As if out of thin air, vultures begin to fall from the sky like a squadron of untidy planes that have all suddenly lost power. For a few moments, the vultures stand, looking uncertain, wary, unwilling to make the first move. Then one bird makes a break for it and the hushed gathering suddenly becomes a frenzy. While the 160-kilogram (350-pound) waterbuck carcass the birds lurch toward appears big enough to sustain the entire group for days, the vultures seem to know better.
Despite the flying feathers and hair, clouds of dust, and angry squawks, the birds are singularly focused on consuming as much flesh from this carcass as possible. With their sharp, down-curved beaks, they stab into waterbuck flesh.
Left, a white-headed vulture in flight.
These photos originally appeared in bioGraphic, an online magazine featuring beautiful and surprising stories about nature and sustainability.
Once called “Africa’s Eden,” Gorongosa National Park has had a storied and, at times, traumatic past. Established in 1960, the park, which sits near the southern end of Africa’s Rift Valley and covers roughly the same area as the state of Rhode Island, once boasted some of the largest populations of big animals in all of Africa. A 1969 survey tallied more than 2,000 elephants, 14,000 buffalo, and more than 200 lions. By the 1970s, Gorongosa had become Africa’s most popular national park among foreign tourists, attracting the likes of movie stars John Wayne and Joan Crawford, and Apollo astronaut Jim Lovell. But the heyday was short-lived.
A marabou stork, Leptoptilos crumenifer, looks for its next bite as it stands near a white-backed vulture, Gyps africanus, feeding on a waterbuck carcass, Kobus ellipsiprymnus.
In 1977, just two years after Mozambique’s independence from Portugal, the country fell into a state of civil war that would last 16 years. In addition to the countless human atrocities committed during the conflict, warring factions—and the impoverished communities they left in their wake—devastated Mozambique’s wildlife. In 1994, when scientists conducted the first post-war surveys of Gorongosa, they found only remnants of the park’s famous herds. A mere 100 elephants, 15 buffalo, and a handful of zebra remained. Gorongosa’s once-famous lion population had fallen by 80 percent. And those were just the animals anyone bothered to count.
In 2004, although many people had already written Gorongosa off as a catastrophic ecological loss, former tech entrepreneur turned philanthropist Greg Carr was looking for a new challenge and turned his attention to Gorongosa. Carr’s initial pledge of $500,000 toward Gorongosa’s restoration ballooned to $40 million the following year in a 30-year agreement with Mozambique’s Ministry of Tourism to both restore the park’s ecosystems and promote economic development in the region. Since that time, the Gorongosa Restoration Project has managed and studied existing wildlife populations and has begun to restock species struggling to recover on their own.
A young white-headed vulture,Trigonoceps occipitalis, stands on a fresh warthog carcass, perhaps waiting for stronger white-backed vultures to arrive and open it.
Within the relative safety of Gorongosa National Park, vultures find both priceless nesting habitat and growing populations of potential food sources. Unfortunately, these highly mobile birds don’t stay within the park boundaries. Vultures are obligate wanderers, and given the right conditions—thermals that rise vertically over southern Africa’s grasslands and savannas on any given day—they make long-distance travel look easy. Within minutes, a bird can glide beyond the protected parklands, and can cross international borders with only slightly more effort.
When paired with their keen eyesight, this mobility affords vultures access to food sources that most animals would never see or be able to reach. But their wide-ranging habits also expose them to threats that more sedentary species wouldn’t encounter.
A white-backed vulture, Gyps africanus, soars high and far in its search for dead animals. During its long flight, the bird saves energy by catching thermals, or waves of hot air that rise from the ground and provide lift.
Poisons account for more than 60 percent of vulture mortality in Africa. In some cases, the poisoning is incidental, intended for other scavengers such as hyenas or for predators like lions that threaten livestock. Increasingly, though, the poisons are intended specifically for vultures, left by poachers who have learned that the circling birds give away the location of their crimes. In the most deadly of these events, in 2013, a single elephant poached and then laced with poison near Namibia’s Bwabwata National Park killed nearly 600 vultures.
The impact on vulture numbers across the continent has been devastating. All eight species in Africa have seen population declines of at least 70 percent over the past 50 years, and five species have declined by more than 90 percent during that time period.
Satiated white-backed vultures, Gyps africanus, stand around a warthog carcass after much of the meat has been removed from the abdomen.
