Sunday, December 28, 2008

secretary bird

RangeThe Secretary Bird is only found in Africa south of the Sahara desert. Its preferred habitat is open grass plains and steppes, and savannah and bushveld when it is not too dense.In some areas it has learned to tolerate cultivated country, stalking through fields of wheat or young maize. It generally avoids grass that it cannot conveniently walk through.
DietThe staple diet of the Secretary Bird is a combination of small ground mammals and large insects, some young birds, lizards, snakes and occasionally larger creatures up to the size of a young hare.Its equipment for killing differs from all other birds of prey in that its kills by stamping with its long, powerful legs, engaging the short rear talon with the base of the skull of its prey with extreme force and absolute accuracy.
VoiceThe Secretary Bird is usually a very quiet bird. At the nest and during nuptial display it makes a variety of hoarse, croaking calls.It is often noisy on the roost at night, making mewing cries. The young in the nest sometimes call with the head thrown back like the Bald Eagle
Status and behaviour in the wild
This unusual bird is unique, and is grouped in a family by itself. There is only the one species, which is found in Africa south of the Sahara. The scientific name Sagittarius serpentarius can be taken to mean 'The Archer of Snakes'. This relates to the hunting technique of these birds. They have, in the past, been called the Long-legged Marching Eagle, although they are not related to eagles.The Secretary Bird is very largely terrestrial - moreso than any other bird of prey. It is an accomplished flier and, when in the air it presents a silhouette which is broad-winged and fingered with long legs and tail projecting behind.Secretary Birds are very much at home on the ground. Their long legs allow these birds to hunt for prey in long grass. They can run very fast. Although spending most of the day on the ground, Secretary Birds are graceful fliers. They roost and nest in trees, and will take to the wing if danger is present. The bright orange or yellow eye patches seen on these birds are believed by some to be a distraction to venomous snakes. A brightly coloured face is a feature often seen on raptors which eat a large number of snakes.Its method of killing its prey - stamping with the long legs and the short, bluntish but extremely hard rear talon is also unique as are its extremely long legs - the legs which have earned it the nickname of 'long-legged marching eagle'The cresting is more marked than on any other bird of prey, and it is the combination of what look like quills behind the ears and knee-breeches which earned its name, by allusion to the legal secretaries of the 19th century.The Secretary Bird roosts in flat-topped acacia trees. A couple of hours after dawn, it drops to the ground, where it walks twenty miles or more each day through the grassland, at an average speed of around 3mph (1.3 m/s), sometimes resting in the shade of a tree during the hottest hours. From time to time it makes a dash to one side, or opens its wings and runs rapidly for a few paces to catch some prey.The name Secretary Bird is thought to have originated from the 19th century when these birds were first seen by Europeans. At that time, secretaries used to wear grey tail coats and knee breeks (also called 'plus twos' or 'knickerbockers'). They would also carry a number of goosequill pens behind their ears. The Secretary Bird has many of these features such as feathers behind the head, dark feathers halfway down the legs and the appearance of a grey tail coat.These birds are renowned for their ability to catch snakes, although they probably do not catch as many as might be imagined. They will also catch and eat virtually anything which is not too big to swallow such as lizards, insects and small mammals. Prey is usually chased along the ground and, once caught, repeatedly thumped in the head by the short, sharp rear talon. When dispatching prey, the bird will stand slightly back, spread both wings, erect the crest of feathers at the back of the head and fire away with both talons. Two very long tail feathers will also drop down. The spread wings and feathers act as a false target for venomous creatures, particularly snakes. The two tail feathers are designed to look like a third leg. Because feathers have hollow quills, the bird will not be poisoned if it is bitten in the feathers.Towards sunset it moves back to its roosting trees, where it will go to roost at least an hour before dark.Two or three eggs are laid in the tree-top nest. These are incubated by the female for about 45 days. The young leave the nest after 65-80 days.