It formerly included the similar black-faced ibis as a subspecies, but that species is almost entirely restricted to colder parts of South America, has a buff (not dark grey) lower chest, and lacks the contrasting large white wing-patches.

[2] The bird was also illustrated in a hand-coloured plate engraved by François-Nicolas Martinet in the Planches Enluminées D'Histoire Naturelle which was produced under the supervision of Edme-Louis Daubenton to accompany Buffon's text.

[3] Neither the plate caption nor Buffon's description included a scientific name but in 1783 the Dutch naturalist Pieter Boddaert coined the binomial name Scolopax caudatus in his catalogue of the Planches Enluminées.

With a large range and an estimated population of 25,000 to 100,000, the buff-necked ibis is evaluated as Least Concern on the IUCN Red List of Threatened Species.

Its diet consists mainly of insects, spiders, frogs, reptiles, snails, invertebrates and small mammals found in soft soils.