Tawny Eagle
Created | Updated Feb 10, 2013
Tawny Eagle
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!"
Time for another bird. This is a watercolour painting of a Tawny Eagle, Aquila rapax. This is a fairly large eagle, but not as large and powerful as the Martial Eagle. It reaches 75 cm/30” in length, a wingspan of 190 cm/75”, and a weight of 2.5 kg/5.5 lbs. It is one of the eagles most commonly seen in Africa, although because it is not one of the more striking species, it is not frequently identified correctly. I’ve seen people confuse it with Brown Snake Eagles and it is quite frequently mistaken for the larger migratory Steppe Eagle, Aquila nipalensis. Compared to snake eagles, this one has a longer head, duller, less strikingly yellow eyes, an overall larger, longer body, and feathers going down over its lower legs right to the feet. The easiest way to distinguish it from the Steppe Eagle is by the corner of its mouth, which goes to just below its eye. In the Steppe Eagle the corner of the mouth goes backward to behind the eye, giving it a huge gape. Tawny eagles always have tawny or light brown in their plumage, sometimes streaked with dark, but they are never entirely dark brown. The lightest ones can be a creamy pale brown, but are much bigger than the light brown form of Wahlberg’s Eagle, Aquila wahlbergi, which is also typically found in denser woodland.
The scientific name of this eagle, rapax, means ‘rapacious’. It is a very opportunistic species. While it frequently catches its own prey it also eats carrion, or steals food from other species. It often feeds on roadkill. If it comes across carcasses in the bush it can use its size and strength to chase vultures or even jackals away, but if it isn’t very hungry will feed peacefully alongside them. Back when people hunted more it often sought them out, and snatched away wounded birds. Also in more rural areas it will stay around villages to eat offal and edible scraps the people throw out. It will steal food from many different kinds of predatory birds, even big ones like Martial Eagles and Secretary Birds. It will typically harass these until they drop their prey, which it will then swiftly snatch. At other times it will exploit any lapse in vigilance by another bird-of-prey to dash in and steal its meal.
When hunting for itself, it might either sit on a high perch and spy out the landscape below, or soar and watch from above. While it prefers to swoop onto ground-based prey, it can catch other birds in the air as well, stooping down on them like a falcon. It catches birds ranging in size from doves to young ostriches, preferring mid-sized ground birds like partridges, and will sometimes prowl around the nesting sites of herons and egrets, grabbing unattended chicks. Mammal prey ranges from mice to baby warthogs or the young of small antelopes; most of the time it preys on medium-sized rodents or small carnivores like Mongooses. It has been found feeding on nocturnal mammals like Genets and Spring Hares which means it might occasionally hunt at night, perhaps when the moon is out. It will also prey on lizards and snakes, frogs, and insects such as termites and grasshoppers. It has been recorded catching a catfish by wading into shallow water and grabbing it, rather than by swooping down and snatching it from the water like an African Fish Eagle. It has even been seen feeding on fallen fruit of the Baobab Tree.
This is one of several large eagle species where the chicks practice Cainism. While typically the female will lay two eggs, there is a break of a couple of days between them; the chick hatching first has a size and strength advantage over its sibling, and typically attacks it as soon as it hatches. This is relentless and continues until the younger chick dies, which is usually within a day or two. Sometimes the mother may eat the dead chick or feed it to the other one. But there have been cases recorded where both chicks survived and were raised to adulthood, although the firstborn always remained dominant. The function of this Cainism is probably that the second egg is laid as an insurance policy if for any reason the first chick shouldn’t survive; but if the first chick does survive until the hatching of the second, it conserves resources by killing its sibling; then its parents only need to provide food for one, rather than two. The parents are by all accounts loving and caring to the surviving chick; the female stays with it for about two weeks to brood and shade it while the male brings food to them both. Later she will leave alone it for increasingly longer periods. The chick fledges at the age of about 70 days, but stays near the nest for another six weeks or so. Eagles making it to adulthood can survive for decades; we still don’t know exactly how long they live, but it might be forty years or more.
Tawny eagles are very widespread, occurring in most of sub-Saharan Africa as well as Eastern Europe to Northern Asia as far as Russia and Mongolia, and southward down to India. They avoid the driest deserts and dense forests, but are found pretty much everywhere in between, preferring open hunting regions affording wide views. They have large ranges, a pair defending up to a hundred square kilometres/ twenty-five square miles, and so occur at fairly low densities, but because of their total distribution being so wide, they are currently fairly secure.
