Hunting behaviour As typical of the genus
Astur (as well as
Accipiter,
Tachyspiza and other distantly related forest-dwelling raptors of various lineages), the Eurasian goshawk has relatively short wings and a long tail which make it ideally adapted to engaging in brief but agile and twisting hunting flights through dense vegetation of wooded environments. This species is a powerful hunter, taking birds and mammals in a variety of woodland habitats, often utilizing a combination of speed and obstructing cover to ambush their victims. Goshawks often forage in adjoining habitat types, such as the edge of a forest and meadow. Hunting habitat can be variable, as in a comparison of habitats used in
England found that only 8% of landscapes used were woodlands whereas in
Sweden 73-76% of the habitat used was woodland, albeit normally within of an opening. The Eurasian goshawk is typically considered a perch-hunter. Hunting efforts are punctuated by a series of quick flights low to the ground, interspersed with brief periods of scanning for unsuspecting prey from elevated perches (short duration sit-and-wait predatory movements). These flights are meant to be inconspicuous, averaging about 83 seconds in males and 94 seconds in females, and prey pursuits may be abandoned if the victims become aware of the goshawk too quickly. More sporadically, Eurasian goshawks may watch for prey from a high soar or gliding flight above the canopy. One study in
Germany found an exceptional 80% of hunting efforts to be done from a high soar but the author admitted that he was probably biased by the conspicuousness of this method. In comparison, a study from
Great Britain found that 95% of hunting efforts were from perches. Eurasian goshawks rarely vary from their perch-hunting style that typifies the initial part of their hunt but seems to be able to show nearly endless variation to the concluding pursuit. Hunting goshawks seem to not only utilize thick vegetation to block them from view for their prey (as typical of
Astur and
Accipiter species) but, while hunting flying birds, they seem to be able to adjust their flight level so the prey is unable to see its hunter past their own tails. Anecdotal cases have been reported when goshawks have pursue domestic prey into barns and even houses. Prey pursuits may become rather prolonged depending upon the goshawk's determination and hunger, ranging up to 15 minutes while harrying a terrified, agile
squirrel or
hare, and occasional pair hunting may benefit goshawks going after agile prey. As is recorded in many accipitrids, hunting in pairs (or "
tandem hunting") normally consist of a breeding pair, with one bird flying conspicuously to distract the prey, while the other swoops in from behind to ambush the victim. The daily food requirements of a single goshawks are around and most kills can feed a goshawk for 1 to 3 days.
Prey spectrum Eurasian goshawks are usually opportunistic predators, as are most
birds of prey. The most important prey species are small to medium-sized
mammals and medium to large-sized birds found in forest, edge and scrub habitats. Primary prey selection varies considerably not just at the regional but also the individual level as the primary food species can be dramatically different in nests just a few kilometers apart. Prey selection also varies by season and a majority of dietary studies are conducted within the breeding season, leaving a possibility of bias for male-selected prey, whereas recent advanced in radio-tagging have allowed a broader picture of goshawks' fairly different winter diet (without needing to kill goshawks to examine their stomach contents). Birds are usually the primary prey in Europe, constituting 76.5% of the diet in 17 studies. Studies have shown that from several parts of the Eurasian continent from
Spain to the
Ural Mountains mammals contributed only about 9% of the breeding season diet. However, mammals may be slightly underrepresented in this data because of the little-studied presence of mammals as a food source in winter, particularly in the western and southern portions of Europe where the lack of snowfall can allow large numbers of
rabbits. Staple prey for Eurasian goshawks usually weighs between , with average prey weights per individual studies typically between . In the
Netherlands, male prey averaged whereas female prey averaged , thus a rough 45% difference. This is fairly different from
Vendsyssel,
Denmark, where mostly adult birds were caught except for thrushes and corvids, as in these two groups, the goshawks caught mostly fledglings.
