ByMelanie Haiken
Published January 4, 2024
• 10 min read
From lappet-faced vultures with nine-foot wingspans to long-crested eagles with spiky mohawks, Africa’s raptors are undeniably spectacular birds. But these predators are fast disappearing from the skies, according to new research showing an 88-percent overall decline in the raptor population across the continent.
Out of the 42 species of savanna predators and scavengers included in the study, 90 percent experienced decreases, and more than two thirds met the criteria to qualify as globally threatened. (Why we need to save vultures.)
The study, published this week in Nature Ecology & Evolution, uses computer modeling to estimate trends in abundance in four regions over 40 years. Bringing together the work of dozens of researchers working in West, Central, East, and southern Africa, the study reveals widespread but varying population losses, with the most severe occuring in West Africa. In all areas, the largest raptors, such as vultures and eagles, suffered the most precipitous drops.
Native African species have declined severely, such as the Augur buzzard, at 78 percent; Beaudouin’s snake-eagle, at 83 percent; and Rüppell’s vulture, at 97 percent. Once a very common bird, there are now about 22,000 of these vultures left on Earth.
“I used to be able to walk out the door and put my head up and see a bird of prey. Not every minute maybe, but within 10 or 15 minutes you would surely see an eagle or a vulture,” says Darcy Ogada, Africa program director for the Boise, Idaho-based nonprofit Peregrine Fund, one of the study’s two lead authors. “These days I could stand out there for hours.”
The losses, mostly driven by habitat destruction on the rapidly urbanizing continent, could prove catastrophic to ecosystem health. For instance, many vultures and eagles are scavengers that remove 70 percent of the carcasses from the continent each year.
Second lead author Philip Shaw, honorary research fellow at the University of St. Andrewsʻ Centre for Biological Diversity in Scotland, points to the native bateleur eagle to illustrate the depth of the loss.
“It’s very colorful with this bright red beak, and itʻs an amazing flier because it has almost no tail, so thereʻs no drag,” Shaw says. “It’s really a one-off species, there’s nothing else like them.” Bateleur numbers decreased by 87 percent, the study found, and the International Union for the Conservation of Nature recently deemed them endangered.
He remembers visiting Zimbabwe’s Hwange National Park in the 1990s and counting dozens of bateleurs. “In 2019 we visited again and we sat in the same blind for a couple of days and didnʻt see a single one,” he says.
Eyes on the road
While raptors living in protected areas, such as national parks and game reserves, are faring better, the study found major drops there, too. Seventeen—or 40 percent—of the studied species have dwindled even within protected areas.
“A lot of our large eagles and vultures are facing a double jeopardy, where they’re declining at a really steep rate and theyʻre also being more and more confined to protected areas,” says Ogada, who is a National Geographic Explorer. “They’re territorial and these are small spaces, so you only have a finite number that the area can support.”
The large distances between protected areas could cut raptor populations off from each other as on a series of islands, notes Shaw, who is also a National Explorer. “Many of the raptor species would become more and more isolated and populations would become smaller, further apart, and less able to interchange genetically.”
By incorporating the data of so many researchers across such a large geographical area, the study offers a convincing wake-up call, says ornithologist Ian Newton, a professor at the U.K. Centre for Ecology and Hydrology, a nonprofit research institute in London.
“This is the most complete picture we’ve had to date in one study. It really establishes that this downward spread is widespread across a wide area of Africa.” (See beautiful pictures of the world’s eagles.)
Newton, who wasn’t involved in the research. also noted that the study’s methodology of spotting birds via road surveys makes the research very reliable. Typically used to count larger and more conspicuous birds, such surveys are conducted by teams of two to three researchers following established routes. While the driver concentrates on the road and the area in front of the car, other researchers cover the sides, with the count continuing from wakeup time to dusk.
“One of the advantages of this method is that you can cover hundreds or thousands of miles over a period of days and the other advantage is that other people who might come along in 10 or 20 years can do exactly the same thing,” Newton says.
A cascade of consequences
The causes of the declines are many and varied, but most trace back to Africaʻs exponential population growth and its drastic effects on land use. Since the first raptor surveys in the 1970s, Africa’s population has more than doubled. With the population projected to double again by 2058, those trends will only accelerate.
Raptors are also dying in large numbers from trapping, electrocution by the continent’s rapidly spreading network of power lines, and poisoning—both accidental and deliberate. (Learn how Africans are fighting vulture poisoning.)
“Agricultural poisons like pesticides are much more available than they were 40 or 50 years ago, and people use these poisons to kill predators like lions that are getting their livestock,” says Newton. The farmers lure the lions with a poisoned carcass, but the vultures are often attracted as well, gathering in groups of 30 or more.
Poachers use the same method, including in wildlife reserves, to kill off vultures that may give away their presence. (Read more about how poison is a growing threat to Africa’s wildlife.)
Natural recyclers
And when we lose raptors, we lose a whole host of ecosystem benefits.
“They’re actually very beneficial in agriculture because they’re eating rodents, insects, a lot of things that farmers would describe as pests,” Ogada says. Some of the African raptors experiencing serious declines, such as scissor-tail kites, are known for picking off crop-decimating locusts and other flying insects.
These avian garbage collectors are also a crucial link in disease prevention.
Vultures arrive at a carcass within hours of an animal’s death, Newton says. “If that animal was diseased in some way, they would eliminate the disease before it could spread, and that’s an important service that we appreciate now more than ever.”
Studies have backed this up, showing a top-down cycle of consequences called a trophic cascade. In India, the drug diclofenac, given to cattle as an anti-inflammatory, all but wiped out vultures. Birds that scavenged dead cattle ingested the drug, which caused kidney failure. As a result, carcasses piled up, spiking feral dog populations and worsening water quality, ultimately leading to an increase in rabies and other diseases—effects Ogada worries may be repeated in Africa. India now has the highest incidence of rabies in the world, at 18,000 to 20,000 cases a year.
In Africa, solutions include banning poisons, making design changes to power lines, and setting aside more land in protected reserves—changes that have restored raptor populations elsewhere in the world. Currently just 14 percent of Africa’s land mass is set aside for wildlife.
“You can look back and see the trajectories in America and Europe, where there were really severe declines followed by preservation efforts from the ‘70s on, and now you see a lot more birds,” Ogada says.
“Here, sadly, we’re still on the downwards trajectory. Hopefully weʻll start to turn it around, but weʻre not at that stage yet.”
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