CROWNED EAGLE

The bird was named Crowned Eagle because it raises a double crest on its head when it is alarmed or excited.  It gives a loud ‘kwee kwee' to warn any intruder.

The crowned eagle has huge feet with strong, sharp talons. The talons are a think as a human finger and has massive muscles. The crown eagle such equipped can kill a prey up to six times bigger than itself.

Birds of prey kill by catching the victim with its feet and slowly tighten the grip. This makes the talons go into the victims and the hind talon on the rear toe is longer and more fatal. They are like daggers going into the prey.  If the catch is not dead at once it will by the crashing power of their grip.

For the bird it is important that its prey is killed quickly. If it is not, it can lash out and injured the bird.

Birds of prey are catching mostly victims smaller than themselves to avoid injuries.  The crowned eagle has evolved power and skill to catch big animals. This ability gives the crowned eagle the advantage to attack animals such as monkeys.  A further advantage is there less competition and therefore hardly any food shortage. It also has to hunt less often and this reduces the risk of injuries.

HUNTING FOR FOOD

The crowned eagle hunts mostly in the early morning or late evening.  It hunts mostly in areas where monkeys are common.

Monkeys are not easily caught. They are in groups which give plenty of watchful eyes and they are agile and intelligent. They have a further protection from the canopy of leaves. Their disadvantage is that they are noisy and the eagle with it highly sensitive hearing can hearing them miles away. Some eagles fly high and swoop down onto their prey but the crowned eagle is a stealthy hunter and stalks its food.

The crowned eagle has the same ability as owls; it can fly without wing beats making a noise.  Most of the time it sits in the tree quietly watching and waiting for a prey to come a long. If it thinks it is useless it will fly to another tree and sits there again.  If it sees an animal trotting unaware under the tree it drops like a stone and kills it instantly.

It also uses other methods.  If it hears troops of monkeys it launches a surprise attack.  It will fly low under coverage of trees and foliage and gets as close as possible. It also could fly the long way around to use tenser foliage. Once it thinks it is close enough the eagle will fly below them. It uses the silhouette to pick the right victim.  It could be a monkey with the back to the eagle or one with a clear line of approach. At this moment the bird accelerates. The broad wings enable the bird to fly upwards quickly.  Its muscular legs swing forward resembles a mechanical grab. The feet strike the monkey, the talons driving deeper and deeper.  The strength of its wings drives the bird upwards and it looks like rocket. Still grasping its near-lifeless  victim.  It burst through the canopy and gets above the trees.

It is assumed that the crown eagle mate for life. They also use each other to distract the monkeys by one and the other catching it. After a successful hunt they share their prey. This is unusual for eagles.  If the victim is a big one they dismember the leftovers and wedge it into a tree and out of sight. Therefore, they always have a constant supply of food.

BREEDING

The pair has a territory with can be up to 16sqkm. They marked their boundaries by switchback swoops, souring climbs and at the same time giving high-pitched calls. This gives other crown eagle the message the territory is already occupied.

The crown eagle nest in big forest trees in a river valley. It is thought that many crown eagles used it for generation to rear their young. Every nesting season the adult bird adds more material and an ancient nest could measure 3m deep and 2m across.

Mostly the bird lays one egg but sometimes two. In this case the older chick will kill the younger one most of the time. The reason for this is that the chick needs its parent’s full attention to grow and survive.  After the young eagle left its nest the parents will feed it up to a year. During this time it will have to learn how to be a successful hunter.  Since they have to look after the chick for a full year it means that they can only breed every other year.

The chick only grows its adult plumage when it is 15 months old. Till such time it’s feathers have a much paler colour and a white crest.

It takes great skill to hunt and kill and the young eagle will go through a lean period. The hunger will drive it to take risk and this will lead to injuries or death.

HABITAT

The crown eagle is relying on forests for its habitat and hunting.  It wasn’t  so long ago the crowned eagle was seen from Africa south of the Sahara desert,  from Guinea in west Africa to Kenya in the east, and south to the coast of Cape Province.  However, as it is always the same story the habitat is constantly reduced and not only the eagle loses its territory but also the prey.