Corvids Overall, one prey family that is known to be taken in nearly every part of the goshawk's range is the corvids, although they do not necessarily dominate the diet in all areas. Some 24 species have been reported in the diet of Eurasian and American goshawks. The second most commonly reported prey species in breeding season dietary studies from Europe is the
Eurasian jay (
Garrulus glandarius). These species were recorded in studies from northeastern
Poland and the
Apennines of
Italy (where the Eurasian jays made up a quarter of the food by number) as the main prey species by number. The conspicuously loud vocalizations, somewhat sluggish flight (when hunting adult or post-fledging individuals) and moderate size of these jays make them ideal for prey-gathering male goshawks. Another medium-sized corvid, the
Eurasian magpie (
Pica pica) is also amongst the most widely reported secondary prey species for goshawks there. Magpies, like large jays, are rather slow fliers and can be handily outpaced by a pursuing goshawk. Some authors claim that taking of large corvids is a rare behaviour, due to their intelligence and complex sociality which in turn impart formidable group defenses and mobbing capabilities. One estimation claimed this to be done by about 1–2% of adult goshawks during the breeding season (based largely on studies from Sweden and England), however, on the contrary many goshawks do routinely hunt crows and similar species. In fact, there are some recorded cases where goshawks were able to exploit such mobbing behaviour in order to trick crows into close range, where the mob victim suddenly turned to grab one predaceously. In the following areas
Corvus species were the leading prey by number: the
hooded crow (
Corvus cornix) in the
Ural Mountains (9% by number), the
western jackdaw (
Coloeus monedula) in
Sierra de Guadarrama,
Spain (36.4% by number), the
rook (
Corvus frugilegus) in the
Zhambyl district,
Kazakhstan (36.6% by number). Despite evidence that Eurasian goshawks avoid nesting near
common ravens (
Corvus corax), the largest widespread corvid (about the same size as a goshawk at ) and a formidable opponent even one-on-one, they are even known to prey on ravens seldom.
Pigeons and doves with its fresh prey, a
common wood pigeon In
Europe, the leading prey species numerically (the main prey species in 41% of 32 European studies largely focused on the nesting season) is the
rock pigeon (
Columba livia). In areas where goshawk restrict their hunting forays to field and forest, they often catch another numerous pigeon, the
common wood pigeon (
Columba palumbus) (the largest pigeon the goshawk naturally encounters and is known to hunt). The latter species was the main prey in the diet of goshawks in the
Germany-Netherlands border area (37.7% of 4125 prey items) and
Wales (25.1% by number and 30.5% by biomass of total prey). It has been theorized that male goshawks in peri-urban regions may be better suited with their higher agility to ambushing feral pigeons in and amongst various manmade structures whereas females may be better suited due to the higher overall speeds to taking out common wood-pigeons, as these typically forage in wood-cloaked but relatively open fields; however males are efficient predators of common wood-pigeons as well. Studies have proven that, while hunting feral pigeons, goshawks quite often select the oddly colored pigeons out of flocks as prey, whether the plumage of the flock is predominantly dark or light hued, they disproportionately often select individuals of the other color. This preference is apparently more pronounced in older, experienced goshawks and there is some evidence that the males who select oddly-colored pigeons have higher average productivity during breeding.
