It is the largest species of toucan and has a distinctive appearance, with a black body, a white throat, chest and uppertail-coverts, and red undertail-coverts.

Toco toucans mainly feed on fleshy fruits, but also supplement their diets with insects, eggs, and the nestlings of other birds.

They will eat any available sugar-rich fruits, and show a high level of variation in their diet depending on the surrounding habitat.

The oldest known remains of the toco toucan date back to around 20,000 years ago, from Pleistocene deposits in Lagoa Santa, Minas Gerais.

[3] The first European account of the species was written by the French naturalist Pierre Belon in his 1555 work Histoire de la nature des oyseaux.

[4] The species was formally described as Ramphastos Toco by the German zoologist Philipp Ludwig Statius Müller in 1776 on the basis of specimens from Cayenne, French Guiana.

[5] In 1862, the German ornithologist Jean Cabanis described R. albogularis as a new species based on specimens from southern Brazil;[6] by 1870, it had been demoted to the status of a subspecies of R.

[13] Later studies of mitochondrial DNA have largely confirmed the existence of these two clades, but have found the toco toucan to be basal within the family instead of being a part of the channel-keel-billed croakers.

This white patch will sometimes have a citrine yellow tint and a red band where it meets the black breast, but these features are highly variable between individuals.

[3][11][16] The extremely long and thin bill is usually reddest along the top of the culmen and has irregular orangish-brown bands on its sides, across the tomia.

It is further found from coastal Maranhão southwest to southwestern Brazil, Bolivia, and Pampas de Heath in far southeastern Peru, and south through Piauí and Bahia to northern Argentina and Uruguay.

[11] Similarly, it has only been recorded from Uruguay recently; previously, the southward limit of its range was Lagoa dos Patos in Brazil.

The recent expansion its range south of the 30th parallel may be caused by escapes of captive individuals or changes in ecological conditions.

[11] After the end of the breeding season, toco toucans will sometimes form large flocks that fly around forests searching for fruit.

[23] Further suggestions have included aid in peeling fruit, intimidating other birds when robbing their nests, social selection related to defense of territory, and as a visual warning.

It has been observed that "complexities of the vasculature and controlling mechanisms needed to adjust the blood flow to the bill may not be completely developed until adulthood.

[25] Toco toucans are generalist frugivores that primarily feed on fleshy fruits, but also commonly supplement their diets with insects, eggs, and nestlings of other birds.

[11] Other plants that fruit year-round and feature significantly in the species's diet include Cecropia pachystachya and Inga laurina.

[21][26] Toucans will also opportunistically feed on any available sugar-rich fruits, and display a high level of variation in their diet depending on the surrounding habitat.

[27][28] Plants that have been recorded as contributing majorly to the toco toucan's diet include Genipa americana, Ficus luschnatiana, and Virola sebifera in gallery forest,[21][27] Schefflera macrocarpa, Copaifera langsdorffii, Didymopanax morototoni, and Nectandra cissiflora in the cerrado,[27][29] and Guibourtia hymenaefolia and D. morototoni in semi-deciduous forests.

[28] During the dry season when the availability of fruits declines, toco toucans will also feed on flowers of species such as Handroanthus chrysotrichus and Erythrina fusca.

[33] In captivity, toucans will feed on a number of smaller birds that are placed with them, such as Toxostoma thrashers, house sparrows, Inca doves, cactus wrens, and Gambel's quails.

[11] Nesting occurs in cavities, which are usually made in trees such as coral cockspur and slash pines, but which can also be in stream banks or termite mounds.

[11][34] Successful breeding has also been observed in urban areas, although high levels of human-caused disturbances, such as construction activities, around the nest can lead to abandonment by the parents.

[22] Although toco toucans mainly feed on native species, some invasive plants, like Royostenia oleracea and Elaeis guineensis, do represent significant portions of their diet.

[11] The species is also parasitized by the protozoans Plasmodium nucleophilum, P. huffi, P. pinottii,[38] Toxoplasma gondii,[39] and Giardia duodenalis,[40] Trichomonas parabasalids,[41] and trematodes.

[42] Because it prefers open habitats, the toco toucan is likely to benefit from the widespread deforestation in tropical South America;[1] it is known to inhabit areas around airports and newly-made roads.

[3] In the mythology of the Ayoreo people of the Gran Chaco of Bolivia and Paraguay, the word for toco toucan, Carai, is also the name of a honey hunter.