Northern Goshawk

The Northern Goshawk is a massive bird of prey with a distinct forest silhouette — short broad rounded wings and a long tail are not for aesthetics, but an adaptation for maneuverable flight among branches. Its flight silhouette resembles a sparrowhawk, but the scale is completely different: an adult goshawk matches a buzzard in size.

Body length is 49–63 cm, wingspan 100–135 cm. Sexual dimorphism is reversed — as in most birds of prey, but particularly pronounced in the goshawk. A male weighs 600–900 g, while a female weighs 900–1500 g — which is on average about 50% more. Dimorphism is also visible in dimensions: the female is larger and more massive, the male is sleeker. In the field, the difference is distinct enough that a male goshawk can be mistaken for a large female sparrowhawk.

Adult bird coloration: back and wing coverts are blue-gray to ash-gray, underside white or cream with dense, horizontal dark gray bars covering the chest, belly, and underwing coverts. The most characteristic field feature is the distinct white eyebrow above the eye, contrasting with the dark crown. Eyes change color with age: yellow in juveniles, orange in adults, and red in very old individuals. Strong curved beak with a yellow cere, massive yellow legs with long black talons.

Juveniles (1st calendar year) look completely different: brown back with rusty feather edges, cream or yellowish underside with vertical (not horizontal!) dark drop-shaped spots. This is a key feature differentiating them from adults and is diagnostic in the field — the pattern changes from vertical to horizontal only after the first full molt in the 2nd year of life. The white eyebrow is already visible in juveniles but contrasts less with the brown crown.

• Short broad rounded wings + long tail — adaptation to maneuverable forest flight
• Distinct white eyebrow above the eye — key field feature of the adult
• Underside with dense horizontal bars in adults, vertical spots in juveniles
• Eyes change color with age — yellow (juvenile) → orange (adult) → red (old)
• Reversed dimorphism — female is approx. 50% heavier than the male
• Flight — several strong wing beats + short gliding phase
• Massive yellow legs with long black talons — for gripping prey the size of a pigeon

The goshawk is a forest species par excellence — specialized in maneuverable flight among branches. Classic habitats are dense deciduous and mixed forests with an admixture of old conifers, but since the 1990s, the bird has increasingly inhabited urban parks and larger wooded areas within cities.

Classic habitats in Poland include: dense deciduous forests (beech, oak), mixed forests with spruce and pine, coniferous forests with deciduous admixture, forest complexes of lake districts, and river valleys with riparian forests and old alders. Key habitat requirements are: tall old trees suitable for nesting (usually spruce, pine, oak) and access to open or semi-open spaces (clearings, young stands, meadows, fields) where the goshawk can hunt.

Synanthropization of the goshawk in Poland is a phenomenon of the last thirty years. The first documented urban nests in PL date back to around 1995 — Warsaw, Łazienki Park. Today, the species regularly nests in large cities: Warsaw (approx. 30–40 pairs, most dense in Bielański Forest, Kabaty, and Łazienki), Kraków (Wolski Forest, Decius Park), Wrocław (Szczytnicki Park, Osobowicki Forest), Poznań (Citadel, suburban forests). Favorable factors include: cessation of persecution after the introduction of protection, abundance of urban pigeons as a constant food base, lack of competition from larger predators in cities, and climate warming shortening the period of food unavailability.

Geographical range in Poland covers the entire country — from the Baltic to the Carpathians. The highest densities are recorded in areas with large forest complexes and low degree of urbanization (Masurian Lake District, Tuchola Forest, Białowieża Forest, Roztocze, Beskids). The species is resident in Poland — pairs stick to their territory year-round, although juveniles disperse 50–300 km from the hatching site after leaving the nest. In winter, individuals from Scandinavia and northern Russia arrive in PL, temporarily increasing local densities.

• Classic habitat — dense deciduous and mixed forests with old trees
• Required nesting trees — spruce, pine, oak, beech; minimum 12 m height
• Access to open spaces — clearings, young stands, fields, meadows
• Synanthropization since the 90s — first urban nests in PL approx. 1995 (Warsaw)
• Large cities with populations — Warsaw, Kraków, Wrocław, Poznań
• Resident species — pairs hold territory year-round
• Winter influx of individuals from Scandinavia and Russia
• Highest densities — lake districts, Tuchola Forest, Roztocze, Beskids

The goshawk is a specialized bird hunter — with an emphasis on medium to large-sized prey. Unlike the sparrowhawk, which targets small songbirds, the goshawk takes targets such as pigeons, jays, and pheasants. The hunting technique is based on surprise and maneuverability, not endurance.

