Pearled treerunner (Margarornis squamiger) is a species of bird in the Furnariinae subfamily of the ovenbird family Furnariidae. It is found in Bolivia, Colombia, Ecuador, Peru, Venezuela, and Argentina.

Dec 28, 2024

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Pearled Treerunner / Margarornis squamiger / Corretroncos … | Flickr

Adults of the nominate subspecies have a well-defined yellowish buff supercilium that extends to the nape, a dull reddish brown line behind the eye, dull yellowish buff and dark brown ear coverts, and a dark brown moustacial area with tiny whitish spots that become streaks to the rear. Their forehead is dark brownish with pale rufous streaks and their crown dark reddish brown. Their collar is dull rufescent brown with black-outlined yellowish buff streaks. Their back, rump, and uppertail coverts are bright reddish brown.

Their wing coverts are bright reddish brown, their primary coverts dark fuscous brown, and their flight feathers darker fuscous brown with rufescent edges. Their tail is bright reddish brown; the ends of the tail feathers lack barbs, giving a spiny appearance. Their throat is bright buff-yellow. Their breast and belly have a rufescent background. Their upper breast is dense with oval yellowish spots that have dark browish outlines; the spots become stretched out and less distinct by the lower breast and continue onto the belly. Their flanks are darker rufescent than the belly, with longer spots, and their undertail coverts are rufescent brown with a few blackish-edged buff-yellowish streaks. Their iris is brown to dark brown.

Pearled Treerunner (Margarornis squamiger)

Order: Passeriformes | Family: Furnariidae | IUCN Status: Least Concern

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Age: Adult | Sex: Unknown | Loc. Alto Nieva, San Martin

pearled_treerunner
Age: Adult | Sex: Unknown | Loc. Eastern Andes of Colombia

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Age: Adult | Sex: Unknown | Loc. Acjanaco, Cuzco

pearled_treerunner
Age: Adult | Sex: Unknown | Loc. Alto Nieva, San Martin

Identification & Behavior: ~15 cm (6 in). The Pearled Treerunner has a rufous-brown head with a buffy surpercilium and streaks on the sides of the head. The upperparts and tail are rufous. The throat is creamy-white. The underparts are spotted/streaked with whitish buff droplets fringed with black crating an ornate effect.Status: The Pearled Treerunner uncommon in montane forests of the east and west (Piura and Cajamarca) slopes of the Andes at elevations ranging between 2100-3700 m. It also occurs in Co, Ec, and Bo.

Name in Spanish: Subepalo Perlado.

Patricio Herrera Nature Photography. - Pearled Treerunner - Subepalo Perlado (Margarornis squamiger) | Facebook

Sub-species: Pearled Treerunner (Margarornis squamiger perlatus), Lesson, 1844. Perijá Mts and Andes of W Venezuela (Trujillo, Mérida, Táchira), Colombia (all three ranges), Ecuador, and N Peru N of R Marañón (Piura, N Cajamarca).
(Margarornis squamiger peruvianus), Cory, 1913. Andes of N & C Peru S of R Marañón (from S Cajamarca and Amazonas S to Cuzco).
(Margarornis squamiger squamiger), d’Orbigny and Lafresnaye, 1838. Andes of S Peru (Puno) and Bolivia (S to W Santa Cruz); sight record in NW Argentina (Salta).