En bref

• Scientific Name: Sporophila plumbea
• Spanish Name: Semillero plomizo
• Famille : Thraupidae
• Known Nicknames: Plumbeous Seedeater
• Average Length: 10–11 cm / 3.9–4.3 in
• Poids moyen : 9 à 12 g / 0,32 à 0,42 oz
• Envergure : N/A
• Key Feature: Slate-gray plumage with a pale bill and white wing speculum
• Primary Diet: Granivore
• Range: Northern South America, from Colombia and Venezuela to the Guianas, Brazil, and northern Bolivia
• Habitat: Grasslands, savannas, and open areas with tall grass
• Social Structure: Often seen in small flocks or pairs
• Nesting/Breeding: Cup-shaped nest in low bushes or grass tussocks
• Statut de conservation : Préoccupation mineure (LC)
• Évolution démographique : Stable

The Plumbeous Seedeater (*Sporophila plumbea*) is a small, striking finch native to South America’s grasslands and savannas, renowned for its stark sexual dimorphism. Males are a sleek, uniform slate-gray with a distinctive white patch at the base of the primary wing feathers and a pale, conical bill perfectly adapted for cracking grass seeds. Females, in contrast, are a warm, unstreaked brown, offering cryptic camouflage. A unique characteristic of this species is the male’s “whisper song”—a soft, intricate warble often delivered from a hidden perch, which contrasts with its otherwise plain appearance. Special features include a strong preference for seeding grasses like *Paspalum*, making it a key indicator of healthy, undisturbed open habitats, and its highly social nature, often foraging in small flocks that can be heard before they are seen.

Faits amusants

Despite its drab, slate-gray plumage, the male plumbeous seedeater has a surprisingly complex song, incorporating mimicked calls from other bird species to attract mates and defend territory. These finches exhibit a quirky "seed-husking" behavior where they rapidly roll a seed between their mandibles to eject the outer shell, sometimes discarding up to 20 husks per minute. A unique adaptation is their specialized, conical bill with a sharp, slightly curved tip that acts like a precision nutcracker, allowing them to crack open tough grass seeds that other finches cannot process. During the non-breeding season, they form large, nomadic flocks that perform synchronized, swirling flight displays, often mistaken for a cloud of insects at a distance.

Habitats et répartition

The Plumbeous Seedeater primarily inhabits open and semi-open landscapes, including grasslands, savannas, scrubby pastures, agricultural fields, and disturbed areas with tall grasses and scattered bushes. It is often found near water sources such as rivers and marshes, and it avoids dense forests. Its geographical range spans central and eastern South America, from central and eastern Brazil south through Paraguay and northeastern Argentina, with isolated populations also occurring in Bolivia and northeastern Peru.

Comportements & Reproduction

The Plumbeous Seedeater is typically monogamous during the breeding season, with males establishing and defending small territories through persistent song displays from exposed perches. Courtship involves the male performing a fluttering, butterfly-like flight while singing, often while carrying a grass stem or leaf to present to the female as a nest-building invitation. Social structure is generally solitary or in loose pairs outside of breeding, though they may join mixed-species foraging flocks during non-reproductive periods. A unique reproductive strategy is their reliance on constructing a tightly woven, cup-shaped nest of fine grasses and spiderwebs, often placed in low shrubs or grass clumps near water, which helps conceal the clutch of 2-3 eggs from predators. The female incubates alone for about 12-13 days, but both parents feed the altricial young, which fledge after roughly 10-12 days.

Alimentation

The Plumbeous Seedeater is, as its name suggests, a specialist granivore, with seeds forming the overwhelming majority of its diet. It primarily forages on the ground or in low grasses and shrubs, meticulously picking small seeds from plants such as grasses, sedges, and various weeds. An interesting aspect of its feeding behavior is its strong preference for soft, immature seeds over hard, dry ones, which it can often be seen extracting directly from the seed heads before they fully ripen. During the breeding season, adults will occasionally supplement their diet with small insects and spiders to provide essential protein for their growing chicks, though seeds remain the staple even then.

Couleurs

The male Plumbeous Seedeater is a uniform slate-gray with a pale whitish belly, a distinctive white patch on the wing (speculum), and a black bill. Females are dull brownish above and buff below, lacking the male’s wing patch. The species shows no camouflage adaptation, but the male’s gray plumage blends with shaded forest edges and grasslands.

Distribution Map

Places linked to this species. A sighting is never guaranteed.

Détails de l'attraction

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