The Eurasian Kestrel (Falco tinnunculus) and Sparrowhawk (Accipiter nisus) are two fairly widespread species of birds found in the UK and across most parts of Eurasia. They live in similar habitats and from afar can be hard to distinguish, so what are the key differences between a kestrel and a sparrowhawk?
Generally speaking, the best way to tell the difference between Kestrels and Sparrowhawks is their plumage. Sparrowhawks have a plumage that overall appear more greyish, whereas Kestrels have a warmer looking plumage consisting mainly of buff and browns. In flight, the shape and colour of the tail is an excellent way to identify each bird, as sparrowhawks have a more 'V' shaped tail with broad dark bands equal in width. The tail of a kestrel is much more rounded and fan-shaped when compared to a sparrowhawk. Male kestrels only have one dark band at the end, and females and juveniles have many narrow bands.
These are not the only ways to tell the difference between both birds, so continue reading for some more ways to differentiate between sparrowhawks and the common kestrel.
Kestrel in flight, from below
Sparrowhawk in flight, from below
Both kestrels and sparrowhawks, on average, are highly similar in size. Still, if you compare the average length and weight, sparrowhawks are usually slightly larger, although the difference is negligible and only by around 5cm and 40 grams.
In both species, and like all birds of prey, females are larger than males.
European Kestrel measurements
Common Kestrel or Rock Kestrel
In the UK, kestrels have a higher population than sparrowhawk, but this doesn't mean you're always more likely to see kestrels. In fact, you're generally much more likely to see a sparrowhawk in your garden, as they are more common visitors. Kestrels do sometimes come into gardens, but less frequently.
Both Sparrowhawks and Kestrels can be found and spotted all year round.
Sparrowhawks are often spotted in towns and cities, as well as rural areas, gardens and open countryside. They can be found in most parts of the country in the UK, other than some parts of the Scottish Highlands, the Western Isles and Shetland.
Kestrels also have a broad and similar variety of habitats but are mostly spotted hovering up high in the countryside and along motorways, on the lookout for prey. This isn't to say that they aren't found in towns and cities too, but it's generally less common; however, kestrels have adapted well to man-made environments.
Once upon a time, Kestrels were the most common bird of prey in the UK. Recent declines mean that Kestrels are now the second most common bird of prey and has been taken over by the thriving Common Buzzard population. These recent declines mean they have an amber status in the UK. It's thought that the majority of the recent decline is down to starvation, particularly in juveniles during their first autumn and winter. Other reasons for the decline are shooting, poisoning, accidents, collisions and disease.
If you manage to be close enough to see the eyes, adult sparrowhawks have piercing yellow or orange irises, whereas kestrels have dark irises.
Like most birds of prey, both species have excellent eyesight and are capable of spotting prey from great heights and distances.
The proportionate size and shape of the head is another good way to tell the difference, as sparrowhawks have fairly small-looking heads. Kestrels have heads that are generally much rounder looking.
Close up of a sparrowhawk
Close up of a kestrel
When identifying whilst flying, the flight pattern can be an excellent way to identify. Sparrowhawks tend to typically do five or six wing flaps followed by a short glide, and this pattern is repeated as they soar across the sky.
Sparrowhawks are also unable to hover like kestrels have the impressive and characteristic ability to do.
The sparrowhawk is suited and adapted for hunting birds in confined spaces, like gardens and dense woodland. In gardens, they've been recorded hunting 120 different species of mainly small birds, but larger birds such as pigeons are often predated on.
Sparrowhawks often fly low to the ground to surprise their prey with these attacks.
Kestrels mainly hunt for small mammals like voles, shrews and mice. In fact these generally make up around three-quarters of their overall diet. When small mammals are less abundant, small birds can make up more of their diet.
Both the average lifespan for a kestrel and sparrowhawk is around four years but have both been recorded at ages over 16 years.
Both kestrels and sparrowhawks are generally relatively silent birds and become more vocal during the breeding season.
Kestrels emit a piercing 'kee-kee-kee' call, which is mainly heard at nesting sites.
Sparrowhawks produce a call that is like a rapid cackling or chattering, similar to 'kewkewkewkew'.
Common Kestrel Call
Simon Elliott, XC590630. Accessible at www.xeno-canto.org/590630.
Simon Elliott, XC589041. Accessible at www.xeno-canto.org/589041.
Male kestrels have grey heads and tails and dark black bands at the end of their tails. The outer half of their upper wings are dark, with the rest of the wing and back a chestnut colour with dark spotting. The underparts are mostly pale and also have spotting, generally on the breast and on the underwing coverts.
Females are similar to males, although they lack the grey head and tail. Their plumages also tend to be more uniform and have heavier spotting. The tails also lack the black band and instead have many narrow bands.
Juveniles are extremely similar to females but have lighter feet, legs and cere.
Male sparrowhawks have slate-grey or bluish backs and wings and orangish bars on their breasts. Females have primarily brownish wings and greyish backs, with brown bars underneath.
Juvenile and young sparrowhawks are very similar to females, however, their breasts have more of a brown chevron pattern, instead of the horizontal bars.
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