The Sparrowhawk (Accipiter nisus) is a fierce hunter of the UK's woodlands, forests, gardens, and parks.
Their name strikes fear into the hearts of many garden bird lovers, but these pint-sized hunters are a vital part of the ecosystem, and studies have shown that they have little impact on songbird populations. But just how big are Sparrowhawks?
Sparrowhawks are small birds of prey. The largest have wingspans approaching 80 centimeters and weigh up to 350 g. They have short, broad wings but long wide tails used as rudders to maneuver while chasing down birds. They also have large feet with impressive talons for dispatching their prey.
Female raptors are usually larger than their male counterparts, and this trait is typified by the Sparrowhawk. Females are 16-25% larger than males, and the difference is easy to see when pairs perch near each other in the nesting season.
Their size difference also affects the prey items they target, with females taking birds like starlings and thrushes and males hunting smaller species like finches and tits.
There's a lot more to learn about the Sparrowhawk. Keep reading for more in-depth facts about their size.
Close up of a Sparrowhawk perched on a branch
Accipiters have a relatively short wingspan for a very good reason. These acrobatic birds fly through dense vegetation at high speeds where long wings would put them at a distinct disadvantage while pursuing their prey.
However, short wings don’t mean they aren’t quick. Sparrowhawks rely on rapid acceleration and a short burst of speed to catch their prey unawares.
The noticeable size difference between male and female Sparrowhawks is typical of birds of prey and particularly conspicuous in Accipiters. This phenomenon is known as sexual dimorphism, and it is even more notable when comparing the body mass of male and female Sparrowhawks.
Keep reading to learn how much Sparrowhawks weigh.
Female Sparrowhawks are significantly larger than males
Sparrowhawks are lighter than they look. Hollow bones and lightweight feathers keep their weight down and their speed up. There is a remarkable difference in size between male and female Sparrowhawks, which is most obvious when comparing their weights.
Female Sparrowhawks often weigh twice as much as males. In fact, the heaviest female Sparrowhawks are more than three times the weight of the lightest males. Being heavier means the females are less agile but lets them target larger prey like doves.
Male Sparrowhawks are sometimes up to half the weight of females
Sparrowhawks are small raptors, a fact well demonstrated when we compare them with our own size. Larger Sparrowhawks are about as long as a human forearm and have a wingspan of about an arm’s length.
Sparrowhawks generally hunt small to medium-sized birds, although large hen birds can take prey up to the size of a Wood Pigeon. Males generally hunt smaller birds like finches, while the larger females target birds like starlings and blackbirds.
Most birds of prey cannot carry animals of more than approximately half their own weight for any real distance. Sparrowhawks bring birds back to the nest when feeding their chicks, so they certainly can carry whole prey items.
The adult birds usually take their prey to a plucking post, where they remove the feathers before delivering the food to the nest. The plucking post is often located up-slope from the nest to make lifting the prey easier.
In other cases, Sparrowhawks will pluck and feed on birds where they catch them. In fact, a patch of plucked feathers is often all that is left behind to show where a Sparrowhawk killed its prey.
Scenes like this can be a good indication of a nearby nest, but you might find this evidence in parks and even your own garden.
Female Sparrowhawk hunting on the edge of a forest
We tend to think of hawks as large birds, but many people would be surprised at just how compact sparrowhawks are. However, their small size belies great ferocity, and these raptors often kill prey larger than themselves.
Sparrowhawks are perfectly evolved for hunting songbirds, and there is little competition for this abundant but challenging prey. Their compact size is a compromise between energy efficiency, agility, and power.
Sparrowhawks have surprisingly long legs and large feet. Their long legs give them a quick burst of speed as they launch themselves off a perch to begin their pursuit. Long toes effectively ‘widen the net’ to increase their chance of latching onto their prey.
Sparrowhawks have long tails that they use to control their direction and speed in flight. These acrobatic birds fly very low to the ground and use any available cover to remain hidden and strike with the element of surprise.
Their tails act as both brake and rudder to avoid collisions and out-maneuver their prey. Such agility is vital for squeezing through tight spaces between branches and making rapid twists and turns.
Male Sparrowhawk preparing to launch an attack on unsuspecting prey
Male Sparrowhawks are comparable in size to Turtle Doves, while females are closer to the size of a Stock Dove. They are one of the smaller birds of prey in the United Kingdom, similar in size to the Kestrel, Hobby, and Barn owl.
Sparrowhawks are not likely to be confused with other raptors in the UK. They are similar in appearance to the Goshawk (Accipiter gentilis), although much smaller.
Elsewhere, 45 species in the Accipiter genus occur on every continent except Antarctica, and the Sparrowhawk is fairly typical among them.
Most accipiters are small to medium-sized birds of prey that live and hunt in similar ways to the Sparrowhawk. The smallest is the Little Sparrowhawk (A. minullus) of Africa which has a wingspan of 39-52 cm and a mass of just 75 to 104 g.
Close up of a Eurasian Sparrowhawk in flight
Sparrowhawks are generally longer but lighter than pigeons, although the comparison is a useful one. Large female Sparrowhawks are near the size of smaller rock doves.
Sparrowhawks are far too small to pick up a cat. In fact, a cat is more of a threat to a Sparrowhawk than the other way around, so these birds tend to steer well clear of house cats.
Dog owners need not worry about Sparrowhawks. These birds are not capable of carrying off a dog. Sparrowhawks are specialist hunters of other birds. They rarely hunt mammals - even much smaller types like mice and voles.
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