Basic Principles
An encounter with either of Britain’s two Accipiter hawk species is always an exciting moment. However, although Eurasian Sparrowhawk and Northern Goshawk are often straightforward to identify on a good view, a brief or distant sighting can be deceptive, particularly for those unfamiliar with the larger species. As a result, Eurasian Sparrowhawk is frequently misidentified as Northern Goshawk in Britain.
Eurasian Sparrowhawk
This feisty small Accipiter is widespread in the Palearctic, its range stretching from the Canary Islands and Madeira in the west to Kamchatka in the Russian Far East. It occurs throughout Britain and Ireland and is, along with Common Buzzard and Common Kestrel, one of our most numerous raptors. It is largely resident, although there is some evidence of limited migration from the Continent.
Encounters are typically brief, and it is most frequently seen hunting low and fast along woodland edges and roadside hedges, but occasionally also in gardens. This is the ultimate ambush predator of small birds, relying on surprise and the speed of its pursuit. It will sometimes even chase small birds on foot. In early spring, however, Eurasian Sparrowhawks can be seen displaying high over their breeding woodlands, allowing a more extended view.
This is a small raptor, most similar in size to Common Kestrel, though – as in all birds of prey – the females are larger than the males. The Accipiter shape is very distinctive, with short and broad wings with a strongly rounded wing-tip – ideal for rapid manoeuvring in confined spaces. When not hunting, its flight lacks the aerial mastery of falcons and appears a little weak – a very characteristic ‘flap, flap, glide’.
Apart from the wing shape, typical components of Eurasian Sparrowhawk’s silhouette are a small head, long tail (longer than the breadth of the wings) which is rather narrow at the base and has quite ‘square’ corners. The main confusion risk lies with the larger female. Although not truly of Northern Goshawk size, they can sometimes appear rather large, particularly when displaying. At such times, the slow, ponderous wing beat and the expanded white undertail coverts can create the impression of a much bigger bird.
A normal Eurasian Sparrowhawk view reveals little plumage detail but, if seen well, the adult males are beautifully blue-grey above and delicately barred rustyorange below, with orange also on the cheeks. Adult females are drabber, brown-grey above and barred brown below. Juveniles are brown above with subtle dark bands across the upperwings in flight, and are marked with coarse brown transverse barring on the underparts.
Northern Goshawk
This species has an even larger range than Eurasian Sparrowhawk, occurring throughout the Holarctic. It is, however, a much rarer bird in Britain, with a population of just a few hundred pairs. It is unfortunately a heavily persecuted raptor and would otherwise certainly be more widespread.
This is a forest-dweller rather than a bird of open country, so casual encounters with hunting Northern Goshawks are inf requent. It is a species best sought on sunny, breezy days in late winter and early spring when birds are displaying over their breeding territories. Once the display period is over, they seem to melt away once more, remaining for much of their time beneath the woodland canopy. Northern Goshawk is resident here and is rarely sighted away from its breeding areas. Records of the species elsewhere, therefore, demand particular scrutiny.
This is a much larger species than Eurasian Sparrowhawk. The males have the same size wingspan as a Carrion Crow, while that of the females is similar to that of Common Buzzard. Judging size on a lone bird in the sky is difficult, however, and, as noted above, female Eurasian Sparrowhawks can appear disconcertingly large.
Northern Goshawks are best identified on structure. Compared with Eurasian Sparrowhawk, they are larger headed, longer necked and heavier bodied, while the wing structure differs in being longer, with a longer ‘arm’, a more pointed ‘hand’ and bulging secondaries forming a slight ‘S’ curve on the rear edge of the wing. There are differences in the tail, too, which appears slightly shorter (comparable to the wing breadth), broader based and has rather rounded corners. On a rare perched view, the tarsi are thick and powerful in contrast to the somewhat spindly legs of a Eurasian Sparrowhawk – a clear indication that goshawks take much larger and more powerful prey such as pigeons, corvids and squirrels, rather than small passerines.
This combination of larger size and heavier structure gives Northern Goshawk a stronger, steadier flight and a more powerful wing action than Eurasian Sparrowhawk. The species has an impressive presence in the air, causing mass flushes of Woodpigeons and Rooks. The display flight is particularly heavy and ponderous, with the heavy-bodied structure accentuated by strongly expanded white undertail coverts. While misidentification with Eurasian Sparrowhawk is an ever-present risk, another potential confusion species is Hen Harrier and, elsewhere in northernmost Europe, Gyr Falcon.
Both adult male and female Northern Goshawks are a cold, steely grey above, with grey barring below and a much stronger face pattern than Eurasian Sparrowhawk comprising solidly dark crown and ear coverts and a prominent white supercilium. Juveniles are a rich warm brown above with slightly stronger dark bands across the upperwings in flight. The most striking feature, however, is the underparts pattern, which comprises large vertically aligned drop-shaped streaks, very different indeed from the barred underparts of juvenile Eurasian Sparrowhawks.