On the first Saturday in September each year the International Union for the Conservation of Nature (IUCN) Vulture Specialist group co-ordinates International Vulture Awareness Day. There are currently 23 species of vulture occurring on all continents except Antarctica and Australia. Unfortunately due to multiple anthropogenic threats and a bad reputation the majority of species are listed as Critically Endangered. Vultures have become the most threatened group of terrestrial migratory birds on the planet.
There are two groups of vultures in the world: ‘old world’ and ‘new world’ vultures. The new world vultures are found in North and South America and the old world vultures in Africa, Asia and Europe. Amazingly these two groups are not closely related; the resemblances arose by convergent evolution. This is where two separate linages evolve in isolation to have similar traits, another example would be the convergent evolution of flight in birds and bats, both showing the same function but evolving differently.
One big difference between old and new world vultures is that old world vultures depend on sight to find food whereas many new world vultures have a very good sense of smell (which is unusual for birds) and can smell dead animals from a distance of up to two kilometres. Both groups of vultures are scavengers, mostly feeding on carcasses of dead animals. Their gastric acid is extremely corrosive, allowing vultures to easily digest rotting carcasses infested with many potentially dangerous bacteria. Another adaptation to this feeding habit is the bald head of which vultures are known for. Feathers on the head would be destroyed when the birds enter their heads into the fresh carcasses, and so vultures have lost these feathers.
For many people, the necrophagous behaviour of vultures is very unattractive. However, this is the exact trait which makes vultures such important ecological engineers. As consumers of dead animals, vultures prevent the spreading of diseases such as anthrax and rabies in both wild and domestic animals, and pathogenic risks to humans. The vital function vultures play in the environment is the reason that on this day we want to raise awareness to the fact that vulture populations across the globe are in trouble and need our help.
Why are the world’s vulture species in trouble? All populations are facing threats such as illegal poisoning, lack of food availability and collisions at wind farms and power-lines are putting the recovery of many populations at risk. By far the biggest threat to vulture populations is poison. Whether or not vultures are the intended target for the poisoning, many populations are been hit hard as the carcasses they feast on have become death traps for the vultures.
Moreover, the practice of poising the carcasses of livestock has a major impact on vulture populations and many other carnivores. Local farmers put poison in their dead animals to target large carnivores such as bears, wolves, foxes and stray dogs. This is in retaliation or fear that these animals are killing their livestock and harming their livelihoods. For example between the year 2000 and 2016 in Greece a total of 1015 poisoning incidents were recorded in rural areas causing the death of 3248 animals, a large majority of which were avian scavengers such as vultures.
Perhaps a more saddening case is the use of sentinel poising in Asia and Africa used to intentionally kill vultures. Poachers wishing to prevent detection of their illegal killing of elephants, tigers and other large game animals are deliberately poisoning the carcasses of the poached animals to destroy large numbers of vultures whose soaring behaviour can indicate the location of such activities to alert enforcement officials. In this case vultures are being prosecuted for showcasing their natural behaviours for a devastating reason.
Moving on, vultures are also being effected unintentionally with secondary poisoning. Non-steroidal anti-inflammatory drugs and other veterinary medicines used on livestock are highly toxic to vultures. This means that when the vultures feed from the carcass they soon die from these toxic chemicals. The same fate can be caused by lead residues in carcasses and gut-piles from ammunition used by hunters or livestock owners to kill animals. These two problems inadvertently poisoned around 40 million vultures across Asia, causing populations to plummet.
Unfortunately, poisoning is not the only threat vultures are facing in the modern world. Human infrastructure poses many dangers to these avian species. Vultures are at risk of being electrocuted when perching, roosting or nesting on unsafe energy infrastructure, particularly power distribution poles. Vultures also suffer from collisions with energy infrastructure such as power-lines and wind turbines. Poorly planned and located infrastructure can impose substantial impacts to vulture populations.
Other threats to vulture populations include the direct killing of individuals for the use of vulture heads in ‘traditional’ Chinese medicines and habitat degradation due to vast urbanisation across their range. Broad-scale ecosystem degradation and more localised impacts such as loss of nest trees and roosting sites leaves vultures little space to act naturally. Decline of food availability is also an issue with a reduction in appropriate levels of safe food to sustain healthy vulture populations. The reduction of the earths mega-fauna means there is very little natural food left for vultures, meaning they have to rely more heavily on humans livestock, which as we know can be extremely toxic to the vultures.
Vulture populations across the world are in rapid decline. Populations of three of India’s commonest griffon vultures have declined by more than 90% during the last decade. Fortunately many organisations across the world are doing what they can to try and turn the tide for vulture species. In India ZSL has participated in getting legislation put into place to ban farmers from using certain medicines for their cattle. The Balkan Vulture project have developed national anti-poison road maps which highlight key areas for their vulture populations.
Again in Niger, vulture awareness campaigns are being used for the public. The idea is to raise awareness at the local, regional and national levels in Niger about the decline of vulture populations and their important role as scavengers and providers of ecosystem services. Conservation breeding programmes have been established in India, Nepal and Pakistan and, since 2009, all three of the most affected vulture species in the area have been breeding successfully and in genetically diverse and viable numbers. These public awareness programmes coupled with captive breeding programmes give hope that vultures may still have a place in our modern world.
Recent studies of the movement of vultures using satellite telemetry have shown the vast cyclical movements undertaken by this group of species. Accordingly, conservation actions can only be effective if implemented at the flyway level, which requires a broad approach and the engagement all countries holding vulture populations. Much work is needed to halt current population declines and conservation management guidelines need to be followed for all species in order to tackle declines. Work must take place not just with the vultures but with the humans that are causing these vultures to decline.
Vultures are another of our planets species that are suffering at the hand of human development. As humans spread destruction across the natural world, it is the fauna and flora of the areas that suffer. Vultures are a prime example, just like sharks, that have been given an image of death. Movies and stories give humans the perception that vultures are evil dirty creatures. This couldn’t be further from the truth. Vultures are key components to the circle of life, without them many ecosystems will suffer, and so will the humans that depend on those ecosystems. Conservationists use days like today’s vulture day to raise awareness for different species, but we need to spread awareness and discuss the plight of our planets species every day. We are the ones causing the destruction, and we are the only ones who can stop it from spreading and save animals like the vultures.