Diet composition in natural conditions: medium and large birds 60–80% of biomass — wood pigeons and stock doves, jays, jackdaws, magpies, partridges, pheasants, mallards, herons, woodcocks. Mammals 15–30% — red squirrels (favorite prey in coniferous forests), rats, small hares, young foxes, and martens. The rest are small songbirds and occasionally reptiles. In the city, proportions change radically: the urban pigeon (feral rock dove) constitutes up to 90% of the diet in some urban populations, supplemented by jackdaws, rooks, and park squirrels.

Hunting technique relies on ambush and short maneuverable attacks. The goshawk spends most of its time on a perch — a low, well-hidden branch at the edge of a forest or clearing. When prey appears in range, the bird launches into a fast low flight between trees, using short broad wings and a long tail for sudden turns. The attack is short — the chase usually lasts 5–15 seconds. Prey is caught with talons and killed by pressure; the goshawk does not use its beak to kill the prey, but only to pluck and divide it into pieces in a safe place (called plucking sites or 'oskubywiska').

• Ambush attack — perch at forest edge, short maneuverable flight
• Medium and large prey — pigeon, jay, partridge, pheasant, duck
• Squirrel as a favorite prey in coniferous forests
• Short chase — typically 5–15 seconds, gives up over longer distances
• Plucking sites — permanent places for prey consumption under trees
• In cities — urban pigeon up to 90% of diet
• Hunting mainly at dawn and dusk — peak activity of prey

The goshawk is a monogamous species with high loyalty to both partner and nest. Pairs use the same nest for many consecutive seasons (records >30 years), and males and females stay together until the death of one partner. There is a single brood — one per season — meaning that the breeding success of a given year determines the pair's offspring production.

Courtship displays begin in February–March. The pair performs joint flights near the nest — soaring with undulating flight, mutual food passing in flight, and demonstrative flights with exposed white undertail coverts. The male provides the female with food during the pre-breeding period, which serves as a test of the partner's condition and prepares the female for the energy-intensive incubation.

The nest is built on tall old trees — most often spruce, pine, or oak, at a height of 12–25 m, in the main fork of the trunk or on a thick branch near the trunk. The construction is a platform of twigs 70–120 cm in diameter, lined with green coniferous twigs, which are replaced by the female throughout the breeding period — the resins in the twigs have an effect of repelling external parasites. A pair usually has 1–3 alternative nests within the territory and rotates between them in subsequent years.

The brood consists of 2–4 eggs (rarely 5) laid at 2–3 day intervals in the second half of April. Incubation lasts 35–38 days and is conducted almost exclusively by the female; the male brings food. Chicks hatch asynchronously and for the first 3 weeks are closely guarded by the female, who does not leave the nest. Fledging from the nest occurs on the 36–42 day of life, but the young remain near the nest and are fed by parents for another 4–6 weeks — full independence by the end of September. Sexual maturity: 2–3 years for females, 1–2 years for males.

Goshawks are rarely seen in the field — they are a secretive species that hunts by ambush. It is easier to find signs of its presence: pellets, prey feathers, plucking sites, characteristic calls during the breeding season, and changes in the behavior of local birds.

Pellets of the goshawk are large (5–8 cm long, 2–3 cm in diameter), gray or light gray, containing mostly feathers and small bones of prey. Unlike owl pellets, which are compact and regular, diurnal bird of prey pellets are looser and less compact — the beak and stomach acids break down most bones, so mainly feathers stuck in a ball remain. Most often found under the nest, under favorite perches, and near consumption sites.

Plucking sites (oskubywiska) are permanent places where the goshawk plucks and consumes caught prey — most often a wide low trunk, stump, thick branch lying on the ground, or sometimes a flat stone in a clearing. Under such a spot lies a characteristic scattered pile of feathers, from which the prey species can be identified (pigeon, jay, partridge). Feathers are plucked with the shafts intact — this is a diagnostic difference from a fox or marten, which leave feathers bitten off with distinct teeth marks on the shaft. Plucking sites are used repeatedly and are often located near the nest.

