Dietary biology of the Eurasian eagle-owl
In the Iberian peninsula, the Eurasian eagle-owl is part of a complex guild of predators that have evolved to survive mostly on European rabbits. Among this guild, golden eagles ("Aquila chrysaetos") were recorded per one study to rely on rabbits for 40% of the diet, the eagle-owl for 49% of the diet, the Spanish imperial eagle ("Aquila adalberti") for 50% of the diet, the Bonelli's eagle ("Aquila fasciata") for 61% of the diet and the Iberian lynx ("Lynx pardinus") for 79% of the diet. Elsewhere, the Spanish imperial eagle and eagle-owl are considered to outflank the golden and even the Bonelli's eagle as the most specialized avian predator of rabbits in the Iberian region. Other predators, such as common buzzard ("Buteo buteo"), northern goshawk ("Accipiter gentilis") black kite ("Milvus migrans") Iberian wildcat ("Felis silvestris tartessia"), red fox, stone marten ("Martes foina") and introduced Egyptian mongoose also prey heavily on rabbits in Spain, but are more generalized and less reliant than the above predators. All these powerful predators do not generally compete directly for food but conflicts may ensue over the rights to territories and nesting sites amongst the birds. Being nocturnal in activity, however, the Eurasian eagle-owl does not tend to compete as directly as do the three eagle species and even these are discreetly segregated by habitat preferences, the goldens preferring open, steep cliffs, the Bonelli's favoring densely vegetated areas mixed with rocky spots and the imperial favoring relatively flat open woodlands. Among these eagles, the golden eagle tends to have the most similar habitat preferences to the Eurasian eagle-owl and across a broad band of overlapping distribution, the two are considered nearly ecological equivalents by day and night. However, good-sized female golden eagles are up to twice as heavy as an average eagle-owl, so seem to have a considerable advantage in size and power. Conversely, to support their large size and large territory needs, the golden eagle cannot survive on small and diverse prey nearly as successfully as the eagle-owl. Among the Iberian peninsula rabbit-eating guild, the species with wider ranges, the eagle-owl and the golden and Bonelli's eagles, have had some degree of success living off of alternate prey following the devastation of the rabbit population due to rabbit haemorrhagic disease. The two rabbit predators endemic to Iberia, the Iberian lynx and Spanish imperial eagle, have been devastated by the reduction and other causes and both are threatened species today.
Coyote
The coyote is roughly the North American equivalent to the Eurasian golden jackal. Likewise, the coyote is highly versatile in its choice of food, but is primarily carnivorous, with 90% of its diet consisting of meat. Prey species include bison, deer, sheep, rabbits, rodents, birds, amphibians (except toads), lizards, snakes, fish, crustaceans, and insects. Coyotes may be picky over the prey they target, as animals such as shrews, moles, and brown rats do not occur in their diet in proportion to their numbers. More unusual prey include fishers, young black bear cubs, harp seals and rattlesnakes. Coyotes kill rattlesnakes mostly for food (but also to protect their pups at their dens) by teasing the snakes until they stretch out and then biting their heads and snapping and shaking the snakes. Birds taken by coyotes may range in size from thrashers, larks and sparrows to adult wild turkeys and, possibly, brooding adult swans and pelicans. If working in packs or pairs, coyotes may have access to larger prey than lone individuals normally take, such as various prey weighing more than . In some cases, packs of coyotes have dispatched much larger prey such as adult "Odocoileus" deer, cow elk, pronghorns and wild sheep, although the young fawn, calves and lambs of these animals are considerably more often taken even by packs, as well as domestic sheep and domestic calves. In some cases, coyotes can bring down prey weighing up to . When it comes to adult ungulates such as wild deer, they often exploit them when vulnerable such as those that are infirm, stuck in snow or ice, otherwise winter-weakened or heavily pregnant, whereas less wary domestic ungulates may be more easily exploited.