Spotted eagle-owl | |
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At night, Tswalu Kalahari Reserve, South Africa | |
Scientific classification | |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Aves |
Order: | Strigiformes |
Family: | Strigidae |
Genus: | Bubo |
Species: | B. africanus |
Binomial name | |
Bubo africanus Temminck, 1821 |
The spotted eagle-owl (Bubo africanus) is a medium-sized species of owl, one of the smallest of the eagle owls. Its length is 45 centimetres (18 in) and its weight is from 480 to 850 grams (1.1 to 1.9 lb). It has a 100 to 140 centimetres (39 to 55 in) wingspan. The facial disk is off white to pale ochre and the eyes are yellow. It has prominent ear tufts, and the upper body is dusky brown, the lower parts off-white with brown bars. Prior to 1999 the spotted eagle-owl was considered conspecific with the greyish eagle-owl, but now it is classed as a separate species.
Its prey consists of small mammals, birds, insects, frogs, and reptiles. It often swallows quite large prey whole, with much head-jerking, and if the object is really challenging, pausing and resting with the mouth full. Prey too large for such treatment it will tear in the normal raptorial fashion, and it also tears shreds off prey to feed nestlings. The male will hunt and bring food when the female cannot leave the nest. Sometimes, even in conditions verging on starvation, he will tear the head off a mouse, but bring the body for the female to feed to the young, or to eat herself if the eggs have not yet hatched. The species is a non-specialised feeder, in contrast to say, the barn owls (Tyto) and is accordingly itinerant, remaining in a given region to hunt for a few weeks or months, then moving on when the local prey is no longer plentiful or easy to catch. Typically it will return at odd intervals of a year or two, depending on local conditions. An adult pair is typically very aggressive in defence of its hunting territory, and one obstacle for an adolescent to overcome is to find good feeding grounds where there are no incumbent adults to eject or kill it.
The calls are generally typical, musical eagle-owl hoots. Generally the male call with two hoots: "Hooo hooopoooo" and the female answers with three, with less stress on the middle note: "Hooo hoo hooo". The young do not hoot till effectively adult, but from a very young age they will hiss threateningly and snap their beaks castanet-like if alarmed. These sounds they make throughout life, generally in a threatening attitude with head down and wings spread sideways to present their upper surfaces forward, umbrella-like. They might present such behaviour either as a challenge to rival owls or when defending nest or young against enemies. The young at least have a whickering call of protest or annoyance when handled. In a comfortable social situation the youngsters have a soft croaking "kreeep" that they are prone to repeat at regular intervals of a few seconds. If they suspect that they have lost their company, the calls increase in frequency and they are likely to go hunting for their companions.