They are common across South America and have been recorded in Ecuador, the Falkland Islands, Uruguay, Brazil, and as far away as Antarctica.

[4][9] Adult males have a gray face, neck, and breast, and have black lines at the center of the throat that form an inverted “T” shape.

The thermoneutral zone extends from 33 to 38 °C in this species, but they have the capacity to dissipate heat through evaporative water loss up to 42 °C.

Their metabolic rate is 38% lower than other non-passerine birds of similar body mass (~50 g), reducing the contribution to the total heat budget.

The primary purpose for nest covering in Thinocorus rumicivorus is most likely concealment from predators, but thermoregulation probably also plays a factor.

[11] As the common name suggests, least seedsnipes rely mostly on seeds, but they will also eat leaves and buds and as such are strictly vegetarian in their natural habitat.