For Argentina’s ruddy-headed goose, threats grow while population shrinks

For Argentina’s ruddy-headed goose, threats grow while population shrinks

  • The ruddy-headed goose is on the brink of extinction, with just 700 birds left in southern Argentina and Chile, the result of hunting in the 20th century and habitat loss in the 21st.
  • Every southern winter, these aquatic birds migrate more than 1,300 kilometers (800 miles) north, alongside the closely related ashy-headed and upland geese, from southern Patagonia to the province of Buenos Aires.
  • A sanctuary in the species’ wintering area, a site specifically for the conservation of the species in the Argentine sector of the island of Tierra del Fuego, and a breeding center in Chile are among the conservation strategies being implemented to save the species.

The photo speaks for itself: a woman lies on the ground with just her smiling face visible, her body covered by about 20 dead geese, the result of a “successful” day of hunting. Although the photo is from the beginning of this century, the consequences of this intensive hunting of the ruddy-headed goose (Chloephaga rebidiceps), among other reasons, are noticeable in the present day: the species is now one of the most threatened in Argentina, to the extent that it’s considered critically endangered on the local list of animals at risk. Most recent counts put the population at no more than 700 individuals.

The status of two other species of this genus are also of concern: the upland goose (C. picta) and the ashy-headed or royal goose (C. poliocephala) are both classified as threatened on the same local list.

A woman poses with about 20 geese killed during a hunt. The photo was taken in Buenos Aires province, prior to a total ban on geese hunting in 2007.

These waterfowl are endemic to South America and similar in appearance to domestic geese, but more closely related to ducks, and they include five species. Three of these species — the upland, ashy-headed and ruddy-headed geese — all share one characteristic: they’re migratory birds. They nest and breed in southern Patagonia, on both sides of the Argentina-Chile border, with most traveling some 1,300 kilometers (800 miles) north in April and May to spend the winter in the provinces of Buenos Aires and Río Negro.

At approximately 50 centimeters (20 inches) long and weighing 2 kilograms (4.4 pounds), the ruddy-headed goose is the smallest of the species. It gets its name from it reddish-brown head, the color of which fades toward the front of its head and at the crown. Its other distinctive features are its black beak, gray belly marked with thin black stripes, and orange legs.

A pair of ruddy-headed geese resting on a cliff. These birds are part of the population found on the Falkland Islands, known in Argentina and the rest of Latin America as the Malvinas. This population is sedentary, with several genetic differences from that on the South American mainland. Image courtesy of Pablo Petracci.

The tiny population of some 700 ruddy-headed geese that survives on the South American mainland contrasts with a non-migratory population of 42,000 that’s permanently settled on the Malvinas, the local name for the U.K.-administered Falkland Islands, to which Argentina also lays claim. Ornithologists Mariana Bulgarella and Cecilia Kopuchian, experts in evolutionary biology, have carried out genetic analysis that shows significant differences between the continental and Malvinas/Falklands geese, suggesting they’re different species. If this is the case, which new studies will need to confirm, it won’t be possible to repopulate the continental species with the Malvinas/Falklands geese.

Due to the size of the Malvinas/Falklands population, the ruddy-headed goose isn’t considered a globally threatened species by the IUCN, the international wildlife conservation authority. In fact, the IUCN Red List puts the species’ conservation status as being of least concern. Experts say this classification is having a negative impact in terms of implementing action and management plans, conducting environmental impact assessments, and obtaining funds for research and conservation work for the continental population that’s at risk of going extinct.

The female upland goose, center, has a reddish head that makes it difficult to distinguish from the ruddy-headed goose, resulting in incidental deaths in Chile where hunting of the upland goose is still permitted. This photo was taken in Coronel Dorrego district, Buenos Aires province.

A plague to eradicate

In 1954, British ornithologist Peter Scott considered the ruddy-headed goose the most common goose species of those found around the northern steppe of the island of Tierra del Fuego, the southernmost tip of the South American continent. However, over the following seven decades, a series of events led to the species’ current dire situation.

Pablo Petracci, a researcher specializing in conservation and management with the Gekko Group at Argentina’s National University of the South, said the population decline “cannot be attributed to one single cause.”

But the root of the issue can be traced back before Scott’s assessment, to 1931, when many rural communities pressured the government to declare the geese a “plague.” Farmers complained of geese entering their wheat fields just as their crops were beginning to grow, and eating the shoots while also degrading the soil with their droppings. Although there was no scientific evidence at the time to support the accusations, the authorities agreed to their request, and rolled out control and eradication plans.

For decades, the indiscriminate hunting of geese was encouraged by authorities due to the belief that the species was hurting wheat and other cereal crops.

This marked the beginning of a period of sustained persecution of the species, which included various actions such as the destruction of eggs (an estimated 180,000 were destroyed between 1972 and 1974), poisoning and hunting. The most dramatic measure was the use of airplanes to shoo the geese out to sea.

