5 thoughts on “Spectacled Duck (Speculanas specularis)”
Dear committee,
Our NGO (Red de Observadores de aves y vida silvestre de Chile) worked on the update of the Spectacled Duck during 2024 (Díaz Morales et al. 2024). We agree that the species does not reach any threshold to be classified as Vulnerable. However, we disagree on whether there is enough information to determine the population trend is “stable.” The population might be declining, out of our sight.
There is a continuous advance in the distribution of the exotic American Mink, which is even reaching the most remote breeding areas like Cape Horn (Barroso et al. 2024), and it is known that when the American Mink is present, the Spectacled Duck is absent (Girini 2018), and according to the Birds of the World account, there are negative impacts associated to habitat loss, such as dams construction, and forest fires.
In Argentina the population could have suffered a reduction of more than 30%, and it is possibly to continue declining (MAyDS 2017), and its hybridization with the exotic Mallard (that is also expanding in Chile recently) could severely affect its populations in the future.
Considering the advance of these threats, and the fact that the population trend has not been really studied in the recent years, we suggest keeping the species classified as “Near Threatened”.
References
Díaz Morales, J., V. Pantoja-Maggi, J. Cabezas, and P. Pyle (2024). Spectacled Duck (Speculanas specularis), version 2.0. In Birds of the World (M. G. Smith, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.speduc2.02
Girini, J. M. (2018). Cambios en los ensambles y poblaciones de Aves ante la presencia del Visón americano Neovison vison en lagos del norte de la Patagonia andina. Ph.D. dissertation, Universidad Nacional de la Plata, Argentina.
MAyDS (Ministerio de Ambiente y Desarrollo Sustentable and Aves Argentinas) (2017). Categorización de las Aves de la Argentina (2015). Informe del Ministerio de Ambiente y Desarrollo Sustentable de la Nación y de Aves Argentinas, edición electrónica. C. A., Buenos Aires, Argentina.
The Spectacled Duck is a habitat specialist confined to certain aquatic environments in Patagonia. It does not utilize all available water bodies, but rather selects specific areas—primarily associated with rivers featuring backwaters and small shallow lakes. Consequently, the reported extent of occurrence (EOO) of 1,040,000 km² is, as with most habitat specialists, a substantial overestimation.
Nevertheless, even using this broad EOO estimate, there is evidence of a current range reduction of at least 43%, equivalent to approximately 450,000 km². In this extensive area, no stable populations have been recorded over the past 20 years (based on data from eBird and unpublished personal observations).
The most significant decline or disappearance of populations has been documented in central Patagonia, from southern Neuquén (Argentina) to southern Chubut, including large portions of the Chilean fjordlands further south. Across this entire region, only small pockets of sporadic records or isolated populations remain. Large protected areas in Argentina, such as half of Lanín National Park, and all of Nahuel Huapi and Lago Puelo National Parks, have lost their populations (personal unpublished data).
This significant population decline aligns with the advancing invasion front of the American mink (Neogale vison) across Patagonia (Fasola et al. 2021). Since the mid-20th century, the mink has expanded from multiple introduction points, spreading both northward and southward. It now occupies almost all of Patagonia, with the apparent exception of a few small areas in southern Patagonia, although signs of continued expansion are present.
In the southernmost part of Patagonia (Santa Cruz, Argentina, and Magallanes, Chile), some seemingly stable populations still exist—for example, in Los Glaciares National Park, Argentina. The northern sector of this park holds the densest population, where an aggressive mink control program is underway. However, even there, the breeding population does not exceed 15–20 pairs.
Based on the most robust known populations, it is likely that the global adult population is close to the lower bound estimate, potentially no more than 2,500 mature individuals, and composed of a few localized subpopulations.
Given a possible EOO reduction of nearly 50%, the ongoing spread of new and significant threats—notably the American mink and climate change affecting Patagonian hydrological cycles (Lancelotti et al. 2020)—we recommend a reevaluation of the species’ conservation status, possibly uplisting it to Vulnerable or even Endangered.
References:
Fasola, L., Zucolillo, P., Roesler, I. & Cabello, J.L. (2021) Foreign Carnivore: The Case of American Mink (Neovison vison) in South America. Biological Invasions in the South American Anthropocene pp. 255–299.
Lancelotti, J.L., Pssacg, N.L., Roesler, I.C. & Pascual, M.A. (2020) Climate variability and trends in the reproductive habitat of the critically endangered hooded grebe. Aquatic Conservation: Marine and Freshwater Ecosystems, 30, 554–564.
Many thanks to everyone who has contributed to this discussion. We greatly appreciate the time and effort invested in commenting. The window for consultation is now closed and we are unable to accept any more comments until 25 April 2025. We will now analyse and interpret the information, and we will post a preliminary decision on this species’ Red List category on this page on 25 April 2025, when discussions will re-open.
We thank all those who have contributed valuable information. Based on this, the population trend is inferred to be decreasing due to predation by mink and this has been changed accordingly in the updated Red List assessment. In the absence of a direct quantification of the population size, the species does not meet the threshold for Vulnerable under Criterion C. Based on available information therefore, our preliminary proposal for the 2025 Red List would be to list Spectacled Duck as Near Threatened, approaching thresholds under Criterion C2a(ii).
There is now a period for further comments until the final deadline on 4 May 2025, after which the recommended categorisations will be put forward to IUCN.
The final 2025 Red List categories will be published on the BirdLife and IUCN websites in October 2025, following further checking of information relevant to the assessments by both BirdLife and IUCN.
Many thanks to everyone who has contributed to this discussion. We greatly appreciate the time and effort invested in commenting. The window for consultation is now closed and we are unable to accept any more comments. We will analyse and interpret the information, and a final decision on this species’ Red List category will be posted on this page on 12 May 2025.
