The sparrowhawk (Accipiter nisus) is a small, agile bird of prey belonging to the Accipitridae family of hawks and eagles. This raptor is widely distributed across the temperate and subtropical regions of the Old World, including Europe and Asia. It is an accomplished hunter specializing in pursuing other birds, often navigating dense environments with speed and precision.
Physical Traits and Sexual Dimorphism
The physical structure of the sparrowhawk features short, rounded wings and a long tail. These proportions allow it to maneuver swiftly through cluttered habitats like dense woodland and hedgerows. This species exhibits pronounced reversed sexual dimorphism, where the female is noticeably larger than the male, a characteristic most evident in bird-hunting raptors.
Females can be up to 25% larger in length and weigh almost twice as much as males (185 to 342 grams compared to the male’s 110 to 196 grams). Plumage also differs significantly between the sexes. The adult male has slate-grey or bluish upperparts with finely orange-barred underparts. In contrast, the female has dark brown or grayish-brown upperparts and is coarsely barred with brown on her underside.
Preferred Habitats and Range
The sparrowhawk’s range extends across Eurasia, from the Atlantic coast to the eastern limits of Siberia and Japan; northern populations migrate south for the winter. It generally favors areas that provide ample cover for hunting and nesting. It thrives in woodland edges, dense copses, and mixed or coniferous forests.
Their requirement for cover has allowed them to successfully colonize human-dominated landscapes. Sparrowhawks are increasingly found in suburban parks, large gardens, and even city centers, provided there are sufficient trees for nesting and perching. This ability to exist near human settlements makes them a common sight for many people across their distribution.
Hunting Style and Diet
The sparrowhawk employs a hunting strategy based on ambush and surprise rather than high-altitude soaring and pursuit. It launches fast, low-level attacks, often using the cover of hedges, buildings, or woodland to conceal its approach. This element of surprise is necessary, as only about one in ten hunting attempts are successful.
The diet consists almost entirely of small and medium-sized birds, with over 120 prey species recorded across its range. The marked size difference between the sexes enables them to target different prey, reducing competition for food. Smaller males primarily capture tits, finches, and sparrows, typically taking prey up to 40 grams. The larger females are strong enough to take heavier birds, such as thrushes, starlings, or wood pigeons weighing up to 500 grams.
Conservation Status and Interaction with People
The sparrowhawk experienced a substantial population decline in the mid-20th century, primarily due to the widespread use of organochlorine pesticides like DDT and dieldrin. These chemicals accumulated through the food chain, causing reproductive issues such as eggshell thinning and reduced hatching success.
Following the regulation and banning of these persistent chemicals in the 1960s and 1970s, sparrowhawk populations made a recovery. The species is now common and widely protected, holding a global conservation status of Least Concern. Interaction with people is most frequent in garden settings, where the birds sometimes prey on songbirds at feeding stations. Scientific studies indicate that sparrowhawk predation does not cause a long-term decline in songbird breeding populations.