Crimson-rumped Toucanet

Aulacorhynchus haematopygus

Cali Valle Del Cauca Colombia

Quick Facts

  • Scientific Name: Aulacorhynchus haematopygus
  • Spanish Name: Tucancito lomo rojo
  • Family: Ramphastidae
  • Known Nicknames: Crimson-rumped Toucanet
  • Average Length: 35–44 cm / 14–17 in
  • Average Weight: 141–232 g / 5.0–8.2 oz
  • Wingspan: 46–52 cm / 18–20.5 in
  • Key Feature: Vibrant crimson-red rump and a maroon-red patch at the base of the bill
  • Primary Diet: Primarily Frugivore (also consumes insects, eggs, and small vertebrates)
  • Range: Andes of Colombia, Ecuador, and Venezuela
  • Habitat: Humid montane forest, cloud forest, and forest edges
  • Social Structure: Social; typically found in pairs or small family groups
  • Nesting/Breeding: Tree cavities (often abandoned woodpecker holes)
  • Conservation Status: Least Concern (LC)
  • Population Trend: Stable

The Crimson-rumped Toucanet (*Aulacorhynchus haematopygus*) is a vibrant emerald gem of the Andean cloud forests, distinguished by its lush, grass-green plumage and the startling splash of deep crimson on its lower back from which it takes its name. This medium-sized toucanet possesses a formidable yet elegant bill, typically colored in shades of dark maroon and black with a crisp white band at the base, and striking bare skin around the eyes that ranges from pale blue to grey. Renowned for its social nature, this agile bird often moves through the misty canopy in small, spirited groups, using its specialized beak to forage for a diverse diet of tropical fruits, insects, and occasionally small vertebrates. Its combination of camouflaging greenery and brilliant red accents makes it a captivating spectacle for birdwatchers navigating the high-altitude humid forests of South America.

Fun Facts

Despite their vibrant green camouflage, these birds possess a hidden flash of brilliant maroon on their rumps that is typically visible only during flight or social displays. They exhibit a peculiar "toss-and-catch" eating style; because their long, frayed tongues are better suited for tasting than moving food, they must flip fruit into the air and catch it at the back of their throats to swallow. To stay safe while sleeping in cramped tree hollows, they perform a remarkable feat of flexibility by folding their long tails flat against their backs and tucking their oversized beaks under their wings, transforming into a compact, feathery ball. Additionally, their serrated, saw-like bills are not just for fruit, as they are surprisingly opportunistic hunters known to snatch large insects and even small lizards.

Habitats & Distribution

This species is primarily distributed across the humid Andean regions of northwestern South America, inhabiting the slopes of the Western, Central, and Eastern Andes in Colombia, Ecuador, and northwestern Venezuela. It typically occupies an altitudinal range between 600 and 2,200 meters above sea level, though it is most commonly found in the subtropical and temperate zones of these mountain ranges.

The preferred habitat consists of humid montane forests, cloud forests, and dense woodland edges characterized by high moisture and an abundance of epiphytes. While it thrives in primary forest environments, it is also known to frequent older secondary growth and shaded plantations, such as those for coffee or fruit, provided there is nearby forest cover. It generally stays within the middle and upper levels of the canopy, navigating through moss-covered branches to forage.

Behaviours & Reproduction

These birds are primarily social, typically found in pairs or small family groups that move actively through the forest canopy. They often engage in "bill-fencing," a behavior involving rhythmic beak-clashing that serves as both social play and a means of establishing dominance. While foraging, they maintain group cohesion through repetitive, croaking vocalizations. Although fruit makes up the bulk of their diet, they exhibit opportunistic predatory behaviors by raiding the nests of other birds for eggs and nestlings, which provides essential protein during the breeding season.

Reproduction is characterized by monogamous pair bonds reinforced through ritualized fruit-feeding, where the male presents food to the female to strengthen their connection. They are secondary cavity nesters, occupying abandoned woodpecker holes or natural tree hollows high above the ground. Both parents share the duties of incubating the clutch of two to four eggs and brooding the chicks. This biparental care is a critical strategy for the survival of their slow-developing, altricial young, ensuring constant protection and a steady food supply within the competitive Andean cloud forest ecosystem.

Diet

The Crimson-rumped Toucanet is primarily a frugivorous bird, focusing its diet on a diverse array of tropical fruits and berries found within the humid forest canopy. While fruit constitutes the majority of its sustenance, this species is also an opportunistic omnivore that supplements its nutritional needs with animal protein, including large insects, spiders, small lizards, and occasionally the eggs or nestlings of other birds. One of the most interesting aspects of its feeding ecology is its significant role as a seed disperser; the toucanet often swallows fruits whole and later regurgitates the larger seeds or passes smaller ones through its digestive system, effectively planting future trees throughout its habitat. Its elongated, serrated bill is a specialized evolutionary tool that allows it to reach fruit on thin, distal branches that cannot support its weight, and it is known to use a "toss-and-gulp" method, throwing food items into the air to catch them at the back of its throat for easy swallowing.

Colors

Primarily grass-green for canopy camouflage, the Crimson-rumped Toucanet is defined by a vivid red patch on its lower back. Its heavy bill is dark maroon with a thin, white vertical band at the base, complemented by subtle blue-gray skin around the eyes.