Dear committee,
Our NGO (Red de Observadores de aves y vida silvestre de Chile) worked on the update of the Spectacled Duck during 2024 (Díaz Morales et al. 2024). We agree that the species does not reach any threshold to be classified as Vulnerable. However, we disagree on whether there is enough information to determine the population trend is “stable.” The population might be declining, out of our sight.
There is a continuous advance in the distribution of the exotic American Mink, which is even reaching the most remote breeding areas like Cape Horn (Barroso et al. 2024), and it is known that when the American Mink is present, the Spectacled Duck is absent (Girini 2018), and according to the Birds of the World account, there are negative impacts associated to habitat loss, such as dams construction, and forest fires.
In Argentina the population could have suffered a reduction of more than 30%, and it is possibly to continue declining (MAyDS 2017), and its hybridization with the exotic Mallard (that is also expanding in Chile recently) could severely affect its populations in the future.
Considering the advance of these threats, and the fact that the population trend has not been really studied in the recent years, we suggest keeping the species classified as “Near Threatened”.
References
Díaz Morales, J., V. Pantoja-Maggi, J. Cabezas, and P. Pyle (2024). Spectacled Duck (Speculanas specularis), version 2.0. In Birds of the World (M. G. Smith, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.speduc2.02
Girini, J. M. (2018). Cambios en los ensambles y poblaciones de Aves ante la presencia del Visón americano Neovison vison en lagos del norte de la Patagonia andina. Ph.D. dissertation, Universidad Nacional de la Plata, Argentina.
MAyDS (Ministerio de Ambiente y Desarrollo Sustentable and Aves Argentinas) (2017). Categorización de las Aves de la Argentina (2015). Informe del Ministerio de Ambiente y Desarrollo Sustentable de la Nación y de Aves Argentinas, edición electrónica. C. A., Buenos Aires, Argentina.
The Spectacled Duck is a habitat specialist confined to certain aquatic environments in Patagonia. It does not utilize all available water bodies, but rather selects specific areas—primarily associated with rivers featuring backwaters and small shallow lakes. Consequently, the reported extent of occurrence (EOO) of 1,040,000 km² is, as with most habitat specialists, a substantial overestimation.
Nevertheless, even using this broad EOO estimate, there is evidence of a current range reduction of at least 43%, equivalent to approximately 450,000 km². In this extensive area, no stable populations have been recorded over the past 20 years (based on data from eBird and unpublished personal observations).
The most significant decline or disappearance of populations has been documented in central Patagonia, from southern Neuquén (Argentina) to southern Chubut, including large portions of the Chilean fjordlands further south. Across this entire region, only small pockets of sporadic records or isolated populations remain. Large protected areas in Argentina, such as half of Lanín National Park, and all of Nahuel Huapi and Lago Puelo National Parks, have lost their populations (personal unpublished data).
This significant population decline aligns with the advancing invasion front of the American mink (Neogale vison) across Patagonia (Fasola et al. 2021). Since the mid-20th century, the mink has expanded from multiple introduction points, spreading both northward and southward. It now occupies almost all of Patagonia, with the apparent exception of a few small areas in southern Patagonia, although signs of continued expansion are present.
In the southernmost part of Patagonia (Santa Cruz, Argentina, and Magallanes, Chile), some seemingly stable populations still exist—for example, in Los Glaciares National Park, Argentina. The northern sector of this park holds the densest population, where an aggressive mink control program is underway. However, even there, the breeding population does not exceed 15–20 pairs.
Based on the most robust known populations, it is likely that the global adult population is close to the lower bound estimate, potentially no more than 2,500 mature individuals, and composed of a few localized subpopulations.
Given a possible EOO reduction of nearly 50%, the ongoing spread of new and significant threats—notably the American mink and climate change affecting Patagonian hydrological cycles (Lancelotti et al. 2020)—we recommend a reevaluation of the species’ conservation status, possibly uplisting it to Vulnerable or even Endangered.
References:
Fasola, L., Zucolillo, P., Roesler, I. & Cabello, J.L. (2021) Foreign Carnivore: The Case of American Mink (Neovison vison) in South America. Biological Invasions in the South American Anthropocene pp. 255–299.
Lancelotti, J.L., Pssacg, N.L., Roesler, I.C. & Pascual, M.A. (2020) Climate variability and trends in the reproductive habitat of the critically endangered hooded grebe. Aquatic Conservation: Marine and Freshwater Ecosystems, 30, 554–564.
Many thanks to everyone who has contributed to this discussion. We greatly appreciate the time and effort invested in commenting. The window for consultation is now closed and we are unable to accept any more comments until 25 April 2025. We will now analyse and interpret the information, and we will post a preliminary decision on this species’ Red List category on this page on 25 April 2025, when discussions will re-open.
Preliminary proposal
We thank all those who have contributed valuable information. Based on this, the population trend is inferred to be decreasing due to predation by mink and this has been changed accordingly in the updated Red List assessment. In the absence of a direct quantification of the population size, the species does not meet the threshold for Vulnerable under Criterion C. Based on available information therefore, our preliminary proposal for the 2025 Red List would be to list Spectacled Duck as Near Threatened, approaching thresholds under Criterion C2a(ii).
There is now a period for further comments until the final deadline on 4 May 2025, after which the recommended categorisations will be put forward to IUCN.
The final 2025 Red List categories will be published on the BirdLife and IUCN websites in October 2025, following further checking of information relevant to the assessments by both BirdLife and IUCN.
Many thanks to everyone who has contributed to this discussion. We greatly appreciate the time and effort invested in commenting. The window for consultation is now closed and we are unable to accept any more comments. We will analyse and interpret the information, and a final decision on this species’ Red List category will be posted on this page on 12 May 2025.