Gamebirds , 1884), a painting of a goshawk at the moment of catching a
black grouse The Eurasian goshawk is in some parts of its range considered a specialized predator of
gamebirds, particularly
grouse. All told 33 species of this order have turned up in Eurasian and
American goshawks' diets, including most of the species either native to or introduced in North America and Europe. Numerically, only in the well-studied
taiga habitats of
Scandinavia do grouse typically take a dominant position. Elsewhere in the range, gamebirds are often secondary in number but often remain one of the most important contributors of prey biomass to nests. With their general ground-dwelling habits, gamebirds tend to be fairly easy for goshawks to overtake if they remain unseen and, if made aware of the goshawk, the prey chooses to run rather than fly. If frightened too soon, gamebirds may take flight and may be chased for some time, although the capture rates are reduced considerably when this occurs. Pre-fledgling chicks of gamebirds are particularly vulnerable due to the fact that they can only run when being pursued. This is fairly different from in southeastern
Alaska, where grouse are similarly as important as in Fennoscandia, as 32.1% of avian prey deliveries were adults, 14.4% were fledglings and 53.5% were nestlings. Eurasian goshawks can show somewhat of a trend for females to be taken more so than males while hunting adult gamebirds, due to the larger size and more developed defenses of males (such as leg spurs present for defense and interspecies conflicts in male of most pheasant species). Some authors have claimed this of male
ring-necked pheasant (
Phasianus colchicus), but these trends are not reported everywhere, as in southern
Sweden equal numbers of adult male and female ring-necked pheasants, both sexes averaging , were taken. While male goshawks can take black and hazel grouse of any age and thence deliver them to nests, they can only take capercaillie of up to adult hen size, averaging some , the cock capercaillie at more than twice as heavy as the hen is too large for a male goshawk to overtake. However, adult female goshawks have been reported attacking and killing cock capercaillie, mainly during winter. These average about in body mass and occasionally may weigh even more when dispatched. At the other end of the size scale, the smallest gamebird known to be hunted by Eurasian goshawk was the
common quail (
Coturnix coturnix). Domestic fowl, particularly
chickens (
Gallus gallus domesticus) are taken occasionally, especially where wild prey populations are depleted. While other raptors are at times blamed for large numbers of attacks on fowl, goshawks are reportedly rather more likely to attack chickens during the day than other raptors and are probably the most habitual avian predator of domestic fowl, at least in the temperate-zone. Particularly large numbers of chickens have been reported in
Wigry National Park,
Poland (4th most regular prey species and contributing 15.3% of prey weight),
Belarus and the
Ukraine, being the third most regularly reported prey in the latter two. In a study of British goshawks, the
red grouse (
Lagopus scotica) was found to be the leading prey species (26.2% of prey by number). In
La Segarra,
Spain, the
red-legged partridge (
Alectoris rufa) is the most commonly reported prey species (just over 18% by number and 24.5% by weight). The
red squirrel (
Sciurus vulgaris) is the most numerous mammalian prey in European studies and the sixth most often recorded prey species there overall. In
Oulu,
Finland during winter (24.6% by number), in
Białowieża Forest,
Poland (14.3%), in the
Chřiby uplands of the
Czech Republic (8.5%) and in
Forêt de Bercé,
France (12%) the red squirrel was the main prey species for goshawks.
Hares and rabbits , by
G. E. Lodge Eurasian goshawks can be locally heavy predators of
lagomorphs, of which they take at least 15 species as prey. Especially in the
Iberian peninsula, the native
European rabbit (
Oryctolagus cuniculus) is often delivered to nests and can be the most numerous prey. Even where taken secondarily in numbers in Spain to gamebirds such as in
La Segarra,
Spain, rabbits tend to be the most significant contributor of biomass to goshawk nests. On average, the weight of rabbits taken in La Segarra was (making up 38.4% of the prey biomass there), indicating most of the 333 rabbits taken there were yearlings and about 2-3 times lighter than a prime adult wild rabbit. In Europe, males have been recorded successfully attacking rabbits weighing up to , or about 2.2 times their own weight, while adult mountain hares overtaken by female goshawks in Fennoscandia have weighed from or up to 2.4 times their own weight. Despite historic claims that taking prey so considerably larger than themselves is exceptional beyond a small region of
Fennoscandia, there is evidence that as grouse numbers have mysteriously declined since 1960, adult mountain hare are increasingly the leading prey for wintering female goshawks, favouring and causing an increase of larger bodied females in order to overpower such a substantial catch. Eurasian goshawks also take about a half dozen species of
pikas in Asia, much smaller cousins of rabbits and hares, but they are at best supplementary prey for
American goshawks and of unknown importance to little-studied Eurasian goshawks.
