<trp-post-container data-trp-post-id='234463'>Olive-sided Flycatcher

En bref

Migratrice

• Scientific Name: Contopus cooperi
• Spanish Name: Pibí boreal
• Famille : Tyrannidae
• Known Nicknames: Three-beers bird, Cooper's Flycatcher
• Average Length: 18–20 cm / 7.1–7.9 in
• Average Weight: 28–37 g / 1.0–1.3 oz
• Wingspan: 31–35 cm / 12.2–13.8 in
• Key Feature: Dark olive-gray patches on the sides of the breast resembling a 'vest'
• Primary Diet: Insectivore (primarily Hymenoptera such as bees and wasps)
• Range: Breeds across North America (Alaska to Newfoundland, south through Western US); winters in Central and South America (primarily the Andes)
• Habitat: Coniferous forest edges, montane forests, and burned areas with standing snags
• Social Structure: Solitary and territorial
• Nesting/Breeding: Nests placed high in coniferous trees on horizontal branches
• Statut de conservation : Quasi menacé (NT)
• Évolution démographique : En baisse

The Olive-sided Flycatcher (*Contopus cooperi*) is a master of the forest canopy, easily identified by its distinctive "vested" appearance—dark, brownish-olive plumage on its flanks that contrasts sharply with a clean white streak down the center of its breast. This stout, large-headed songbird is most famous for its ringing, three-note whistle that sounds like "Quick, three beers!", often delivered from the highest, skeletal snags of coniferous trees. A specialist in aerial acrobatics, it employs a "hawking" hunting style, darting from its high perch to snatch large flying insects mid-air with an audible snap of its beak before returning to the same lookout. Beyond its bold silhouette and iconic call, this remarkable bird is one of North America’s longest-distance migrants, traveling thousands of miles each year between the northern boreal forests and the distant slopes of the Andes Mountains.

Faits amusants

This bird is most famous for its loud, distinctive song that sounds remarkably like the phrase "Quick, three beers!" Often seen perched atop the highest "snag" or dead tree in the forest, it acts as a feisty sentinel, aggressively dive-bombing much larger intruders like hawks and crows to defend its territory. It undertakes one of the longest migrations of any North American flycatcher, traveling up to 7,000 miles to reach the Andes Mountains. Additionally, it is a specialized "bee-eater" that frequently snatches stinging insects mid-air, often rubbing them against a branch to remove the stinger before swallowing its meal.

Habitats et répartition

This species primarily inhabits coniferous and mixed-evergreen forests, showing a distinct preference for forest edges and openings near water, such as bogs, meadows, and lakes. It is frequently found in disturbed landscapes, including recently burned areas or clear-cuts, where tall, dead trees (snags) provide essential perching sites for hunting and nesting. These open-canopy environments are critical, as they allow for the unobstructed aerial maneuvers required for its foraging behavior.

Its breeding range spans the boreal forests of Alaska and Canada, extending southward into the western United States and parts of the Northeast. As a long-distance migrant, it travels through Central America to reach its wintering grounds in South America. During the non-breeding season, it is typically found in the montane forests of the Andes and the edges of the Amazon basin, maintaining its reliance on forest clearings and high-altitude woodlands.

Comportements & Reproduction

Highly territorial and typically solitary outside of the breeding season, these birds are frequently observed perched atop the highest dead snags of coniferous trees. From these vantage points, they aggressively defend large territories against intruders, including much larger raptors, while using their distinct "quick, three beers" call to signal their presence. During the breeding season, they form monogamous pairs. The female is primarily responsible for constructing the cup-shaped nest, which is typically situated far out on a horizontal branch, often high above the ground to avoid terrestrial predators.

Mating begins shortly after they arrive at their northern breeding grounds following an extensive long-distance migration. The female typically lays a clutch of three to four eggs and handles the majority of the incubation duties. Once the eggs hatch, both parents participate in feeding the young a diet consisting almost exclusively of flying insects. A unique reproductive strategy of this species is its strong ecological association with disturbed forest habitats, particularly those affected by fire or selective logging; the resulting standing snags provide essential nesting sites and clear lines of sight for both foraging and territorial defense.

Alimentation

The Olive-sided Flycatcher is an obligate insectivore with a highly specialized diet that primarily consists of large flying insects, most notably bees, wasps, and winged ants from the order Hymenoptera. Utilizing a hunting strategy known as "hawking," this bird perches prominently on high, exposed dead branches to scan the surroundings before launching into the air to intercept prey with agile, acrobatic maneuvers. An interesting aspect of its feeding behavior is its strong site fidelity; it frequently returns to the exact same "snag" or lookout point after each successful capture to consume its meal. While its preference for Hymenoptera is distinct, it also opportunistically consumes dragonflies, beetles, moths, and flies, yet it remarkably avoids almost all plant matter and non-flying invertebrates, making it one of the most specialized aerial foragers among North American flycatchers.

Couleurs

The Olive-sided Flycatcher features dark olive-gray upperparts and heavy, dark-streaked flanks that create a distinctive "vested" appearance over a white throat and belly. This bicolored pattern, often accented by white tufts on the rump and a pale-based lower mandible, provides excellent camouflage among the shadows and snags of coniferous forests.