Of the six species of flamingos in the world today, three are restricted to southern South America. The most widespread is the Chilean flamingo, which can be found in wetlands from northern Peru to Tierra del Fuego on the southern tip of the continent. Classified as Near Threatened by IUCN, the Chilean flamingo has an estimated population of around 500,000 birds, but its numbers have been dropping due to habitat loss, pollution, and the disturbance of its breeding colonies.

WCS has been monitoring the breeding success of the Chilean flamingo in a colony in the southern limit of its breeding range, near the town of Rawson in Argentine Patagonia, since 2016. This colony has numbered more than 6,000 active nests that produced over 2,000 fledglings in some years and fewer than 1,500 nests and under 300 fledglings in others, and in two years no nests were built and the birds failed to breed altogether. Annual variation in breeding success is common in flamingos, in fact this colony is more regular than most.

Recently, WCS resumed monitoring of a second breeding site at Laguna Aleusco Natural Protected Area, nearer the Andes, where WCS has recorded Chilean flamingos settling since the 1970s. For a long time the birds stopped breeding there, possibly because of lack of water and/or food, however they began doing so again in recent years and between 2,200 and 5,200 nests producing 75 to 516 fledglings were recorded.

Flamingos are long-lived birds that can go several years without breeding and not suffer significant population loss as long as they are successful every so often.

WCS is working with government agencies and the local community in the province of Chubut to increase awareness of the existence of flamingo colonies to ensure their protection. Other birds species that use these wetlands will also benefit, including the rare and endangered Magellanic plover, endemic to southern Argentina and Chile.