pixabay Lizenz Lolame (https://pixabay.com/de/photos/sperber-eurasischer-sperber-vogel-6315901/)

Eurasian sparrowhawk

Description

Females are just larger than a kestrel, with a body length of 35-41 cm and a wingspan of 67 to 80 cm, and are close in size to small goshawk males. Sparrowhawk males are much smaller, with a body length of 29-34 cm and a wingspan of 58 to 65 cm. The wings are relatively short, broad, and rounded at their tips, and the tail feathers are relatively long. These characteristics do not allow for extreme flight speeds, but do enable high maneuverability in confined spaces. Legs and toes show distinct adaptations for hunting small and fast songbirds. The legs are comparatively long and very thin. The middle toe is very long and can be used to grasp objects, while a protuberance on the underside of the toe means that the digit can be closed without leaving a gap, and so can still hold individual feathers. The claws are long and very pointed.

Sparrowhawks show a very distinct sexual dimorphism with regard to colouration. Coloured (adult) male sparrowhawks are gray-blue on the upperparts. The underparts are white and finely barred ("sparred"). This banding is orange-red on the rump to a degree that varies individually in width and extent. Some males are almost solid orange on the underparts of the rump, in other birds the transverse banding is distinctly orange only on the flanks and brown on the rest of the rump. The neck shows fine vertical strokes that vary similarly to the rump pattern; in extreme cases, the neck is also solid red-orange. Females are less colourful than males. They are slate gray-brown on the upperparts, and the underparts banding may also be orange to high proportions on the flanks; however, this orange pattern is only exceptionally as extensive as in males.
Juveniles are brownish on the upperparts until the first molt, all coverts have light brown-beige edges. The underparts are white and barred that looks broader and often teardrop- or heart-shaped.

The large plumage has distinct barring on a white to beige-brown ground in all dresses, and on a yellowish ground in young birds. The legs are yellow, as is the ceroma of the beak. The iris is pale yellow in young birds, dark yellow in adult females, and mostly orange in males. The beak is black, blue-gray at the base.

Sexual dimorphism in terms of body size and weight is extreme in this species. The difference is so great that there is no overlap between the sexes in terms of body measurements. 

Possibilities of confusion exist in Central Europe primarily with the goshawk. In perching birds the distinction is usually easy, goshawks are much larger and stronger, this is especially noticeable when looking at the legs and head. Goshawks never show orange on the breast and belly and have a distinct whitish over-eye stripe, which is only hinted at in sparrowhawks. Sparrowhawk eyes are proportionally much larger and thus more conspicuous than in the goshawk.

It is more difficult to distinguish flying birds. The body proportions of sparrowhawks and goshawks are very similar, so at greater distances it is often impossible to distinguish gliding or soaring birds in particular. In reasonably good visibility conditions, however, the much more massive body and proportionally longer wings of the goshawk are recognizable even in flight. In actively flying individuals, the frequency of wing beats also often allows species identification: this is about twice as high in sparrowhawks as in goshawks.

Habitat

The occurrence of the species is limited in most of its range to the north as well as to the south by the distribution of these coniferous forests. Only in Central and Western Europe, as well as in the Western Mediterranean, where other small representatives of the genus Accipiter inhabiting deciduous forests are absent, it also inhabits deciduous forests of the temperate zone, as well as the Mediterranean hardwood forests. In recent decades, this raptor species also shows a strong tendency towards urbanization and now inhabits parks, cemeteries and similar green spaces in many cities in Europe.


The text is a translation of an excerpt from Wikipedia (https://de.wikipedia.org/wiki/Sperber_(Art)). On wikipedia the text is available under a „Creative Commons Attribution/Share Alike“licence. Status: 17 December 2021