Critically Endangered
Brazilian Merganser
Mergus octosetaceus
The Brazilian merganser is a South American diving duck in the Mergus genus.
Appearance
This merganser is a dark, slender duck with a shiny dark-green hood with a long crest, that is usually shorter and more worn-looking in females. Upperparts are dark grey while the breast is light grey, getting paler toward the whitish belly, and a white speculum is particularly noticeable in flight. It has a long thin jagged black bill with red feet and legs.
Published measurements include mass about 650.
Range and habitat
The slender Brazilian mergansers live in low densities in remote and mountainous regions where it inhabits clean rivers and streams with river rapids and riparian vegetation. Brazilian mergansers are very territorial birds defending large stretches of river and the land surrounding the fast-flowing water. The birds need large territories and their habitat is fast dwindling.
Pins are Wikidata “endemic to” fields. Orange dots, when present, are GBIF occurrence tiles — survey bias included.
In crisis
It is one of the most threatened waterfowl species in the world, with possibly fewer than 250 birds in the wild and a small number kept in captivity in Brazil and Czechia. The merganser population is believed to have less than 250 birds. Currently, all confirmed populations are located in Brazil and a more recent population in Argentina and information on most populations is very scarce.
There are 47 individuals—28 adults and 19 young—in the Serra de Canastra region as of 2006. In Jalapão region are estimated 13 individuals in Novo river on 2009/2010 (four couples and some solitary adults).
Brazilian Merganser is Critically Endangered on this catalog because that is the IUCN category stored on Wikidata. Confirm the official criteria and any later count on iucnredlist.org.
Sources
Written for this catalog from the English Wikipedia article on Brazilian Merganser, Wikidata item Q907237. Family and order context is original field-guide writing about the group, not a copied assessment of this one species. Wikipedia text is CC BY-SA. Not an IUCN assessment. Counts, when quoted, can change — confirm them on the recovery programme and on iucnredlist.org.
