Justification of Red List Category
This species has a very large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). Despite the fact that the population trend appears to be decreasing, the decline is not believed to be sufficiently rapid to approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size may be small, but it is not believed to approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.
The species has a large global population estimated to number 11,000-26,000 individuals (Delaney and Scott 2006), roughly equivalent to 7,300-18,000 mature individuals. The Falkland/Malvinas Islands population is estimated at 600-1,200 birds, although the population trend appears to be unknown (Woods and Woods 1997). Reports from Argentina suggest that the species is still numerous, particularly in Patagonia (M. Pearman in litt. 2003).
The overall population trend is decreasing, although some populations have unknown trends (Delaney and Scott 2006).
This species is found in southern Chile, in the extreme southern Argentina (Tierra del Fuego) and the Falkland Islands (Islas Malvinas).
This species occurs both inland on freshwater lakes, pools and rivers, and, during the non-breeding season, along rocky coastlines. It primarily consumes aquatic invertebrates captured both in salt and fresh water by diving. Its breeding season starts in October or November, when it creates well concealed nests among vegetation on small islets. It is largely sedentary, with only small-scale movements along the coast after the breeding season (del Hoyo et al. 1992).
Hunting and egg collecting occurs throughout the species' mainland range but is not systematic and not thought to be driving significant decline (Kear 2005). Disturbance by tourists during the breeding season threatens a tiny proportion of the global population (Kear 2005). There is also the possibility of oil spills impacting this species; however, the species does not have the aggregating habit of many other seaducks, hence is considered less vulnerable (Kear 2005).
Text account compilers
Palmer-Newton, A., Stuart, A., Ekstrom, J., Butchart, S., Fisher, S., Calvert, R., Fjagesund, T., Harding, M., Hermes, C., Martin, R.
BirdLife International (2021) Species factsheet: Tachyeres patachonicus. Downloaded from http://www.birdlife.org on 17/10/2021. Recommended citation for factsheets for more than one species: BirdLife International (2021) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 17/10/2021.