Carlos Pardo, the owner of the farm El Tamarisco in San Cayetano, which has been in his family for three generations, explained how this was done in the 1980s and 1990s: farmers would hire planes to startle flocks of geese and send them flying up. They would then effectively herd them, using the planes’ engine noise as a sort of bullwhip, off the coast and out to sea. Although this activity was declared illegal, it continued until 2010. For all the expense and effort, though, it was useless: the birds are robust and aquatic, Petracci said, and would simply return to land after a short time at sea.

Each flock of ruddy-headed geese used to number around 100-200 birds. Flock sizes are now significantly smaller. Image courtesy of Pablo Petracci.

Gray foxes: A deadly enemy

For all the sound and fury of the planes, there was a far deadlier threat cutting down the population of ruddy-headed geese in Argentina and Chile: the introduction of the South American gray fox (Lycalopex griseus) to Tierra del Fuego. Native to the Pampas and Patagonia regions, the species was brought to the island in 1951 to control the population of the invasive European rabbit (Oryctolagus cuniculus), but its presence had a devastating effect on the geese.

Other factors for the species’ decline include overgrazing of their habitat by sheep farming, oil and gas activity, and predation by the American mink (Neovison vison), another introduced species, along with the installation of wind farms on both sides of the Andes.

Other factors for the species’ decline include overgrazing of their habitat by sheep farming, oil and gas activity, and predation by the American mink (Neovison vison), another introduced species, along with the installation of wind farms on both sides of the Andes.

A small marsh serves as the resting place for a group of ruddy-headed geese. Water surfaces are vital and determine the sites where the birds will winter. Image courtesy of Pablo Petracci.

Hunters, both local and foreign, were once among the most serious threats to the species, but became less so following the 2007 ban on hunting migratory geese in Buenos Aires province; the ban was expanded to the whole of Argentina four years later. At that time, naturalist Hernán Ibáñez, who previously worked in the monitoring department of the former National Secretariat of the Environment and now works at the Azara Foundation, a conservation NGO, said the situation at the time was chaotic. Some districts prohibited hunting of upland geese, while others permitted it, he said. But because female upland geese look very similar to ruddy-headed geese, an absolute ban was the only solution.

Resistance to the ban was strong, especially since farm owners would receive payments from hunters and tour operators to shoot on their land. Although a difficult task, raising awareness and holding dialogues through workshops helped change people’s views. Now, communities say they don’t want hunters traipsing through their lands. There’s also a much stronger commitment to upholding the ban and knowledge of the geese; for example, if someone witnesses a hunter shooting in a nearby field, they’re likely to report it to the police. Yet despite this progress, new issues have become apparent in the species’ nesting areas in Patagonia.

The main map (A) shows the route taken by the geese from their breeding areas in the south (C) to the “high density zone” in the province of Buenos Aires (B). Image courtesy of BirdLife International and Petracci et al.

Two breeding pairs in the country

The icy winds from the southernmost tip of the continent cross Estancia Cullen, a 7,800-hectare (19,000 acres) ranch in northeastern Tierra del Fuego, where thousands of sheep roam in semi-freedom. Within the estate lies a 5.3-hectare (13-acre) patch, fenced off with wire mesh to keep out cattle, foxes and minks, and where the vegetation grows taller than in the rest of the ranch. The area is dotted with dummies and photos of ruddy-headed geese, marking it out as an enclosure created specifically to encourage the birds to breed and nest here.

According to Petracci, who promotes the idea of giving the ruddy-headed goose an area in which to settle and breed, there are only two active breeding nests recorded in Argentina; the rest are in Chile.

The lack of favorable habitats for the species is the main factor behind its low reproductive rate, which in turn determines its future sustainability. The birds form monogamous pairs, with the females laying between four and 12 eggs per year. The chicks that hatch can’t fly until they’re around 50 days old, during which time they’re vulnerable prey for foxes, minks, kelp gulls (Larus dominicanus), large hairy armadillos (Chaetophractus villosus), and southern caracaras (Caracara plancus), a falcon-like bird of prey. To protect their chicks from these predators, the geese look for areas with sufficient vegetation cover, which have almost entirely disappeared from the southern Patagonian landscape.

The wire mesh prevents cattle, foxes and minks from entering the enclosure at Estancia Cullen on the island of Tierra del Fuego. Image courtesy of Pablo Petracci.

According to Chilean naturalist Ricardo Matus, director of the Leñadura Bird Rehabilitation Center, a leader in goose conservation in Chile’s Magallanes area, the reproduction rate of waterfowl such as ducks and geese can be high as long as there are suitable environments — such as marshes and wetlands — and there are no external threats (e.g. gray foxes or minks). If these conditions aren’t met, the chicks are unlikely to reach adulthood.

The Leñadura Bird Rehabilitation Center has since 2005 carried out a breeding program that began with the rescue of four ruddy-headed geese that couldn’t fly because of injuries. The birds started to reproduce in captivity, and the chicks raised there were eventually fitted with identification rings and set free.

Ruddy-headed geese and upland geese share the restored pastures of a small enclosure in Tierra del Fuego. So far, only upland geese have used the site for nesting and breeding. Image courtesy of Pablo Petracci.

