Colours of Wildlife: The Spotted Eagle Owl
Created | Updated May 13, 2012
Willem is a wildlife artist based in South Africa. He says "My aim is simply to express the beauty and wonder that is in Nature, and to heighten people's appreciation of plants, animals and the wilderness. Not everything I paint is African! Though I've never been there, I'm also fascinated by Asia and I've done paintings of Asian rhinos and birds as well. I may in future do some of European, Australian and American species too. I'm fascinated by wild things from all over the world! I mainly paint in watercolours ... but actually many media including 'digital' paintings with the computer!"
Spotted Eagle Owl
Today’s picture is a Spotted Eagle Owl, Bubo africanus.
Eagle owls are so called because they are the largest and most powerful of the owls. The genus Bubo contains several more African species, as well as many other ones in Europe and Asia. Recent investigations suggest that the Asian Fishing Owls previously placed in the genus Ketupa might also need to be included in Bubo. The Snowy Owl has also been moved to this genus and is now called Bubo scandiacus and is one of three eagle owl species occurring in the Americas. Owls are not closely related to eagles, hawks, falcons and other birds-of-prey. Their relationships to other birds are still being worked out. It is possible that their closest relatives are the nightjars, potoos and frogmouths.
The Spotted Eagle Owl is widespread in the dry African savannah regions, and even occurs in open grassland, desert and semi–desert, provided that there is some kind of shelter such as rocky hills and ridges. It is also a species that has adapted well to people, and can be found in towns and cities where it often nests on buildings. It is only absent from dense rainforest. North of the Equator it is replaced by the very similar Greyish Eagle Owl, Bubo cinarescens. It is not a particularly large eagle owl, being dwarfed by the Giant Eagle Owl, Bubo lacteus, and a few other African owl species. It reaches a total length of 45 cm/18" and a weight of just under 1 kg/2.2 lbs.
This is one of the 'eared' owls. The ear tufts are not real ears . . . they are more like decorations. In the small eared owls of the genus Otus the tufts may help with camouflage, disguising the bird's outline as it sits with its body pressed against
the bark of a tree. Even big owls like this one can be surprisingly hard to spot sitting in a tree, so maybe there's a camouflage aspect with them as well. Another possibility is that the ear tufts enhance the similarity between the face of the owl and that of a wild cat or fox, which may help the owl to intimidate other animals or birds that might threaten it.
But owls' real ears are very important to their way of life. The actual ears are long slits at the side of the head, concealed in the big, fluffy feathers of the face and head. The feathers of the face form a round and flattened 'disk' that acts almost like a radar dish, channeling and focusing sounds towards the ears. It is more thanks to their excellent hearing than their sense of sight that owls are able to hunt so effectively at night. Owls also have ears that are asymmetric – the ear slit on one side being higher than that on the other – to help them gauge distance in the dark. When listening to a potential prey item they will turn, twist, bob and weave their heads, and the delay in the sound coming to one ear compared to the other will tell them exactly which direction the sound is coming from. Owls can hunt in total dark, provided their prey is making some noise. In the savannahs there's always dry leaves, twigs and grass on the ground that even a mouse will cause to rustle as it moves about.
But there's no mistaking that their sense of sight is excellent as well. Their eyes are huge … so big in fact that they cannot turn them in their sockets. This adds to the disconcerting intensity of an owl's stare. To compensate for these immobile eyes, owls have very flexible necks, and can turn their heads almost completely around. They can also swivel their heads, turning them almost upside down. They can also 'fix' their heads in place, keeping their stare glued to one spot irrespective of what their body is doing. A fun thing to do if you ever have the chance to handle a tame owl is to put it on your arm and then move your arm forward, backward, up and down … the owl will keep its head in one place most of the time, while its body moves around below it, stretching and bending its neck to accommodate the movements of its body and your hand.
Spotted Eagle Owls eat prey ranging in size from insects like beetles and crickets, through rodents and small birds to squirrels and medium–sized birds like doves and pigeons. Exceptionally large prey items include partridges, Lanner Falcons, Hornbills, bushbabies and hares. They will even catch snakes occasionally. Unlike other owl species like barn owls, they will not swallow large prey items whole, but will use their strong bills and feet to rip it into smaller pieces. The method of hunting is usually to sit on a tall perch, making frequent use of telephone poles, and scan the ground below, swooping down to catch prey. Like other owls their flight is extremely silent, giving no warning of their approach. It appears that they also often use roads to hunt, watching for small creatures trying to cross. An unfortunate result of this is that many owls are killed by cars. One owl has been seen following a honey badger as it forages, looking out for small creatures flushed from their hiding places. Lastly, eagle owls will sometimes chase flying prey … one has been recorded catching a fruit bat in flight. Like other owls do, they regurgitate indigestible pieces such as bones and matted fur in 'owl pellets', dropping them around the nest site.
The call of this owl is a typical hooting, the male and female often 'singing' together, the one answering the other so rapidly that is sounds like just one bird calling. They pair up and remain monogamous for life; only if one dies will the other one seek a new mate. The nest can be anything from a shallow scrape in the ground, to a hole up in a tree, or a ledge on a building, or any kind of cavity, natural or artificial. They will also use the huge nests of Hamerkops or Sociable Weavers, laying their two to four eggs on top of them. One eagle owl mom has been seen to incubate a light bulb along with her real eggs; it had been left on the ledge by people who were photographing her, and she rolled it into her nest. The female incubates alone but her mate will bring her food. When the chick hatch, he will continue bringing food for her as well as the chicks. When they are two weeks old the female will start leaving them to hunt as well. They leave the nest when they're about six weeks old, but the parents will still feed them for another five weeks. By then they'll have learnt to hunt, and will disperse.
This is at present one of Africa's most abundant owl species, widespread and adaptable, and not threatened.
