Restoring the Ñandú Population in Patagonia National Park

Foto: Marcelo Mascareño

Ñandú

Rhea pennata pennata

In Chile’s Aysén Region, the ñandú can only be found in two areas: Ñirehuao, roughly 60 miles north of Coyhaique, and in the Chacabuco Valley, which now forms part of Patagonia National Park. A large sheep farm operated in the valley until 2008, which meant that for more than a century, a population of 20 ñandúes were isolated due to extensive fencing, putting them at higher risk of extinction.

To reverse this trend, in 2014, we began a Ñandú Conservation and Restoration program, establishing Puesto Ñandú to protect this species and begin a monitoring effort to identify threats and natural predators, and to increase our knowledge of the population in this area. At the end of that same year, a police patrol along the Baker border crossing found and rescued two orphaned ñandú chicks. These chicks were the first to become part of the Ñandú Reproduction Center, which was founded in accordance with Chile’s Hunting Laws.

This center is the first of its kind in Aysén. Its main objectives are: to avoid the local extinction of the ñandú and increase its distribution in Patagonia National Park; to develop a monitoring system of the species’ wild population and use this to carry out an annual census and registration of individual birds, nests, and broods; and to support the study of ñandú population trends over time. This situates our conservation efforts within the wild population, using captive handling and release techniques to strengthen the species population overall.

The reproduction center includes two nurseries with a team of specialized wildlife keepers, alongside volunteers and interns. In addition to this, 15 camera traps have been installed, and 6 wild ñandúes have been collared with radio collars.

In March of 2015, 10 chicks with a genetic base from the Magallanes Region joined the reproduction center from a commercial breeder. The chicks were brought by light aircraft, a first-of-its-kind effort, and became the nucleus of the center’s population. Later, near the end of 2015, four more orphaned chicks were also rescued by local police and incorporated into the initiative.

Species characteristics

The ñandú is a member of the ratites (Struthioniformes), a group of flightless birds that includes the ostrich, the emu, and the kiwi. Its species includes three subspecies: the ñandú (Rhea pennata pennata), the suri (Rhea pennata taracensis), and the cordilleran ñandú (Rhea pennata garleppi), the first two of which can be found in Chile.

The ñandú is the largest bird native to Chile, and is characterized by its running prowess, reaching speeds of up to roughly 45 miles per hour. Its neck and legs are very long, with ample plumage reaching down to its ankles. It has only three toes, unlike most birds, and its head and neck are a pale grayish-brown.

Distribution and habitat

Though the ñandú can still be found in many areas of Patagonia, the species has exhibited a general trend toward population decline. The species has a large presence in the Argentinean pampas, and is less frequently spotted in the steppes of the Chilean Patagonia. In the Magallanes Region of Chile, ñandúes can be found in Torres del Paine National Park and Pali Aike National Park, as well as in some nearby fish farming areas. In 1936, ñandúes were introduced in Tierra del Fuego, but have since been eradicated, with the last sighting in 1981.

In the Aysén Region, the ñandú’s geographic distribution is currently limited to two populations. First, there are approximately 300 wild ñandúes at the Baño Nuevo Estate in the Ñirehuao River area (around 30 miles northeast of Coyhaique), where the main activity is livestock farming. Second, there is a population in the Chacabuco Valley near the Baker border crossing, around 40 miles south of Chile Chico.

The ñandú is typically found in areas with rolling hills and plains, but can also be found in foothills, ridges, and plateaus.

Lifecycle

The ñandú has a complex reproductive system that combines polygyny with polyandry,
in which the males build the nests, incubate the eggs, and care for the chicks until the bird reaches the adolescent stage.

The mating season is between September and December. During this period, a male
mates with several females. These females lay their eggs––20 per female, on average––in
a nest built by the male. The males incubate the eggs for 40 days and the chicks
are born between January and February. The young, referred to as “charos” locally, are born with a yellowish-white plumage featuring stripes.

Main food sources

The ñandú is omnivorous. Its principal diet consists of grass, herbaceous plants, and leaves from bushes, along with seeds and insects.

Threats

Historically, one key factor in the ñandú’s population decline has been hunting, along with the harvesting of eggs for human consumption. Other important factors include dogs, fences, human development––particularly due to the livestock, oil, and mining industries––in addition to extreme climate phenomena.

Common name
Ñandú, Ñandú del Sur, Choique, Darwin’s Rhea, Lesser Rhea

Scientific name
Rhea pennata pennata

Conservation status
Endangered (EN), by Chile’s Species Classification System, since 2017, in the Aysén Region
Least Concern (LC), by the IUCN’s red list, since 2016, due to the existence of large populations in Argentina