Other birds Some 21 species of
woodpecker have been reported from Eurasian and American goshawk food studies around the world. With their relatively slow, undulating flight, adult and fledged woodpeckers can easily be overtaken by hunting goshawks, not to mention their habitat preferences frequently put them within active goshawk ranges. Most of the widespread species from Europe have been observed as prey, most commonly relatively large woodpeckers such as the
great spotted woodpecker (
Dendrocopos major) and the
European green woodpecker (
Picus viridis). All sizes of woodpeckers available are taken from the
lesser spotted woodpecker (
Dryobates minor) to the
black woodpecker (
Dryocopus martius). In many areas, Eurasian goshawks will pursue
water birds of several varieties, although they rarely form a large portion of the diet. Perhaps the most often recorded water birds in the diet are
ducks. All told, 32 waterfowl have been recorded in Eurasian and American goshawks' diet. Similarly, the
mandarin duck (
Aix galericulata) from Asia may be more vulnerable than most waterfowl at their tree nests. Although etymologists feel that the goshawk is an abbreviation of "goose-hawk", geese are seldom taken considering their generally much larger size. Nonetheless, four species have been taken, including adults of species as large as the
greater white-fronted goose (
Anser albifrons). Adult
common eiders (
Somateria mollissima), the largest northern duck at , have also been captured by goshawks. Various other water birds reported as taken include
red-throated loon (
Gavia stellata) chicks, adult
little grebes (
Tachybaptus ruficollis), adult
great cormorants (
Phalacrocorax carbo) (about the same size as a greater white-fronted goose), adult
crested ibis (
Nipponia nippon),
black stork (
Ciconia nigra) chicks and five species each of
heron and
rail. Among
shorebirds (or small waders), Eurasian and American goshawks have been reported preying on more than 22
sandpipers, more than 8
plovers, more than 10 species each of
gull and
tern, more than 2 species of
alcids and the
Eurasian stone-curlew (
Burhinus oedicnemus), the
Eurasian oystercatcher (
Haematopus ostralegus) and the
long-tailed jaeger (
Stercorarius longicaudus). Corvids as aforementioned are quite important prey. Although they take fewer passerines than
Accipiters do, smaller types of songbirds can still be regionally important to the diet. This is especially true of the
thrushes which are often delivered to nests in Europe. 17 species of thrush have been identified in goshawk food across their range. The numerous
Eurasian blackbird (
Turdus merula) is often most reported from this family and can even be the main prey at some locations such as in the
Netherlands (23.5% of prey by number) and in
Norway (just over 14% by number and two studies showed thrushes collectively make up nearly half of the prey items in Norwegian nests). All common
Turdus species are taken in some numbers in Europe, being quite regular and conspicuous in the woodland edge zones most often patrolled by male goshawks, especially while singing in spring and summer. Even where larger, more nutritious prey is present such as at pheasant release sites, the abundant thrushes are more often delivered to the nest because of the ease of capture such as in
Norway. Non-passerine upland birds taken by goshawks in small numbers include but are not limited to
nightjars,
swifts,
bee-eaters,
kingfishers,
rollers,
hoopoes and
parrots. Other miscellaneous rodents reported sporadically in the diet include
dormice,
Old World mice and rats,
zokors,
gophers and
jirds.
Insectivores are taken in low numbers including
moles,
shrews and
hedgehogs. In one case a juvenile
golden snub-nosed monkey (
Rhinopithecus roxellana), which was successfully taken by a goshawk.
Ungulates such as
deer and
sheep are sometimes consumed by goshawks but there is no evidence that they prey on live ones (as much larger accipitrids such as
eagles can sometimes do), but these are more likely rare cases of scavenging on carrion, which may more regularly occur than once thought in areas with harsh winter weather.
Alternative prey In a few cases, Eurasian goshawks have been recorded hunting and killing prey beyond birds and mammals. In some of the warmer drier extensions of their range,
reptiles may be available to them to hunt. Only one species of
snake is recorded from their diet, the small innocuous
grass snake (
Natrix natrix), at ; however about a half dozen
lizards are recorded in their diet, primarily from the
Iberian peninsula but also from the
Ural mountains. The only known location in the Eurasian goshawk's range where reptiles were taken in large numbers was
Sierra de Guadarrama,
Spain, where the
ocellated lizard (
Timon lepidus) was the second most numerous prey species.
