Bubo bubo Eurassian Eagle Owl Class: Aves. Order: Strigiformes. Family: Strigidae. Other names: Eagle owl
Physical Description: The coloration of the eagle owl is generally a rich fawn color interspersed with dark brown stripes. In viewing the bird from a distance the color appears to be reddish brown with black bars. The facial half-disk is finely marked and on some specimens there are white markings on the throat. The eyes of the eagle owl are large in size and a very bright orange hue. The beak is black and very prominent. The toes, which are extensively feathered, are very long and powerful ending in long, black talons. Eagle Owls have large ear tufts; possibly the owl’s mechanism for making it appear more menacing and also for communication purposes. Eagle owls are very vocal owls. It has to be noted that the female of this particular species is always approximately one third larger than the male. The height of the eagle owl ranges between 2-2.5’, while the wingspan ranges from approximately 5.5-6’. The weight of the male can vary from 4-5.5lbs, while a large female can weigh up to 9lbs.
Diet in the Wild: Eagle Owls will eat almost anything the moves - from beetles to birds, even roe deer fawns. The major part of their diet consists of mammals (preferring rabbits). Tawny owls, Long-eared Owls, Goshawks, Peregrine Falcons, Rough-legged Buzzards, Gyrfalcoms, Ravens, and several other birds of prey have been recorded as prey. Farmyard cats have even been reported falling prey to these owls.
Diet at the Zoo: chicks, rats, mice
Habitat & Range: Eastern & Southern Europe, Northern Asia in Rocky areas, woodlands, grasslands, and even deserts entirely devoid of trees
Life Span: Up to 20 years in the wild, up to 60 years in captivity
Perils in the wild: On rare occasions has been killed by a Golden Eagle or White-tailed Eagle, but it is far more common for the Eagle Owl to kill other birds of prey including owls.
Physical Adaptations: The talons are larger than leopard’s claws. All owls posses a zygodactyl fourth digit (the ability to reverse the fourth digit on its foot so that the talon either points forward or backwards as needed). Heavily compressed, eagle-like bill. Facial disc collects sounds and concentrates the sounds to the ear, allowing the owl to gauge direction and distance of possible prey. Owls have broad wings with large surface areas that help them to float through the air without flapping too much. Less flapping makes less noise. On both the primary and secondary feathers, there are comb-like structures at the edge of the feather that are responsible for muffling the sound of the air going over the wing – this essentially makes an owl silent when they fly. Also, an owl’s feathers can separate from each other on the same wing; therefore, the air flows over each of the individual feathers and their comb-like 09/04/2012
structures, which maximizes how silently an owl flies. Almost-silent flight enables the birds to hear the tiny sounds produced by their small mammal prey and approach them undetected. An Owl cannot move its eyes, it can only look straight ahead. Owls make up for this by being able to turn its head 270˚around, and almost upside-down. It is able to achieve this by having a long and very flexible neck. An owl's neck has 14 vertebrae; twice as many as humans. To protect their eyes, Owls are equipped with 3 eyelids. They have a normal upper and lower eyelid, the upper closing when the owl blinks, and the lower closing up when the Owl is asleep. The third eyelid is called a nictitating membrane, and is a thin layer of tissue that closes diagonally across the eye, from the inside to the outside. This cleans, protects, and moistens the surface of the eye. Owls use of parallax is facilitated by eyes and ears that are widely separated and forward facing; one of the most distinctive features of this family of birds.
Behavioral Adaptations: Nocturnal Live solitarily or in mated pairs The call of the Eagle Owl is a deep resonant ooh-hu with emphasis on the first syllable for the male, and a more high-pitched uh-Hu for the female. Each member of an Eagle Owl population has a distinct vocalization and can be reliably identified by voice alone. When menaced, they hiss loudly and puff out their feathers to increase their size.
Reproduction and Development: This species usually nests on cliff ledges, crevices and caves, in forests, they nest on the ground. The species has always been considered to be monogamous, but some cases of bigamy have been recorded recently Lying generally begins in late winter, sometimes later. One clutch per year of 1-6 white eggs are laid Eggs are incubated by the female alone, starting from the first egg, for 31–36 days. During this time, she is fed at the nest by her mate. At least one chick usually dies before fledging and is eaten by the remaining chicks. Fledged young are cared for by both parents for around 20–24 weeks. They begin to fly around 7-8 weeks old and require parental care for some weeks after. The first winter of an Eagle Owls life is a time of great danger. The young technically reach sexual maturity by the following year, but do not normally breed until they can establish a territory at around 2–3 years old
Additional Information: Considered one of the largest living owls; Snowy Owl and Blakiston’s Fish Owl compare in bulk and weight. Berreaux’s Eagle Owl rivals the Eagle Owls wingspan. An eagle-owl’s flight is powerful and fast with shallow wing beats and long, fast glides. This owl will also soar on updrafts. This type of flight is similar to that of a soaring Red-tailed Hawk. Can catch other birds in mid-air. Largest prey recorded was a roe deer weighing 29lbs.
Conservation Status: Least concerned
Conservation Efforts: Not globally threatened, although rare or uncommon through most of its range. Becoming very scarce in parts of Europe due to urbanization and habitat fragmentation. 09/04/2012
Sources: Cincinnati Zoo & Botanical Gardens http://us.123rf.com/400wm/400/400/isselee/isselee0804/isselee080400305/2935333-eurasian- eagle-owl--bubo-bubo-22-months-in-front-of-a-white-background.jpg http://www.conservationcentre.org/EOyng.html http://www.arkive.org/eurasian-eagle-owl/bubo-bubo/ Owls of the World Rob Hume Owls of the World John Burton
09/04/2012