There are many poisons used by man that affect raptors – the farmers use poison for “problem animals” such as the black-backed jackal, caracal, leopard or cheetah from ravishing their stocks, this causes major problems when scavenging raptors like Bateleurs and vultures eat the bait or poisoned animal. Organochlorine pesticides build up in a food chain and unfortunately many raptors being at the end of that chain, eat the poisoned prey and will most certainly face death. In agricultural pest control Organophosphates have replaced Organochlorines, as they are believed to break down much faster, whereas the Organochlorines remain stable and are stored in the animals fat. Where humans are concerned the organophosphate can be lethal. Insecticides of today, such as parathyroid and carbonates are highly toxic to birds but not to mammals. Secondary poisoning in birds can occur, however, when carbonates are used in the control of termites, as the birds eat termites. Low levels of Organochlorines ingested by raptors over a period of time results in egg breakage, shell thinning and embryos dying in unbroken eggs, thus causing a decline in raptor population and extinction in certain areas. Always use an environmentally product like “Racumin” in the control of rodents.
The basic requirements are a reliable food source and an undisturbed nesting site. Fortunately an increasing number of landowners now protect and preserve their eagles, as they have come to realise the benefits of eagles in their territory. Eagles have an exceptional ecotourism value, as bird watching is one of the fastest growing pastimes in South Africa. Diversity of habitat results in a rich and dense fauna. Mountain populations of black eagles have a higher nest density and breeding success compared to open area populations. At the present time, in this country, there are lengthening lists of
endangered species and degraded ecosystems, which never heal.
The environment must be protected, to prevent extinction of animals and plants.
All raptors are attracted to power lines, as they utilise them for hunting, nesting, roosting and feeding perches. As they are so vulnerable to electrocution these power lines can be hazardous to eagles, if the phase conductors are separated by less then the wingspan of the eagle, the bird can be electrocuted while landing or taking off, or if the distance between an earth-wire and an energised conductor is less than the wingspan or the distance between tip of the bill to tail tip. The eagle’s age, experience, the weather, or season may also affect the susceptibilty of the eagle. Inexperienced eagles may also collide with the conductors in flight, but this risk is lower then electrocution. Landowners are requested to report eagles roosting on lines, plus dead eagles found under the power lines, to assist Eskom in taking steps to minimise electrocutions. Eskom, in association with EWT are world leaders in the development of various products to insulate conductors, thus reducing deaths to sustainable levels.
Black eagles must be one of the most persecuted eagles in the world, due to the fact that some farmers feel justified that they kill small livestock. South African public are now aware, due to various media articles, of the relentless killing of these eagles by stock farmers, for decades. Farmers are now encouraged to tolerate these raptors and accept their beneficial, ecological function in farming ecosystems, particularly in the control of dassies, which compete with livestock for grazing. There is a huge ecological impact to the healthy ecosystem by the killing of raptors.
Removal of eggs and chicks
Eagles are not aggressive to humans unless they themselves or the contents of their nests are threatened. Hand reared eaglets are likely to be more aggressive to humans and
are more difficult to handle than wild ones. Chicks handled by humans are imprinted, which is a serious handicap to successful rearing and then they are unable to return to the wild. Severe damage can be done to a chick if fed on an incorrect diet – damage that is irreversible.