by Asher Collins
1. Extended Family
Vultures are divided into two families, old world and new world. Old world vultures occupy the continents of Europe, Asia and Africa whilst new world vultures are found exclusively in the Americas. Whilst the two groups appear very similar they are actually not very closely related genetically. We call this convergent evolution; two different lineages have converged on a set of similar traits.
2. Not pretty but pretty useful
It’s often said that vultures have bald heads to avoid their feathers becoming dirty whilst they feed. Scientific research, however, suggests this is not the case. A paper1 by Jennifer Ward and her colleagues from the University of Glasgow suggests vultures may be among the less feathered birds in an effort to regulate their temperature. While parts of Africa often reach temperatures of a scorching 400C on the ground, up at 2000m where the vultures fly it can easily be below freezing. By hunching their necks when it is cold and extending them in the heat a staggering 50% reduction in heat loss can be achieved. ‘That's a really valuable energy saving for a scavenging bird that may spend many days without food,’ says Dominic McCafferty, a co-author of the paper.
3. Strong Stomachs
How can a vulture ingest pathogens such as anthrax, botulism or even cholera and not feel any ill effects? The secret lies in the strength of their stomach acid, it is between 10 and 100 times stronger than the stuff that sloshes around in us humans and can kill even the hardiest of germs. The stomach of a Lammergeier can even digest bone. If you think this sounds a bit grim be sure never to surprise a vulture, if startled they have a habit of vomiting in an effort to confuse or even temporarily blind any potential predators.
4. Sensitive Creatures
New world vultures are a rarity among raptors in having a highly developed sense of smell. A Turkey Vulture, for example, can detect a few molecules of rotting flesh in a billion particles of air. That’s more sensitive than sharks, which are famed for their ability to detect minute amounts of blood.
Old world vultures however, have a poor sense of smell, but excellent vision. A meter wide carcass can be spotted from up to four miles away on the open plains. To put that into perspective for a human standing on the ground the horizon is never more than 3.1 miles away.
The Turkey Vulture is the only vulture known to have both a good sense of smell and eyesight, a paper 2 by Gary Graves, an ornithologist at the Smithsonian’s National Museum of Natural History has revealed. It is not known why the bird needs both of these amazing senses.
5. Big Eaters
It may be thought that most of the meat in Africa would be consumed by the big cats of the plains: lions, cheetahs and leopards, but this isn’t the case as Simon Thomsett, a conservationist, points out- "The [mammalian] carnivores can consume only some 36% and the rest is available to vultures. Bacteria and maggots compete with vultures for this resource, but vultures remain the largest consumers.” In fact vultures have been recorded eating one fifth of their body weight in a single sitting. That’s the weight equivalent of me sitting down and eating 250 mars bars!
6. Agents Undercover?
Bizarrely in 2011 a griffon vulture was detained by officials in Saudi Arabia under accusation of spying for Israel. The confusion had arisen over the birds GPS tracking system which was mistaken for a recording device. Thankfully the bird was later repatriated unharmed by UN peace keepers.
7. Keep it Clean
Every year over 40 million tonnes of biomass are left on the African Serengeti in the form of dead herbivores. If left to rot this would become a breeding ground for disease and would eventually threaten the numbers of some of the plains’ more celebrated wild life. By removing this the vultures almost act as the ‘Doctors of the Serengeti’ reducing the spread of illness and keeping the other animals healthy.
8. The Tool for the Job
Few animals have been observed using tools, even less of them birds, but the Egyptian Vulture is in this elite group. Seen in the wild selecting and lifting rocks to use as hammers to break into ostrich eggs the bird proves its ingenuity. As you can imagine an ostrich egg takes a fair bit of cracking and it would be impossible without a tool (see video below).
9. Bones Away!
The bearded vulture or lammergeier has the most unusual diet of any vulture consisting almost entirely of bone marrow. Whilst bone marrow is much prized by animals for its nutritional value it is very hard to get at, being sealed inside tough bone. The lammergeier has devised an ingenious method of reaching this prize, it selects a bone and flies with it up to heights between 50 and 150 meters and takes aim on a flat rocky patch of ground. The lammergeier then lets go and the bone tumbles to the ground hopefully amassing enough speed to crack and reveal the marrow. Amazingly this can be done with bones of up to 4kg almost half the bird’s body weight.
10. Diclofenac Disaster
Diclofenac is a drug used to treat pain and inflammation in cattle. Whilst it is not poisonous to humans or cattle it is incredibly dangerous if ingested by vultures, a dose of under a milligram will cause rapid, lethal kidney failure in even an adult griffon vulture. Amounts as small as that can easily be exceeded if vultures feed on the carcass of a cow that has been treated with diclofenac. The use of this drug in India caused the fastest ever collapse of a bird population4 : in south Asia as a whole it wiped out 99% of the population during the 90s5.
The damage done by this is twofold: first there is the drop in biodiversity caused by the loss of vultures, but there is also an increase in diseases that can potentially be transmitted to humans. I already mentioned how vultures remove pathogens from the environment with their incredible stomachs, once vultures are reduced wild dogs and rats fill in their place as the dominant scavengers. These animals actually spread disease rather than removing it in the way a vulture can; this has resulted in a cost to the Indian economy of 25 billion USD as of 20154.
So what can we do? Well thanks to tireless campaigning the use of diclofenac has been banned in most of south Asia and vulture numbers are beginning to recover. Worryingly however the drug is being used in Europe including Spain (home to 95% of Europe’s vultures) despite there being a vulture and human safe alternative called meloxicam. If you want to help bring about a ban on diclofenac before we see a repeat of the situation in south Asia here in Europe then retweet this article using #banvetdiclofenac , or follow the link bellow.