A South American wetland stilt. Adults often show a white crown and a white bar across the upper back. A Brazilian study documented nests made with salt-marsh vegetation, mud, and shells.
Adults usually show a white crown and a white bar across the upper back between the black neck and back; juveniles have different black-and-white patterning.
It nests low in salt-marsh vegetation using plants, mud, and shells. At Brazil's Jurubatiba National Park, 34 nests were monitored in 2018–2020; breeding was mainly in September–October and nine nests succeeded.
Its contact calls are repeated, mellow, wheezy barking notes. It sometimes also gives high squeaky calls.
Males have glossy black upperparts, sometimes with a greenish sheen. Females and older immatures typically have dark brown over much of the back.
Juveniles have less distinct markings and mostly dark heads and upper backs. As they mature, the head and upper back become whiter in stages.
An extinction-risk assessment has not been added yet.