VULTURES, critical to Africa’s ecosystems, have always had a bad popular reputation, portrayed as the evil scavengers in the jungle book for example. A reputation that now may have proved fatal.
Unlike rhinos and elephants whose conservation campaigns have dominated headlines across the world, the plight of Africa’s vultures has remained well below the radar – tragically so.
A new letter, published in the Journal of the Society for Conservation Biology, reveals the extent of the damage to vulture populations.
The letter is the first publication of a series of results from a 30-year study across Africa. Findings showed that populations are declining throughout Africa, with West and East Africa showing the greatest declines per annum.
Populations of eight species of vultures that were assessed had declined by an average of 62%, seven had declined at a rate of 80% or more over three generations. Of these, at least six appear to qualify for up-listing to critically endangered on the International Union for Conservation of Nature (IUCN) red list of threatened species.
The most significant threats are poisoning and trade in traditional medicines, which together accounted for 90% of reported deaths. Of 7,819 vulture deaths recorded across 26 countries, 61% were attributed to poisoning, 29% to trade in traditional medicine, 1% to killing for food, and 9% to electrocution or collision with electrical infrastructure.
According to the paper, African vultures are often the unintended victims of poisoning incidents, in which carcasses are baited with highly toxic agricultural pesticides to kill carnivores such as lions, hyenas, and jackals, or to control feral dog populations.
Furthermore, the recent rapid increase in elephant and rhino poaching throughout Africa has led to a substantial increase in vulture mortality, as poachers have turned to poisoning carcasses specifically to eliminate vultures, whose overhead circling might otherwise reveal the poachers’ illicit activities
Since July 2011, there have been at least 10 poisoning incidents that have, collectively, killed at least 1,500 vultures in six southern African countries
The impact of the loss of these animals cannot be under-stated. Vultures provide essential ecosystem services, yet they are among the most threatened groups of birds worldwide.
According to the paper, because vultures suppress the number of mammalian scavengers at carcasses, resulting in fewer contacts between potentially infected individuals, levels of disease transmission are likely to be greater in the absence of vultures.
This was seen in Asia where an Asian Vulture Crisis has resulted in a parallel increase in feral dog populations, which are now the major consumers of carcasses in urban areas in India and also the main reservoir of diseases such as rabies.
The growth in feral dog numbers has, and will continue to, contribute to the risks associated with rabies transmission, both in Africa and in Asia. It is estimated that this has added $34 billion to healthcare costs in India between 1993 and 2006.
Vultures also freely dispose of organic waste in towns. Egyptian Vultures, for example, consumed up to 22% of annual waste in towns on Socotra off the Horn of Africa
Most at risk:
The most rapid declines had occurred in:
Rüppell’s Griffon Vulture
The median decline rates for these four species varied between 5.1% and 6.1% per annum and averaged 4.6% per annum for the eight species assessed. Combined with long generation lengths (of about 16.6 years) and low annual fertility, these declines either meet or exceed the threshold for species qualifying as critically endangered or endangered.
The scientists recommended that national governments urgently enact and enforce legislation to strictly regulate the sale and use of pesticides and poisons, to eliminate the illegal trade in vulture body parts, as food or medicine, and to minimise mortality caused by power lines and wind turbines.