Sarcelle à ailes bleues

En bref

Migratrice
  • Scientific Name: Spatula discors
  • Spanish Name: Cerceta aliazul
  • Famille : Anatidae
  • Known Nicknames: Blue-wing, Summer Teal
  • Average Length: 35–41 cm / 14–16 in
  • Average Weight: 250–450 g / 8.8–15.9 oz
  • Wingspan: 53–61 cm / 21–24 in
  • Key Feature: Blue forewing patch (speculum) bordered by white on the leading edge
  • Primary Diet: Primarily Herbivore (seeds, aquatic plants, some invertebrates)
  • Range: North America (breeds) to Central and South America (winters)
  • Habitat: Shallow freshwater wetlands, marshes, ponds, and rice fields
  • Social Structure: Social (forms flocks, especially during migration and winter)
  • Nesting/Breeding: Ground nest hidden in dense grass or sedges near water
  • Statut de conservation : Préoccupation mineure (LC)
  • Évolution démographique : En baisse

The Blue-winged Teal (*Spatula discors*) is a small, swift dabbling duck renowned for its striking seasonal plumage and remarkable migratory range. Males in breeding plumage are particularly distinctive, featuring a bold white crescent moon on the cheek set against a slate-blue head, a speckled brown body, and a prominent black rear end. The species' namesake feature is a powder-blue patch on the upper forewing, visible in flight, which contrasts sharply with a green speculum. A special trait is its early migration; among North American waterfowl, the Blue-winged Teal is one of the first to head south in autumn, often traveling in fast, tightly packed flocks that can cover vast distances to wintering grounds as far as South America.

Faits amusants

The Blue-winged Teal is one of the fastest ducks in North America, capable of reaching speeds up to 47 miles per hour, and it is also an early migrant, often leaving its breeding grounds by early September. A quirky behavior is its "puddle duck" feeding style: instead of diving, it tips forward like a floating seesaw to graze on shallow-water plants and invertebrates. It has a remarkable adaptation in its speculum—the iridescent green patch on its wing—which flashes brightly in flight, possibly to startle predators or signal to flock mates. Males perform a peculiar "hurtle" display during courtship, where they rapidly swim in tight circles around a female, puffing out their chests and whistling.

Habitats et répartition

The Blue-winged Teal inhabits shallow, freshwater wetlands, including marshes, ponds, lakes, and flooded fields, particularly those with dense emergent vegetation for cover and abundant aquatic invertebrates and seeds for foraging. It prefers open water areas interspersed with mudflats and grassy edges, and is also found in brackish marshes during migration and winter. Its breeding range spans much of the northern United States and southern Canada, with a core area in the Prairie Pothole Region. During migration, it moves through the central and eastern United States, wintering primarily in the southern United States, the Caribbean, Central America, and northern South America, reaching as far south as Brazil and Argentina.

Comportements & Reproduction

Blue-winged Teal exhibit a flexible social structure, often forming loose pairs during the breeding season that are maintained only until the female begins incubation. Males perform elaborate courtship displays, including head-pumping, whistled calls, and a distinctive "burp" sound, to attract females. They are typically monogamous for the season, but extra-pair copulations occur. A unique reproductive strategy is their high degree of nest site plasticity, choosing locations from dense grass to brush piles, often far from water. Females lay 6-14 eggs and incubate them alone for about 23-27 days, with males departing to form bachelor flocks shortly after egg-laying begins. The young are precocial, leaving the nest within 24 hours to feed themselves under the female's guidance, achieving flight at around 35-40 days old.

Alimentation

The Blue-winged Teal is primarily a dabbling duck that feeds on the surface of shallow waters, often by tipping forward to reach submerged plants and invertebrates. Its diet is seasonally variable, consisting mainly of seeds from aquatic plants like pondweeds, sedges, and grasses, complemented by a high proportion of animal matter during the breeding season. This animal matter includes aquatic insects such as midge larvae, caddisflies, and dragonfly nymphs, along with crustaceans like small crayfish and amphipods. An interesting fact is that the Blue-winged Teal is one of the most vegetarian of North American dabbling ducks, with plant material making up over 70% of its annual diet, and it often feeds at night to avoid competition with other ducks.

Couleurs

The male Blue-winged Teal has a slate-blue head with a bold white crescent in front of the eye, a brownish body with dark speckles, and a black rear end. Females are mottled brown overall with a pale eye ring. Both sexes display a pale blue patch on the forewing, bordered by white, which is highly visible in flight. Their cryptic brown and buff patterning provides excellent camouflage in marsh vegetation.