In Patagonia National Park Rewilding Chile is leading efforts to raise and rewild one of South America’s largest birds, the Darwin’s rhea
By Milo Putnam on June 18, 2022
Imagine raising a dozen children. All at once. Completely on your own. Darwin’s Rhea dads live this reality regularly. For these flightless birds, flying solo takes on a whole new meaning when it comes to fatherhood. Wildlife rangers Alejandra Saavedra and Gabriela Muñoz, both with Rewilding Chile, are working to lighten the load for these feathered fathers as they help to bolster wild populations of Darwin’s Rhea in Patagonia National Park, where they have nearly vanished.
Step 1: At the start of the breeding season, male rheas battle over territory for a site to nest and for the attention of females. If their courtship displays— which involves standing upright, elegantly spreading their wings, and moving with a subtle swagger— are successful, they can attract multiple females.
Step 2: Working as a newly formed group, the dominant male and females will collect vegetation and pebbles to create the nest. Eventually, the females will return to lay their eggs in that one shared nest. Over the course of days, these female rheas will typically lay several eggs, totaling about 20 to 25 eggs in the nest.
Step 3: Once all the eggs are laid, the females will leave the rest of the work to the male. All on his own, he’ll protect and incubate the eggs for over a month. Meanwhile, the females will move on to search, mate, and lay eggs with other males.
Step 4: After the incubation period and after the first rhea chick has hatched, their soft noises will encourage the other developing chicks to begin pipping through their own eggs. In just a couple of days, the entire nest of eggs will hatch into vulnerable dark-striped chicks, that will be completely dependent on their fathers to stay warm since their newborn feathers do not provide enough insulation.
Step 5: Using whistle-like calls, the adult male rhea will continue to protect these chicks for the next six months on his own as he teaches them important survival skills for living in the harsh environment of the Patagonian steppe. These fathers take their job very seriously and will even drive away other rheas, including the chicks’ own mothers.
Rhea paternal care takes center stage in Chile’s Patagonia National Park, but the reality is these long-legged birds were nearly extirpated from this high-elevation steppe. The Darwin’s Rhea, known as the Ñandú in Spanish, is found in both Argentina and Chile. Across this species’ range, they have experienced a general population decline. Historically, the rhea’s main threat has been hunting, along with the harvesting of eggs for human consumption.
In the Chacabuco Valley, which now forms part of Patagonia National Park, the landscape was also fragmented by expansive fencing and over-grazed from sheep farming for more than a century. This isolated a population of less than 20 Darwin’s Rheas, putting them at an even greater risk of extirpation within northern Patagonia.
In 2014, Re:wild’s close partner Rewilding Chile began the Ñandú Conservation and Restoration program. Their initial actions focused on having rangers monitor poaching and egg collection while identifying natural predators and researching the population in the area. Toward the end of that same year, a local police patrol found two orphaned rhea chicks. These rescued chicks were the start of what would become the Ñandú Breeding Center, a first-of-its-kind in the region. Later, the center received 12 birds and started incubating eggs collected from the wild. The center aims to prevent the local extinction of Darwin’s Rhea by continuing to monitor the species in the wild and increasing populations with individuals raised in a conservation breeding program.
“Right now, the focus of the project is to establish a population of Darwin’s Rhea in the steppes of Patagonia National Park and achieve a healthy population by having them reproduce themselves in the wild,” says Alejandra Saavedra, wildlife ranger and coordinator of Rewilding Chile’s Ñandú Breeding Center.
This center includes breeding enclosures, acclimation areas, and a pre-release pen that expands over 150 acres (72 hectares). Since the entire compound was constructed within the rhea’s range, native vegetation grows in these areas, which allows the birds to naturally feed, though they still receive supplemental food sources with vitamins and minerals.
But this more natural location isn’t without significant challenges. Operating the center in this isolated mountainous area of Patagonia National Park leaves the facility exposed to severe windstorms and heavy snowfall, in addition to natural predators, such as Puma, Grey Fox, and Culpeo Fox that frequent the area. These risks to little rhea chicks have prompted the team to increase the height of electric fences on the perimeter, strengthening the barriers surrounding these precious birds.
Despite the challenging setting of Chilean Patagonia, these efforts to protect Darwin’s Rhea are so far working. Since these efforts began the wild population of Ñandú has nearly quadrupled from the original 20 individuals to now over 70 wild Darwin’s Rhea in Patagonia National Park.
This rewilding effort helps to strengthen not only the Darwin’s Rhea population within the park but is working to strengthen the entire network of life present in the Andean steppe ecosystems.
“The fact that we have a monitoring area established here, designated to the care and protection of rhea, helps not only the rheas but everyone,” says Saavedra. “All of the living creatures that exist here, even the plants. There is more wildlife now than there was six years ago, and I believe it has a lot to do with the work we have done at the breeding center and the support from all the entities around us. All these actions have helped in one way or another.”
Researchers have observed reintroduced rheas socially interacting with both wild rheas and wild Guanacos – large herbivores closely related to llamas. This behavior is a natural survival strategy between species, as they work together to improve their vigilance for predators, like Puma, within larger mixed-species groups. The Rewilding Chile team has noted this as a significant restoration success considering the ancestral relationship between these two Patagonian species.
The Ñandú Breeding Center is led by two incredible wildlife rangers that ensure these treasured birds are well taken care of. Alejandra Saavedra, the coordinator of the center, studied protected area management and has an extensive background working as a professor, a consultant, and even worked for the Chilean National Forestry Services. Alejandra is a passionate wildlife ranger devoted to the success of the Darwin’s Rhea.
“One does this work because it feels like contributing a grain of sand to help the ecosystems maintain healthy functioning wildlife,” says Saavedra. “So instead of going backward, we move forward and keep generating natural cycles.”
Gabriela Muñoz, a veterinary technician, joined the center as an intern in 2018 and has since become a full-time wildlife ranger focused on rhea. The day-to-day management of the Ñandú Breeding Center falls between these two women. Caring for a growing flock of rheas is no easy feat. With the help of volunteers and interns, they ensure that everything operates smoothly, from preparing diets to checking the electric fence daily.
Preserving Patagonia’s iconic big birds continues year after year with raising young rheas and releasing 10-20 juveniles into the wild as part of an active management strategy to address the local extinction of this species. Since 2015, Darwin’s Rheas have increased their habitat within the park by over 30%, now spanning nearly 10,000 acres (4,000 hectares). Through local support and a network of partners, Rewilding Chile is ensuring that the Darwin Rhea will remain a key part of the Patagonian wilderness.
“I’m so happy,” says Saavedra. “I cannot feel more grateful and happy to see them running in the wild. I wish they could be way more, but we are strengthening their population with these releases every year, we are contributing not only to recovering the rheas, but the entire ecosystem, and its wildlife. So yes, I’m happy. I’m glad to be part of this moment.”
Milo is Re:wild's communications specialist working with our partners to share their stories in protecting and restoring the wild. With over a decade of natural resource interpretation and environmental education experience he lives to spark connections between people and wildlife. Milo loves to travel with his husband and is passionate about supporting ethical wildlife tourism.