Globally eagles are considered as symbols of freedom, courage and strength. Man has admired these powerful predators, proudly displaying them on emblems and flags of many nations.
Yet ironically, despite the evident admiration, man has victimized eagles and other birds of prey over the years. This torment has developed and continued through a sad lack of understanding of the habits of these predatory birds.
Although southern African countries have many nature reserves, these havens are often too small to incorporate the full ranges of the larger eagle species within its boundaries, resulting in them having to extend their range into privately owned land where long term survival is dependent on mankind. To a farmer stocking sheep or goats, the presence of a large predatory bird may seem unwelcome but in fact this should not be the case. Eagles assist in the control of pests and problematic animals and for this reason they should be carefully conserved by farmers who must be educated to work with these majestic birds.
If one studies the food pyramid topped by predators, they assist in the population control of their prey. Although herbivorous animals, such as rock rabbits, are mainly determined by the food availability, the removal of their natural predator would result in a fast growing population explosion. This would be extremely detrimental to stock farmers whose animals would need to compete with the grass eating animals for grazing purposes. These rock rabbits form the predominant diet of the Black, Martial and Crowned Eagles. It is true that these larger eagles sometimes prey on young or sick domestic stock however this is only a small fraction of their diet. A farmer needs to weigh up the stock losses in proportion to the controlling of a pest population. For example a pair of Black Eagles together with their nestlings, require up to 360 rock rabbits annually. These rock rabbits in turn would devour enough vegetation for the support of approximately 23 sheep. In addition, the mere presence of the eagles would deter the rock rabbits to leave their shelters and venture onto the grass plains were they would be exposed to attack.
Mongooses and other small rodents are associated with the spread of rabies, a disease both harmful to man and animal. The Bateleur, Martial and African Hawk suppress this population as they form an important diet requirement for these predators therefore indirectly creating an effective control and spread of the disease. Smaller predators will also control rats and mice. Crowned Eagles assist in controlling monkeys which become a pest in fruit orchards. With the presence of the eagles, they will seldom venture out of thick bush. Vultures are useful for their ability of ‘cleaning up’ by the clearing of any rotten carcasses in the area. The Bateleur and Tawny Eagles are also classified as smaller scavenging birds that play an important role in the system.
In order for farmers to protect against stock losses, they need to ensure that overgrazing does not take place. This would result in the loss of habitat of a wide range of smaller animals that form the natural prey of the predators thus enticing the eagles to switch and prey on young small stock. Another tip would be to locate lambing herds near the farmstead and not in the vicinity of active eagle nesting sites.
Many farmers are now appreciating the valuable role that the predators play in the ecosystem and are attempting to encourage them to return to the area. The presence of a resident pair of eagles in the area is a sign of a stable environment. There are two basic requirements that a breeding pair of eagles must have – undisturbed nesting site and a regular and reliable food source. Eagles also range over several farms therefore it is important to get the necessary understanding and co-operation of all the farmers in the area. Baiting of animals using poisons is irresponsible as this will attract and kill many scavenger birds other than the targeted species. Educate farmers by highlighting the vital role that birds of prey play in assisting with pest control and that they need to co-exist with modern farming practices.
Some important characteristic of eagles:
• The have very few natural predators and may live for 20 to 30 years.
• They have a slow breeding rate
• They build large nests in trees or rocky cliffs often using the same nest for many years
• On average only 25% of young eagles survive their first year and only half of that will reach adulthood and rear their own young
• Generally there is one nesting per year and in the case where 2 eggs are laid, the stronger chick often kills its sibling
• Once it has left the nest, the youngster is forced out of its parents region
Looking at the above points, it is important to understand that if the balance is disturbed by unnatural mortalities such as shooting or poisoning, the population may hastily decline or simply cease to exist. The disappearance of these birds can eventually contribute to severe environmental problems which no farmer would want to endure.