Dietary biology of the Eurasian eagle-owl
Generally speaking, there appears to be rather strictly adhered size hierarchy among birds of prey and the very largest raptorial prey attacked by Eurasian eagle-owl tend to roughly equal to their own size. Larger raptors, such as eagles and vultures, seem to be largely invulnerable to eagle-owls. However, in Scandinavia, there are two cases of eagle-owls preying on “fairly large” nestlings of white-tailed eagles ("Haliaeetus albicilla"). Given the size, average adult weight of , and formidable character of this eagle, it is possible that the young of other raptors larger than themselves may too be attacked. Eastern imperial eagles ("Aquila heliaca"), which are nearly as large as the white-tailed eagle at an average weight of , have been killed by eagle-owls in Kazakhstan. Remarkable, considering the greater threat that the eagle normally poses to the eagle-owl than vica versa, it appeared a golden eagle was amongst the prey remains found around a nest in the French Pyrenees. Cases in Spain where large, formidable birds of prey, the Egyptian vulture ("Neophron percnopterus") and Bonelli's eagle, that are roughly equal in size to the eagle-owls, both weighing just over , have been predated, these seem to be taken from the nest or shortly after independence and rare occurrences. However, in Turkey, the eagle-owl is apparently a regular and serious predator of Bonelli's eagles. The Eurasian eagle-owl predates the largest members of the most species-rich diurnal raptor genera: the northern goshawks from the "Accipiter" genus, the upland buzzards from the "Buteo" genus and the gyrfalcons ("F. rusticolus") of the "Falco" genus. Additional large raptors, i.e. those that can average or more in body mass, taken as prey include osprey ("Pandion haliaetus"), the red kites ("Milvus milvus"), short-toed eagles ("Circaetus gallicus"), the greater spotted eagle ("Clanga clanga"), the lesser spotted eagle ("Clanga pomarina"), and the rough-legged buzzards ("Buteo lagopus") and saker falcons ("Falco cherrug"), in both of which females average more than . The taking of rough-legged buzzards and snowy owls must be confined to full-grown victims, since they nest further north than Eurasian eagle-owls. Eurasian eagle-owls also hunt the smallest raptors available, including those such as lesser kestrels ("Falco naumanni") and Japanese sparrowhawks ("Accipiter gularis") that weigh less than . Some of these are cases of eagle-owls killing nestlings or fledglings but they can easily overtake adult buzzards, goshawks and falcons of any size.
Eurasian woodcock
This species is the woodcock found through most of temperate and subarctic Eurasia. Northern and Asian populations migrate to southern Europe or the Indian Subcontinent, respectively. Birds in milder western European countries and on Atlantic islands are resident. The populations breeding in north-west and southern Europe are mostly sedentary. The birds' spring migration commences in February; breeding territories are reached between March and May.
The Eurasian woodcock has a large range, with an estimated Global Extent of Occurrence of 10 million square kilometres and a population of an estimated 15 million to 16 million birds. Because of its large range, stable population trend and large population size, the species has been evaluated as Least Concern. The most important threat to the population of the Eurasian woodcock in the breeding range is the increased fragmentation of its woodland habitat. At other times of year, a reduction in the amount of permanent grassland and an increase in the intensification of farming are also threats, and the species' susceptibility to avian influenza may have an impact in future.