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Conservationists restore extinct antelope to Sahel grasslands
In 2012, biologists Marie Petretto and John Newby surveyed Chad's Ouadi Rimé-Ouadi Achim Faunal Reserve, a protected expanse larger than Ireland, to assess its potential for reintroducing the scimitar-horned oryx. The species, declared extinct in the wild during the 1980s, had survived only in captivity. Their mission marked the beginning of an ambitious effort to revive one of the few large mammals ever brought back from extinction.
The Sahel's hidden diversity
At first glance, the reserve appears barren-a sun-scorched landscape where temperatures often exceed 50°C (122°F). Yet Petretto, a wildlife veterinarian, discovered a surprising variety of ecosystems. Acacia trees dotted the terrain, offering shade akin to "umbrellas on a beach," while seasonal river valleys, or wadis, transformed into lush corridors during monsoon rains. These pockets of life, sustained by wild bitter melon and shrubs, convinced the team that the reserve could support the oryx's return.
The scimitar-horned oryx, named for its sweeping, sword-like horns, evolved to thrive in such harsh conditions. Standing over a meter tall at the shoulder, the antelope can survive months without water, relying on moisture from plants and a physiological adaptation that allows its body temperature to rise to 46°C (115°F) without sweating.
From zoos to the wild: A global breeding effort
The oryx's decline was rapid. Once roaming from the Nile to the Atlantic, the species vanished from the wild due to overhunting-accelerated by the introduction of 4x4 vehicles and automatic weapons. By the 1980s, only captive populations remained, scattered across zoos and private collections. Conservationists launched a coordinated breeding program to prevent inbreeding and preserve genetic diversity.
Marwell Wildlife, a UK-based conservation charity, played a pivotal role. Its 400-acre estate in Hampshire became a hub for the species, housing a herd that now mingles with zebras and rhinos. Tania Gilbert, Marwell's head of conservation science, explains that the oryx's social hierarchy is established through horn-clashing displays, though one young male, Conor, has taken his confidence further-challenging a rhino to back down.
The studbook for the species, managed by Marwell zoologist Sophie Whitemore, functions like a "Tinder for endangered species," tracking bloodlines to ensure healthy pairings. From fewer than 50 individuals in the 1960s, the global captive population has grown to over 3,295 across 182 institutions. An additional 10,000 oryx exist on private ranches in the U.S., primarily in Texas, though these are not part of the controlled breeding program.
Reintroductions and ecological impact
The first reintroduction attempt occurred in 1985 at Tunisia's Bou Hedma National Park, where 10 oryx from Marwell and Edinburgh Zoo were released into a fenced area. The experiment succeeded, with the herd thriving for decades. Similar projects followed in Morocco and Tunisia, where oryx were reintroduced alongside dorcas gazelles and North African ostriches. These efforts demonstrated the species' resilience and provided lessons for larger-scale releases.
In 2016, the first 25 oryx were flown to Chad's Ouadi Rimé-Ouadi Achim reserve. Satellite collars revealed their rapid adaptation to the reserve's three distinct seasons-hot-dry, rainy, and cool-dry. By 2023, the wild population had grown to between 550 and 600, prompting the IUCN to downgrade the species' status from "extinct in the wild" to "endangered."
Beyond their symbolic success, oryx may help combat desertification. A study on the closely related Arabian oryx found that seeds excreted by the animals were 250 times more likely to germinate, aiding vegetation growth. Tim Woodfine of Sahara Conservation notes that oryx distribute seeds and recycle nutrients during their migrations, which once spanned up to 1,300 km (808 miles). Their presence could bolster ecosystem resilience, providing prey for predators like cheetahs and African wolves.
Challenges ahead
Despite progress, the oryx's future remains tied to human behavior. Abdulaziz Ben Mohamed, a retired Tunisian wildlife official, highlights the dual threats of poaching and climate change. While locals celebrate the oryx's return, droughts have reduced rainfall in reintroduction sites like Dghoumes, threatening habitat recovery.
The Sahara has expanded by 10% over the past century, encroaching at a rate of 7,600 sq km (2,934 sq miles) annually. The African Great Green Wall Initiative, a pan-African effort to restore degraded lands, aims to mitigate this expansion. Petretto observes that overgrazing by livestock has accelerated desertification, with sand burying villages where vegetation has been stripped bare. Oryx reintroductions, combined with grazing restrictions, have shown promise in reversing this trend.
John Newby emphasizes that the work is far from over. "The first phase has been a success," he says, "but the other nine-tenths of the iceberg depends on human behavior-whether communities can accommodate wildlife as part of their livelihoods."
"They're a key ecological component of ecosystem resilience. Without them, you're missing something fundamental."
Tania Gilbert, Marwell Wildlife
