When a Martial Eagle – perched on top of one of the lonely thorn trees in the Mara – looks down at you with its piercing ambers eyes, you can feel its presence and power.
‘Majestic’ is an adjective tossed around all too frequently when describing birds of prey, but it is difficult to come up with a better one for the Martial Eagle. This is the largest of Africa’s eagles weighing up to 6 kg and measuring 84 cm (nearly three feet) from bill to tail tip. The wingspan is 260 cm, a little short of three metres.
Females are significantly larger than males – a feature common to most eagles and hawks (the measurements above refer to females). Paired for life, it is she that spends most time on the nest, incubating and shielding the hatchling from the sun and any dangers. He is more agile and able to capture a wider range of prey – invaluable when the developing eaglet has such an appetite.
As large apex predators, the Martial Eagle pair requires a vast territory, with nesting pairs never closer than 10 km to one another. Their chief avian prey is guineafowl, francolins and bustards, with storks, herons, geese and hornbills also being taken. The Martial is particularly fond of large monitor lizards – a formidable reptile but seemingly worth the risk and effort. Other lizards and snakes are taken opportunistically. In some areas, mammals are preferred above birds and reptiles, with hares, mongooses, squirrels, hyraxes, foxes, steenbok and dikdiks making up the bulk of the eagle’s diet. In the Mara, newborn gazelles and impala are often taken, and warthog piglets are always at risk.
In its favoured open habitat, the method of hunting is to soar high above the plains, identify a target, then swoop down with the sun at its back. If it goes as planned, then the prey is caught by surprise, half-blinded by the sun as the eagle strikes it with such force that it is either killed instantly or bowled over and held firmly with its talons. Tough and scaly monitor lizards may take a while to submit but most other prey is rapidly dispatched.
Life is hard for the young eagles that fledge successfully and try to make their way in the world. Their parents will harass and chase their independent offspring out of their territory only for these birds to move further afield and be challenged by other territory-holding adults. The juvenile birds are thus invariably forced outside of protected areas and come into conflict with farmers who persecute them in defence of their poultry and livestock. It will be four years before the immature attains adult plumage and looks for a mate in a vacant territory.
Other eagles frequently seen in the vicinity of Angama Mara include the Bateleur, Brown Snake-eagle, Black-chested Snake-Eagle, Tawny Eagle, Long-crested Eagle and – in the forested ravines above the Oloololo Escarpment – the mighty African Crowned Eagle.
Author: Duncan Butchart