Tracks of the goshawk in snow or mud are characteristic of a large bird of prey: four toes arranged in a K-shape (three forward, one backward), single track length 6–9 cm, width 7–10 cm. They are rarely encountered, usually in winter in the snow under perches or in places where the goshawk approached prey on the ground. The voice is heard mainly during the breeding season (February–June) — a characteristic "kjak-kjak-kjak-kjak" of the female near the nest when disturbed, and a higher-pitched "gi-gi-gi-gi" from the male.

• Pellets — gray, 5–8 cm, mainly feathers; found under nests and perches
• Plucking sites — a pile of prey feathers under a permanent consumption spot
• Feathers plucked with shafts — diagnostically different from mammalian predators
• Tracks — 6–9 cm, K-shaped arrangement, mostly in winter snow
• Voice — "kjak-kjak-kjak" (female), "gi-gi-gi" (male) during breeding season
• Feathers replaced in nest — fresh coniferous twigs throughout the breeding period
• Changes in local bird behavior — jay alarms, pigeons fleeing in groups

The goshawk is highly territorial and strictly bound to its partner. A pair occupies an extensive territory — from 1,000 to 10,000 ha depending on habitat quality — which they actively defend against other goshawks and larger predators near the nest.

Territory size varies significantly: in optimal habitats (dense forests with a large food base), densities reach one pair per 1,000–3,000 ha; in poorer habitats — one pair per 5,000–10,000 ha. In cities, territories are much smaller due to the abundance of food (urban pigeons) — in Warsaw, pairs have been recorded nesting less than 2 km from each other in the Bielański Forest. Territory boundaries are defended mainly during the breeding season (February–June); outside the season, the pair tolerates the presence of other goshawks in peripheral parts of the range.

Courtship displays begin as early as February, when both birds perform high flights over the forest — shallow undulating flight, with wavy rising and falling, sometimes displaying white undertail coverts as a signal. The male also performs single wave flights with loud calls, marking territory boundaries for rivals. Partner loyalty is a hallmark of the species — pairs stay together for many seasons, and separation practically occurs only as a result of the death of one bird. A partner who has lost a mate usually finds a new one within 1–2 seasons, if they survive the first winter alone.

Daily activity has two peaks: morning (from dawn to 2–3 hours after sunrise) and afternoon (2–3 hours before sunset). During midday hours, the goshawk usually rests on a branch in a dense stand, digesting and cleaning its plumage. In winter, activity is more uniform and spread across the entire short day. Reaction to humans is usually balanced — the bird flees when approached, but near the nest, the female may actively attack an intruder — there are documented cases of talons striking the heads of foresters and photographers attempting to climb the nest tree.

In Poland, the goshawk is subject to strict protection with zonal nest protection and is among the species whose population status is stabilizing or improving. However, this does not mean there are no threats — the main ones are collisions with infrastructure, poaching at pigeon lofts, and loss of old nest trees in commercial forests.

Protection status in Poland: strict protection based on the Regulation of the Minister of Environment of 16 December 2016 on species protection, with additional zonal nest protection (200 m year-round, 500 m in season I–VIII). In the EU, it is covered by the Birds Directive 2009/147/EC, and globally IUCN classifies it as LC (Least Concern). Polish population: 6–8 thousand breeding pairs according to PTOP and GIOŚ, with a stable or slightly increasing trend nationwide, and a distinct increase in urban areas since the 90s.

Main threats: (1) collisions with glass and transparent acoustic screens by highways — during prey pursuit, the goshawk does not recognize transparent barriers; (2) collisions with power lines, particularly in juveniles; (3) poaching at pigeon lofts — there are documented cases of illegal shooting, poisoning (carbofuran, mevinphos), and Larsen-like traps; (4) loss of nest trees — cutting down old trees in commercial forests despite zonal protection (cases of unregistered nests); (5) secondary poisoning with anticoagulant rodenticides through feeding on rats.

The goshawk as a bioindicator of environmental quality: as a species at the top of the food pyramid, it accumulates pollutants from the entire food chain. Polish studies (including PTOP, IBL) have shown elevated concentrations of lead (from lead ammunition in carrion and urban dust), mercury, and polychlorinated biphenyls in urban goshawks. A decline in the goshawk population in a given region is today understood as a signal of overall environmental degradation, not as a result of direct persecution as was the case before the introduction of protection in the 1970s.

