Swallow Tanager

Tersina viridis

Swallow Tanager - Minca, Magdalena, Colombia

Quick Facts

Migratory
  • Scientific Name: Tersina viridis
  • Spanish Name: Tersina
  • Family: Thraupidae
  • Known Nicknames: Tersina
  • Average Length: 14–15 cm / 5.5–6 in
  • Average Weight: 27–31 g / 0.95–1.1 oz
  • Wingspan: 28–30 cm / 11–12 in
  • Key Feature: Vibrant turquoise-blue plumage with a black face mask and throat in males; wide, swallow-like flat bill
  • Primary Diet: Primarily Frugivore and Insectivore
  • Range: South America, from Panama and Colombia to Northern Argentina and Southern Brazil
  • Habitat: Tropical and subtropical moist lowland forest edges, clearings, and gallery forests
  • Social Structure: Highly Social (gregarious, often seen in small flocks)
  • Nesting/Breeding: Burrows in earth banks, road cuts, or occasionally tree cavities
  • Conservation Status: Least Concern (LC)
  • Population Trend: Stable

The Swallow Tanager (*Tersina viridis*) is a striking Neotropical bird renowned for its vivid sexual dimorphism and specialized anatomy that sets it apart from other tanagers. Males are draped in a brilliant, shimmering turquoise-blue plumage accented by a velvet-black face mask and throat, while females sport a bright grass-green coat with yellow-barred flanks. True to its name, this species possesses an unusually broad, flat bill and long wings, enabling it to perform graceful, swallow-like aerial maneuvers to snap up insects mid-flight, though it primarily feeds on fruit. Beyond its dazzling colors, the Swallow Tanager is unique for its nesting behavior; unlike its tree-dwelling relatives, it is a cavity nester that often excavates burrows in earthen banks or utilizes holes in stone walls, making it one of the most ecologically distinct members of its family.

Fun Facts

Male Swallow Tanagers are striking for their shimmering turquoise feathers and "bandit mask" faces, while females remain camouflaged in bright green. True to their name, they hunt insects mid-air with the agility of a swallow, but they are also specialized fruit-eaters equipped with an exceptionally wide gape for swallowing large berries whole. Perhaps their most unusual quirk is their nesting habit; instead of building typical nests in branches, they are subterranean architects that excavate deep tunnels into earthen banks or occupy narrow crevices in stone walls.

Habitats & Distribution

This species occupies a vast geographical range across South America, extending from eastern Panama and Trinidad southward to northeastern Argentina, Paraguay, and Uruguay. It is widely distributed throughout the Amazon Basin, the Guianas, and the Atlantic Forest regions. While primarily a resident in many areas, some populations are known to undergo seasonal migrations, moving between breeding and non-breeding grounds within the continent. Its preferred habitats include the edges of humid forests, open woodlands, and clearings, often in close proximity to rivers or streams. It is highly adaptable and frequently occurs in disturbed environments such as plantations, orchards, and suburban parks. A key requirement for its habitat is the presence of vertical surfaces—such as earthen banks, cliffs, or even stone walls—which it utilizes for nesting. It is typically found at elevations ranging from sea level up to 1,600 meters.

Behaviours & Reproduction

These birds are highly social outside of the breeding season, often gathering in large, conspicuous flocks to forage for fruit and insects. They are known for their active nature, frequently perching on high, exposed branches and performing swallow-like aerial maneuvers to catch prey. During the breeding season, they form monogamous pairs and defend specific territories, though they may still congregate in communal feeding areas. Their reproductive strategy is unique among tanagers as they are specialized cavity nesters. The female constructs a cup-shaped nest at the end of a long tunnel, which she typically excavates in an earthen bank, cliffside, or even a hole in a building. She is solely responsible for incubating the two to three eggs, but once they hatch, both parents cooperate to feed the young a diet of regurgitated fruit and insects. This burrow-nesting habit provides exceptional protection from predators compared to the open-cup nests of most related species.

Diet

The Swallow Tanager maintains a diverse diet primarily composed of various small fruits and berries, supplemented significantly by insects. An interesting aspect of its feeding behavior is its ability to catch flying insects mid-air through a technique known as hawking, a trait that mirrors the behavior of true swallows and contributes to its common name. Anatomically, this bird possesses a remarkably wide gape, which enables it to consume fruits that are quite large relative to its body size by swallowing them whole. After digesting the fleshy pulp, the Swallow Tanager plays a vital role in its ecosystem by regurgitating the seeds, thereby acting as an effective agent for seed dispersal throughout its tropical habitat.

Colors

The male Swallow Tanager features a brilliant turquoise-blue plumage contrasted by a black face mask and throat, with a white lower belly and black-barred flanks. Females exhibit a bright grass-green coloration with yellowish, barred underparts that provide excellent camouflage within forest canopies. Both sexes possess short, broad black bills and dark wings, though the male’s vivid blue appears to shift in hue depending on the light.