Araçari à oreillons

En bref

  • Scientific Name: Pteroglossus castanotis
  • Spanish Name: Arasarí de orejas castañas
  • Family: Ramphastidae
  • Known Nicknames: Chestnut-eared Toucanet
  • Average Length: 40–46 cm / 16–18 in
  • Average Weight: 220–310 g / 7.8–10.9 oz
  • Envergure : N/A
  • Key Feature: Bright yellow and red belly band, chestnut ear patch, and long, bicolored bill
  • Régime alimentaire principal : Principalement frugivore
  • Range: South-central South America (eastern Peru, northern Bolivia, central and western Brazil, Paraguay, northern Argentina)
  • Habitat: Lowland tropical and subtropical moist forests, gallery forests, and forest edges
  • Structure sociale : Très sociable
  • Nidification/Reproduction : Cavités d'arbres
  • Statut de conservation : Préoccupation mineure (LC)
  • Évolution démographique : Stable

The Chestnut-eared Aracari (*Pteroglossus castanotis*) is a strikingly social and colorful toucan relative found in the lowland forests of South America. Its most distinctive feature is the rich, chestnut-brown patch behind the eye and extending down the ear, which contrasts vividly with its glossy black head and bright yellow throat. This medium-sized bird boasts a spectacular, oversized bill that is a patchwork of ivory, black, and orange, while its underparts are a brilliant mix of yellow and red, often with a bold black spot on the chest. A special feature is its communal nesting behavior, where multiple adults often help raise a single brood, and its loud, sharp calls echo through the canopy as it forages for fruit, insects, and even small lizards.

Faits amusants

The Chestnut-eared Aracari is a toucan relative with a surprisingly social and theatrical personality. Despite its large, colorful bill, it is a master of agility, often hanging upside down to pluck fruit from thin branches. It engages in a quirky behavior called “bill-fencing,” where two birds cross and tap their beaks together in a rapid, non-aggressive greeting or courtship ritual. Unlike many birds, it sleeps with its long tail folded over its back to fit into tree cavities, and it has a unique adaptation where it can adjust the blood flow to its bill to regulate body temperature, essentially using its beak as a radiator.

Habitats et répartition

The Chestnut-eared Aracari primarily inhabits lowland tropical and subtropical moist forests, including terra firme and várzea forests, as well as forest edges, clearings, and secondary growth. It is also found in gallery forests and plantations, often staying in the canopy or mid-story. Its geographical range spans across central and eastern South America, including much of the Amazon Basin in Brazil, as well as eastern Peru, northern Bolivia, eastern Ecuador, Colombia, Venezuela, and the Guianas, extending into parts of central and eastern Brazil.

Comportements & Reproduction

These toucans are highly social, typically living in small, noisy flocks of up to ten individuals. Their breeding behavior is monogamous, with pairs forming strong, long-term bonds. During courtship, they engage in mutual feeding, where the male offers fruit to the female, and they also perform a ritualized bill-touching display. Nests are usually placed in natural tree cavities, which the pair may enlarge or modify. A unique reproductive strategy is the use of communal roosting and nesting assistance; younger or non-breeding flock members often help incubate eggs and feed chicks, a behavior known as cooperative breeding. The female lays 2–4 white eggs, and both parents, along with helpers, share incubation duties for about 16 days, with fledglings leaving the nest after roughly 6 weeks.

Alimentation

The Chestnut-eared Aracari is primarily a frugivore, with fruit making up the vast majority of its diet, but it is also an opportunistic omnivore. It actively seeks out a wide variety of tropical and subtropical fruits, especially palm fruits and figs, often swallowing them whole and later regurgitating the large seeds, making it a crucial seed disperser for the forest. A fascinating aspect of its feeding behavior is its tendency to supplement its fruit-heavy diet with animal protein, including insects like termites and beetles, as well as small lizards, tree frogs, and even the eggs and nestlings of other bird species, which it piratically steals from nests. Furthermore, this aracari has been observed visiting clay licks, a behavior known as geophagy, where it consumes soil to help neutralize toxins found in unripe or certain acidic fruits and aid in digestion.

Couleurs

The Chestnut-eared Aracari has a black head and upper breast, with a distinctive chestnut-brown ear patch and a bright yellow lower breast and belly crossed by a red band and a black spot. Its upperparts are dark green, the rump is red, and the tail is dark with red tips. The bill is large and colorful, featuring a yellow-orange upper mandible with a black tip and a black lower mandible. Its most unique adaptation is the vivid, contrasting colors on the bill and underparts, which serve as species recognition signals rather than camouflage, as it relies on dense canopy cover for concealment.