The abrupt drop in the number of birds and their dispersal across large areas of land pose another issue for reproduction, making it increasingly difficult for males to find females with which to mate. According to Matus, who was among the conservationists who came up with the binational plan for joint action to save the species, signed by Argentina and Chile in 2013, there were 25 breeding pairs a few years ago when the total population was around 700 individuals. Today, the number of breeding pairs is thought to be half that.

The Estancia Cullen enclosure hasn’t yet been successful in terms of getting ruddy-headed geese to breed and nest, though upland geese have returned to nest in the regenerated area.

Profile of the ruddy-headed goose. Its black bill, the shade of its head feathers, and the fine black-and-white stripes on its body are distinctive features of the species. Image courtesy of Pablo Petracci.

A vital area for bird conservation

The situation is different in the birds’ wintering area. “We began by monitoring [the area] to define its importance for the ruddy-headed goose,” said Daniel Blanco, regional director for conservation NGO Wetlands International in Argentina. “We conducted systematic counts every winter for a decade, noting what fields they were in. For three goose species, it is a concentration point, but for the ruddy-headed goose, it is a unique site.”

The collected data were used to establish a “high density zone” of 13,000 hectares (32,000 acres). The site, which contains wetlands, marshes and lowlands comprising a mosaic of wheat fields and pastures, is now one of 23 grasslands in the country that qualify as an “important bird and biodiversity area.” Although it’s difficult to determine what specific characteristics attract the ruddy-headed goose, it’s likely that the higher terrain and more uniform crops a few kilometers to the north allow the birds to meet their daily food requirements and provide a place to sleep, which may not be the case in other locations.

A ruddy-headed goose depicted on a colorful mural decorating a large wall in front of the property where the annual National Wheat Fair is held in the city of Tres Arroyos. Image courtesy of Pablo Petracci.

Bahía Blanca Airport, the most important in the southwest of Buenos Aires province, is the main entry point for foreign hunters who continue to fly into the area to shoot geese, often unaware that it’s a prohibited activity and that they’ll have to do it in a clandestine way. To raise awareness, authorities have put up notices explaining the situation, and previously held meetings with representatives of foreign embassies to also inform them of the goose-hunting ban.

In Tres Arroyos, a city located 60 km (37 mi) north of the high-density area, an emblematic mural was painted in front of the property where the annual National Wheat Festival takes place. More recently, in the contracts signed between a milling company based in the southeast of the province and its grain suppliers, a clause was introduced binding both parties not to chase away or kill any geese.

Members of the Azara Foundation and El Tamarisco farm put up a sign showing that the area is a goose sanctuary, the only one in the country. Image courtesy of Pablo Petracci.

The best-known conservation activity, however, has been the creation of a goose sanctuary in El Tamarisco, Carlos Pardo’s farm, following an idea that arose from one of the visits that Ibáñez and Petracci made to the farm to count geese. According to Pardo, most of the ruddy-headed geese that came from the south stopped in his field, with 1,057 counted in the entire area one year; 900 of them were in the area now designated the sanctuary. Now, according to Pardo, no more than 400 geese stop over.

The sanctuary features a wooden hide from which people can take photos. It has become almost an obligatory stopping point for bird-watchers in the area. While Pardo doesn’t charge an admission fee for entry to the sanctuary, visitors donations that Pardo then gives to a school in Orense, a town 20 km (12 mi) away.

The birds that Matus ringed in Chilean Patagonia have been observed in El Tamarisco. The data from these ringed birds are contributing to the growing knowledge of the migratory route of the geese, complemented by studies (albeit just a few) carried out with satellite transmitters.

Students from schools near Tres Arroyos taking part in a welcome festival for the geese, an initiative to promote knowledge of the species among new generations. Image courtesy of Pablo Petracci.

Such work makes it possible to anticipate the last hurdle that the geese face in the fight against extinction: clean energy in the form of wind farms.

“In [Chile’s] Magallanes, there are already many projects underway to produce green hydrogen,” Matus said. “These large wind farms will be a danger to migratory birds.”

Since the exact routes of the geese’s migrations aren’t yet fully known, the danger of collisions with the new wind turbines is especially concerning: the windmills stand 120 meters (nearly 400 feet) tall, and the geese fly at altitudes of 80-100 m (260-330 ft) — well within range of being struck by the spinning turbine blades.

Although the number of goose deaths from windmills to date pales in comparison to the past toll from just a single day of hunting, the bird’s population is now much smaller than back then. Amid this shrinking population, the number and variety of dangers that threaten the ruddy-headed goose only continue to grow.

Ruddy-headed geese walking through a field near a wind farm in the southwest of Buenos Aires province. The increase in the number of windmills is a new danger to this species. Image courtesy of Pablo Petracci.

Banner image of a ruddy-headed goose spreading its wings, courtesy of Pablo Petracci.

This story was reported by Mongabay’s Latam team and first published here on our Latam site on Oct. 26, 2022.

This story first appeared on Mongabay

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