Amphibians are even rarer in the diet, only recorded more than singly in one study each from
Spain and from
England.
Interspecies predatory relationships Eurasian goshawks are often near the top of the avian food chain in forested biomes but face competition for food resources from various other predators, including both birds and mammals. Comparative dietary studies have shown that the mean sizes of prey, both in terms of its size relative to the raptor itself and absolute weight, for goshawks is relatively larger than in most
buzzards in Europe. Studies show even buteonine hawks slightly larger than goshawks on average take prey weighing less than whereas average goshawk prey is usually well over this weight. This is due largely to the much higher importance of microtine rodents to most buzzards, which, despite their occasional abundance, are ignored by goshawks in most regions. In many of the ecosystems that they inhabit, northern goshawks compete with resources with other predators, particularly where they take sizeable numbers of lagomorphs. About a dozen mammalian and avian predators all primarily consume
European rabbits and
hares alongside goshawks in the Iberian peninsula where these became primary staple foods. Like those co-habitant predators, the goshawk suffers declines during the low portion in the lagomorph's breeding cycles, which rise and fall cyclically every 10 to 12 years. However, even where these are primary food sources, the Eurasian goshawk is less specialized than many (even
Eurasian eagle-owls, one of the most generalist avian predators, becomes an extremely specialised lagomorph hunter locally, to a greater extent than goshawks) and can alternate their food selection, often taking equal or greater numbers of squirrels and woodland birds. Due to this dietary variation, the Eurasian goshawk is less affected than other raptorial birds by prey population cycles and tends to not be depleted by resource competition. On occasion, goshawks are robbed of their prey by a diversity of other birds, including
harriers, other
hawks,
eagles,
falcons and even
gulls. Eurasian goshawks have been shown, in some but not all areas, to outcompete and possibly lower the productivity of the
common buzzard (
Buteo buteo) when their ranges overlap. Usually, however, the dietary habits and nesting preferences are sufficiently distinct and thus affect neither buzzard nor goshawk populations. Both can mutually be very common even when the other is present. To many other raptorial birds, the Eurasian goshawk is more significant as a predatory threat than as competition. The Eurasian goshawk is one of the most dangerous species to other raptors, especially to those considerably smaller than itself. In many cases, raptors of any age from nestlings to adults are taken around their nests but free-flying raptors too are readily taken or ambushed at a perch. One example is a study from
northern England,
common kestrels (
Falco tinnunculus), which average about , recorded as prey at goshawk nests (mainly in March and April) numbered 139, a larger number than kestrels recorded alive in the spring in the same area. In the
Veluwe province of
the Netherlands, the percentage of nest of
European honey buzzards (
Pernis apivorus), weighing on average , predated by goshawks increased from a little as 7.7% in 1981–1990 to 33% in 2000–2004. As their habitat preferences may overlap with goshawks, all
Accipiter and
Tachyspiza species encountered may be predated in multiple cases, including the
Eurasian sparrowhawk, the
levant sparrowhawk (
Tachyspiza brevipes), and the
Japanese sparrowhawk (
Tachyspiza gularis). Other assorted accipitrids of up to their own size to be predated by goshawks include the
black kite (
Milvus migrans), the
red kite (
Milvus milvus), the
western marsh harrier (
Circus aeruginosus),
Montagu's harrier (
Circus pygargus), the
pallid harrier (
Circus macrourus), the
booted eagle (
Hieraaetus pennatus) and buzzards up to size of the
common buzzard can be taken. Even raptors somewhat larger than a Eurasian goshawks have been considered as prey, although it is not clear whether adults are among the victims, including the
crested honey-buzzard (
Pernis ptilorhynchus) and the
lesser spotted eagle (
Clanga pomarina). Outside of the accipitrid group, heavy predation on different varieties of raptorial birds by Eurasian goshawks can be significant. Many types of
owl are taken and in
Europe, the Eurasian goshawk is the second most prolific predator of owls behind the
Eurasian eagle-owl (
