Brazilian Merganser - Definition and Overview

The Brazilian Merganser (Mergus octosetaceus) is a typical merganser.

This is a dark, slender duck with a long crest. It has a dark hood with petroleum-green sheen, a pale grey breast and dark grey upperparts. It has a long, bushy hindcrest usually worn and shorter in females.

Their breeding habitat is shallow, fast-flowing rivers in south-central Brazil. They nest in tree-cavities and possibly rock-cavities. They mainly eat fish, small eels, insect larvae, dobson flies (Corydalis sp.) and snails.

This species is critically endangered. Numbers have reduced due to polluted rivers caused by forest clearance and agriculture. The current population is estimated at less than 250.