | Semi-colonial, cavities | Territorial, variety of sites |
| Flight style | Direct, powerful | Fluttering |
| Display | Aerobatic flights | No aerial display |
Subtle differences in aspects of behavior like nesting, flight, and display further distinguish the American Kestrel from the Eurasian Sparrow Hawk.
Conclusion
In summary, while the American Kestrel and Eurasian Sparrow Hawk share some superficial similarities in appearance and prey selection, they differ significantly in terms of size, geographic distribution, habitat preferences, genetics, taxonomy, and behavior. The American Kestrel is a small falcon native to North America that inhabits open country and takes a varied diet of small prey. The Eurasian Sparrow Hawk is a larger accipiter hawk found across Europe and Asia, more adapted to woodland hunting for birds. These two species may appear related at first glance, but are actually quite distinct raptors belonging to separate genus and families.
So in answer to the original question “Is an American Kestrel the same as a sparrow hawk?”, the clear answer is no. The American Kestrel (Falco sparverius) and the Eurasian Sparrow Hawk (Accipiter nisus) are different species with distinct characteristics and evolutionary histories. Any similarities in appearance or prey selection are the result of convergent evolution to fit similar small predator niches, rather than close relationship. While tricky to distinguish at first, knowledgeable birders can identify a number of consistent differences that set these two raptors apart in the field.