Bubo bubo). In
Bavaria,
Germany, the
long-eared owl (
Asio otus) was the second most common prey species for nesting goshawks. In addition, multiple species of
falcon are preyed upon by goshawks. Adult falcons of small species such as
kestrels and
merlins (
Falco columbarius) can be overpowered quite easily if they can manage to surprise the prey. Larger falcons have turned up in the diet as well, including the
saker falcon (
Falco cherrug), although the prey may have been nestlings. Brief aerial skirmishes between goshawks and
peregrine falcons (
Falco peregrinus) have been described but neither species is known to have killed one another in the wild. In
Schleswig-Holstein,
Germany, at least four small passerines species were recorded as nesting close to active goshawk nest, due to the incidental shelter that the fierce goshawks inadvertently provides from smaller raptors which are their main predators. Such raptors, including
Eurasian kestrels,
Eurasian sparrowhawks and long-eared owls, not only avoid goshawk activity where possible but also were found to have lower nest productivity any time they nested relatively close to goshawks per the study. Domestic carnivores are taken on scarce occasion, including
dogs (
Canis familiaris) and
cats (
Felis catus), predominately young specimens but the remain of an adult cat was found in a goshawk nest. Eurasian goshawks have also been recorded as feeding on much bigger predators such as the
red fox (
Vulpes vulpes) and
raccoon dog (
Nyctereutes procyonoides), but it is not clear whether these were actual kills, as many may be encountered as already dead carrion. The red fox is a clear competitor for resources with Eurasian goshawks. It was found in
Norway that goshawk numbers were higher when
voles were at peak numbers, not due to voles as a food source but because foxes were more likely to eat the rodents and ignore grouse, whereas during low vole numbers the foxes are more likely to compete with goshawks over grouse as prey. A decrease of the fox population of Norway due to
sarcoptic mange was found result in an increase of grouse numbers and, in turn, Eurasian goshawks. In some areas, red foxes have been found to steal up to half of the goshawks' kills. Unlike the predators at the top of the avian food chain such as
eagles and the largest
owls, which are rarely endangered by predation as adults, the Eurasian goshawk is itself susceptible to a fairly extensive range of predators. The most deadly are likely to be the
Eurasian eagle-owl which not only predates goshawks of any age and at any season but also opportunistically take over their prior nests as their own nesting site. Other larger raptorial birds can threaten them. Other avian predators known to have successfully preyed on goshawks including adults (usually in singular cases) include
white-tailed eagle (
Haliaeetus albicilla),
Bonelli's eagle (
Aquila fasciata),
eastern imperial eagle (
Aquila heliaca),
snowy owl (
Bubo scandiacus), and
Ural owl (
Strix uralensis). The same mammalian predators that sometimes compete for food with Eurasian goshawks also sometimes kill them, with the nestlings, fledglings and brooding females, all with impaired flight due to their wing feather moults, seemingly the most vulnerable. Other mammals capable of climbing trees have been observed or inferred to predate goshawks, either mostly or entirely young in the nests, including
wolverines (
Gulo gulo). Overall, the most recorded nest depredations are by eagle-owls, with
martens and
corvids usually only preying on goshawk nestlings when low food supplies cause the goshawks to have lower nest attendance (and presumably effect these predators to the extent that they take the risk of coming to the goshawk nest). Apart from aforementioned predation events, Eurasian goshawks have at times been killed by non-predators, including prey that turned the tables on their pursuer, as well as in hunting accidents. In one case, a huge group (or murder) of
hooded crows heavily mobbed a goshawk that they caught in a relatively open spot, resulting in a prolonged attack that ended up killing the goshawk. In another instance, a goshawk drowned while attempting to capture a
tufted duck (
Aythya fuligula). One young goshawk managed to escape a red fox that had caught it with a chewed wing, only to drown in a nearby creek. Another, and rather gruesome, hunting mishap occurred when a goshawk caught a large mountain hare and, while attempting to hold it in place by grasping vegetation with its other foot, was torn in half. == Breeding==