Tuesday, 17 June 2014

Week 53: Sparrowhawk ('Accipiter nisus')

The Sparrowhawk was @SpeciesofUK from 10th to 16th March, 2014.

The UK's sparrowhawk is also known the 'northern sparrowhawk' or 'Eurasian sparrowhawk' to distinguish it from other sparrowhawks.[1]

[Flickr Creative Commons © Philippe Garcelon]

It is a small raptor with short rounded wings and long legs.

The sparrowhawk is a member of the Accipiter genus.

Accipiter is the genus which contains all the hawks commonly known as sparrowhawks and goshawks.[2]

The birds of the Accipiter genus are sometimes described as the 'true' hawks. This is because the common term ‘hawk' can be loosely applied to many other diurnal raptors.[3]
Sparrowhawk - a 'true' Hawk
[Flickr Creative Commons © Sergey Yeliseev]

Aside from the Eurasian sparrowhawk, the only other Accipiter species found in the UK is the northern goshawk, Accipiter gentilis. The goshawk is much larger than the sparrowhawk.[4]

There are 6 subspecies of Eurasian sparrowhawk in all. The UK subspecies is the same as is found in most of Europe. There are Corsican and Canary Island subspecies too.[5]

The sparrowhawk is a relatively small raptor.

The sparrowhawk has short, rounded wings, long legs and a very strongly hooked bill.[6]

[Flickr Creative Commons © Jean-Jacques Boujot]

The male sparrowhawk has a small pale line above the eye and reddish barring on underparts.[7]

Male Sparrowhawk
[Flickr Creative Commons © Steve Harris]

Female sparrowhawks are much larger. They are darker above and have grey barring on white underparts.[8]

Female Sparrowhawk
[Flickr Creative Commons © mcamcamca]

Juvenile sparrowhawks look like the females but have broader barring and browner upperparts.[9]

Juvenile Sparrowhawk
[Flickr Creative Commons © Phil]

People can be surprised by how small sparrowhawks are. Here is one being chased by a crow which gives a sense of scale.

Sparrowhawk and Hooded Crow
[Flickr Creative Commons © Sergey Yeliseev]

Sparrowhawks are the most likely bird of prey for you to see in your garden, because they are able to chase small birds in an enclosed space. The RSPB say they get more calls about identifying sparrowhawks than any other bird.[10]

Sparrowhawks have a distinctive hunting style.

Sparrowhawks hunt by flying low, along hedgerows, threading through woods, dashing upon unsuspecting birds.[11]

Sparrowhawk Flying Low
[Flickr Creative Commons © Hiyashi Haka]

Sparrowhawks pick out one bird from a flock and ignore the mobbing from other birds. They're extremely persistent.[12]

Sparrowhawk with Starling
[Flickr Creative Commons © Radovan Vรกclav]

In full pursuit sparrowhawks chase prey blindly and will follow them into undergrowth or crash into a hedge. They've even crashed to death against windows in chase.[13]

Here is a great clip from the BBC's Life of Birds showing a sparrowhawk hunting in forest.

Sparrowhawks eat their quarry on the ground or on a stump, standing with both feet on the victim and drooping their wings to form a tent.[14]

Sparrowhawk with Dunnock
[Flickr Creative Commons © Dave Curtis]

A huge variety of species are taken by sparrowhawks, primarily small birds like finches, sparrows and tits, but also pigeons, game birds and small mammals.[15]

Because of their large size, female sparrowhawks take larger prey than males and hunt in more open areas.[16]

Female Sparrowhawk with Lapwing
[Flickr Creative Commons © Billy Lindblom]

Several sparrowhawks can share the same hunting territory, if they habitually hunt at different times of the day.[17]
The sparrowhawk breeding season lasts from April to August.[18]

This exact date of sparrowhawk breeding is timed locally to coincide with the maximum availability of hatchlings of prey species.[19]

Breeding pairs are often of a similar age. If they breed successfully, they will often stay together from year to year and return to the same nesting area. They build a new nest each year.[20]

Sparrowhawks construct a platform of sticks for a nest on a fork or branch of a tree, usually in woodland bordering a clearing.[21]

Sparrowhawk Nest
[Flickr Creative Commons © Nottsexminer]

Sparrowhawks lay three to six eggs which hatch after thirty-two to thirty-four days. The female broods the chicks. At first it’s the male that supplies the food. Later, both parents do.[22]

Sparrowhawk Chicks
[Flickr Creative Commons © Simon Willison]
Sparrowhawk chicks fledge one month after hatching. They're fed by the parents for another three to four weeks before becoming fully independent.[23]

Sparrowhawk Fledgling
[Flickr Creative Commons © Nottsexminer]

In winter sparrowhawks disperse to a wider variety of habitats, even areas with few trees and from mountains to the coast.[24]

Sparrowhawks live for two to four years. Amazingly, the oldest recorded was a twenty year old individual found in Denmark.[25]

Sparrowhawk numbers have been on the rise.

The sparrowhawk suffered a catastrophic decline in the 1950s and 60s. Organochlorine pesticides decimated sparrowhawks due to their rapid build-up in the food chain.[26]

Sparrowhawks also used to suffer from direct human persecution because they were thought to damage game bird and racing pigeon populations.[27]

The banning of damaging pesticides and changing attitudes from the 1970s onwards means the global sparrowhawk population has rebounded to a healthy 1.5 million.[28]

[Flickr Creative Commons © Muzaffar Bukhari]

Sparrowhawks are now one of the commonest birds of prey in the UK and indeed the whole of Europe.[29]

[Flickr Creative Commons © Sergey Yeliseev]

Strange but true…

In Tunisia, Georgia and Turkey, migrant sparrowhawks are captured and used to hunt quail. Traditionally, they were released at the end of the hunting season.[30]

[1] http://en.m.wikipedia.org/wiki/Eurasian_Sparrowhawk
[2] http://en.m.wikipedia.org/wiki/Accipiter
[3] http://en.m.wikipedia.org/wiki/Hawk
[4] http://en.m.wikipedia.org/wiki/List_of_birds_of_Great_Britain
[18] http://www.arkive.org/eurasian-sparrowhawk/accipiter-nisus/
[19] http://www.arkive.org/eurasian-sparrowhawk/accipiter-nisus/
[20] http://animaldiversity.ummz.umich.edu/accounts/Accipiter_nisus/
[21] http://www.arkive.org/eurasian-sparrowhawk/accipiter-nisus/
[22] http://www.arkive.org/eurasian-sparrowhawk/accipiter-nisus/
[23] http://www.arkive.org/eurasian-sparrowhawk/accipiter-nisus/
[24] http://www.arkive.org/eurasian-sparrowhawk/accipiter-nisus/
[25] http://animaldiversity.ummz.umich.edu/accounts/Accipiter_nisus/
[26] http://www.arkive.org/eurasian-sparrowhawk/accipiter-nisus/
[27] http://en.m.wikipedia.org/wiki/Eurasian_Sparrowhawk
[28] http://www.arkive.org/eurasian-sparrowhawk/accipiter-nisus/
[29] http://en.m.wikipedia.org/wiki/Eurasian_Sparrowhawk
[30] http://en.m.wikipedia.org/wiki/Eurasian_Sparrowhawk

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