The efficiency with which vultures can remove flesh from a carcass is legendary. They’re cleaning machines, all but perfectly adapted to feeding on rotting carcasses. And in most ways that’s true. But here, on this parched floodplain in Mozambique’s Gorongosa National Park, these consummate scavengers would have been out of luck had it not been for the three fresh cuts that biologist Jen Guyton made through the waterbuck’s tough hide, giving the birds access to the flesh underneath. Although the vultures’ hooked beaks are sharp enough to pierce the hides of smaller animals, they’re unable to access thick-skinned carcasses like this one without the help of larger scavengers like hyenas and wild dogs—animals still missing from this recovering ecosystem.
It’s an unusual scenario, but Gorongosa is no ordinary place. Its unique history has left the park’s ecosystems oddly unbalanced and incomplete. Yet, given the state of Gorongosa just a decade ago, many view the park as a remarkable conservation success story. And despite the challenge posed by the current lack of some formerly abundant species, Gorongosa and protected areas like it may be the only hope of saving what remains of Africa’s rapidly dwindling vulture populations.
In an effort to design conservation strategies that might slow the plummet of vulture populations across Africa, the Gorongosa Restoration Project recently teamed up with Botha’s Endangered Wildlife Trust and researchers from Boise State University’s Intermountain Bird Observatory.
The goal of this collaboration is to find out where and how the park’s vultures spend their time, how far afield they wander, and what threats they face along the way. Over the past two years, the team has tagged 16 birds—seven white-backed vultures, Gyps africanus, and nine white-headed vultures, both of which are critically endangered species. After capturing the birds and taking measurements and blood samples, the team placed GPS transmitters on the vultures and have been following their movements ever since.
Aspiring scientist Ayla Kaltenecker, Greg Kaltenecker’s 10-year-old daughter, uses calipers to measure the length of this white-backed vulture’s head. A suite of morphometric measurements taken from each bird will help assess important biological variables such as age, sex, and overall health of the animal.
The scientists’ observations have confirmed that many of Gorongosa’s vultures venture far outside the park. The birds travel as much as 160 kilometers (100 miles) a day, and some have been observed as far afield as South Africa, up to 1,600 kilometers (1,000 miles) from Gorongosa. “They’re traveling huge distances, especially the younger ones,” says Greg Kaltenecker, Director of the Intermountain Bird Observatory who is leading the study. “Even though we trap them in Gorongosa, a few weeks later they could be thousands of kilometers away.”
Eventually the birds make their way back, but for researchers like Botha and Kaltenecker, it’s unnerving to consider the countless dangers the vultures—some of the most endangered creatures on the planet—encounter when they’re outside the protective borders of the park.
Metal leg bands, each with a unique code, will help biologists identify birds that are recaptured in the future, or help identify remains if the bird is found dead.
Although vultures have long been taken for granted, even reviled, their recent precipitous declines are motivating many people to take notice—and to help policymakers see what a world without these creatures might look like. Even in Gorongosa, with its relatively healthy populations of vultures, it’s possible to get a glimpse of that world.
Young Mozambican biologist Diolinda Mundoza cradles a juvenile bateleur eagle,Terathopius ecaudatus, before releasing it. Although vultures are the only known obligate scavengers, many other birds like bateleur eagles, fish eagles, and marabou storks are facultative, or opportunistic, scavengers that compete with vultures for food. Biologists from the Intermountain Bird Observatory measure and tag these important raptors as well.
Two warthogs, Phacochoerus africanus, are pushed by a helicopter toward a transport truck through a huge fabric funnel, as workers close curtains behind them so they can't escape. The warthogs will soon start a new life in the southern part of the country, where wildlife populations are still struggling to recover after the war. These wildlife captures are a testament to the success of the park’s restoration: Some species, like these warthogs, are now so abundant that managers are able to send them to other parks to help in their conservation efforts.
What’s clear from this and other research in Gorongosa National Park is that vultures are critical members of this recovering ecosystem, and their relative success here has surely played a role in the overall resilience of the park. Gorongosa, in turn, may be just as critical to the survival of this, the most rapidly declining bird group in the world. Not only does the park provide key nesting habitat, food sources, and safety from persecution, but it’s helping scientists understand the risks vultures face beyond the park’s borders.
Although there’s little that scientists and wildlife managers working in Gorongosa can do to eliminate the threats that any one bird might face outside the protections of the park, the information they gather can be used to inform international agreements around the availability of toxins and other hazards. It also highlights the need to manage ecosystems like those in Gorongosa to benefit not only the charismatic megafauna tourists come to see but the oft-overlooked scavenger, too.
Biologist Teague Scott from the Intermountain Bird Observatory carries a recently captured young white-backed vulture, Gyps africanus, back to the measuring station.