Tangara à croupion rouge

En bref

  • Scientific Name: Ramphocelus passerinii
  • Spanish Name: Tangara escarlata
  • Famille : Thraupidae
  • Known Nicknames: Passerini's Tanager, Scarlet-rumped Tanager
  • Average Length: 16–18 cm / 6.3–7.1 in
  • Average Weight: 30–40 g / 1.1–1.4 oz
  • Envergure : N/A
  • Key Feature: Male has jet-black body with a vivid scarlet-red rump and lower back
  • Régime alimentaire principal : Principalement frugivore
  • Range: Caribbean slope from southern Mexico to western Panama
  • Habitat: Humid lowland and foothill forests, forest edges, and secondary growth
  • Structure sociale : Très sociable
  • Nidification/Reproduction : Nid en forme de coupe situé dans une fourche d'arbre ou un arbuste
  • Statut de conservation : Préoccupation mineure (LC)
  • Évolution démographique : Stable

The Scarlet-rumped Tanager (*Ramphocelus passerinii*) is a dazzling songbird of Central America, renowned for its starkly beautiful contrast: the male is a deep, velvety black over most of its body, dramatically punctuated by a brilliant, fiery crimson patch on its lower back and rump. A unique feature is its striking, pale silver-blue bill, which appears almost luminous against the dark plumage, while females are a more subdued olive-brown with a duller, yellowish rump. This species is often found in noisy, active flocks along forest edges and plantations, where its bold coloration and habit of perching conspicuously make it a favorite among birdwatchers. A special behavioral trait is its frequent tail-wagging and its role as a key seed disperser, helping to maintain the health of its tropical ecosystem.

Faits amusants

Despite its name, only the male sports that brilliant crimson rump and lower back; females are a muted olive-brown, a stark sexual dimorphism that can make them look like entirely different species. They are aggressive nectar thieves, often piercing the base of flowers with their strong, sharp bills to access nectar without pollinating the plant. A quirky social behavior is their tendency to engage in "allopreening," where pairs or small groups will meticulously preen each other's head and neck feathers, reinforcing pair bonds and social hierarchies. They also have a unique, metallic "chee-up" call that sounds almost electronic, used to maintain contact as they forage in noisy, mixed-species flocks.

Habitats et répartition

The Scarlet-rumped Tanager occupies lowland and foothill regions from southern Mexico through Central America, including Belize, Guatemala, Honduras, Nicaragua, Costa Rica, and western Panama. Its typical habitats include humid tropical forests, forest edges, secondary growth, plantations, and semi-open areas with scattered trees, often near water sources. It is commonly found from sea level up to around 1,200 meters in elevation, adapting well to disturbed and human-altered landscapes such as coffee plantations and gardens, though it avoids deep, undisturbed primary forest interiors.

Comportements & Reproduction

The scarlet-rumped tanager is highly social, often foraging in mixed-species flocks and living in loose, non-territorial groups. During the breeding season, males engage in competitive displays, including spreading their vivid red rump feathers and performing short, fluttering flights to attract females. Mating pairs form a strong bond for the season, with both sexes cooperating to build a cup-shaped nest in dense foliage, typically 2–6 meters above ground. The female lays two to three pale blue eggs with brown speckles, and both parents share incubation duties over 12–14 days. A unique reproductive strategy is their occasional use of old nests from other bird species, saving energy on construction. After hatching, the chicks are fed insects and fruit by both parents, fledging after about 12–15 days, and the pair may raise two broods per season in favorable conditions.

Alimentation

The Scarlet-rumped Tanager is primarily frugivorous, with fruits making up the vast majority of its diet, especially small berries, figs, and other soft fruits from trees and shrubs. It is also an opportunistic insectivore, actively gleaning insects, spiders, and other arthropods from leaves and bark, particularly during the breeding season to meet higher protein demands for chick development. An interesting fact about its feeding behavior is that it often forages in mixed-species flocks, following army ant swarms to catch insects flushed by the ants, and it will occasionally visit feeders for papaya or banana when available in its lowland and foothill habitats.

Couleurs

The male Scarlet-rumped Tanager has velvety black plumage on its head, back, wings, and tail, contrasted by a brilliant crimson or deep scarlet rump and lower back. The female is olive-brown above with a paler yellowish throat and breast, and a duller orange-red rump. Both sexes have a pale blue-gray bill with a dark tip. Their coloration is not cryptic; the male’s striking contrast serves for display, while the female’s duller tones offer some camouflage in foliage.