• Strict protection + zonal nest protection (200 m year-round, 500 m in season)
• EU Birds Directive, IUCN: LC (Least Concern)
• PL population — 6–8 thousand pairs; stable or slightly increasing trend
• Collisions with glass and screens — main urban threat
• Collisions with power lines — mostly juveniles
• Poaching near pigeon lofts — shooting, poisoning, traps
• Loss of nest trees — logging despite protection zones
• Bioindicator — accumulates lead, mercury, PCBs from the food chain

The goshawk is a species surrounded by many myths — both among pigeon breeders and forest walkers. The truth is usually more interesting than the legend, and several common beliefs are simply incorrect.

• MYTH The goshawk and sparrowhawk are the male and female of the same species.

  FACT Untrue — they are two different species of the genus Accipiter. The Northern Goshawk is Accipiter gentilis (49–63 cm, 600–1500 g), while the Sparrowhawk is Accipiter nisus (28–38 cm, 110–340 g) — see separate sparrowhawk profile. The myth originated from reversed dimorphism in both species: a female sparrowhawk is larger than a male sparrowhawk, and a male goshawk is smaller than a female goshawk — which leads to mistaking a female sparrowhawk for a male goshawk. However, they differ diagnostically in size (female sparrowhawk approx. 340 g vs male goshawk approx. 800 g), wing-to-tail proportions, and dietary preferences.

• MYTH The goshawk wipes out all birds in the area.

  FACT A myth among pigeon breeders. A pair of goshawks takes about 400–600 prey items annually, which within a territory of 1,000–10,000 ha is local regulation, not elimination of prey populations. In a natural ecosystem, predators at the top of the food pyramid keep prey populations in balance by eliminating weaker and sick individuals. Local drops in pigeon or jay numbers around an active goshawk nest are temporary and compensated by immigration from neighboring areas. The absence of goshawks in a given ecosystem is more often a sign of its degradation than the presence of this species.

• MYTH The goshawk snatches small dogs and cats.

  FACT An urban myth, extremely rarely true. A female goshawk (up to 1.5 kg) could theoretically lift prey weighing up to 1 kg, but typically mammal attacks are limited to squirrels and rats. Documented attacks on domestic cats in Poland are single cases per year, mostly involving small kittens or sick individuals. Attacking a healthy adult cat is risky for a goshawk — a cat has weapons (claws, teeth) and can injure the bird. An attack on a small dog (up to 3 kg) is practically unheard of — the dog resists and is often under human supervision, which deters the goshawk. Fear for a pet walked in an urban park in the presence of a goshawk is statistically unjustified.

• MYTH A goshawk in the city is an unbelievable sight.

  FACT Untrue — since the 90s. The first documented urban goshawk nests in Poland date back to around 1995 in Warsaw's Łazienki Park. Today, in Warsaw alone, about 30–40 pairs live — most densely in the Bielański Forest, Kabaty, Royal Łazienki, and Powązki Cemetery. Similar urban populations are maintained in Kraków, Wrocław, Poznań, and Łódź. Favorable factors: abundance of urban pigeons as a constant food base, lack of competition from larger predators, cessation of persecution after the introduction of protection. Meeting a goshawk in a large urban park is possible every day of the year today.

• MYTH White goshawks do not exist.

  FACT Untrue. In populations from Scandinavia and northern Russia, a pale (leucistic) form of the goshawk is documented — the nominate subspecies A. g. atricapillus and color mutations within A. g. gentilis. Pale individuals have a very light gray or almost white back and significantly reduced underside barring. In Poland, such birds are observed very rarely, mainly in winter in the north of the country, as arrivals from Scandinavia. The pale form is not albinotic (eyes are normal orange), but leucistic — resulting from a mutation affecting melanin distribution.

• MYTH A goshawk can be kept like a falcon.

  FACT Only with a falconry license and from a legal breeder. Falconry in Poland is regulated by the Hunting Law and the Nature Conservation Act. To keep a goshawk as a hunting bird, one must: (1) pass a falconry exam at the Polish Falconers Club, (2) obtain a GDOŚ permit, (3) acquire the bird exclusively from a legal breeder — with a ring and CITES documents, never from the wild. Taking a goshawk from a wild nest is a crime prosecuted ex officio. Historically, the goshawk was one of the primary falconry birds in Poland — used for hunting hares, partridges, and pheasants — but today it is a niche activity, strictly regulated, available only to trained falconers.