River Tyrannulet

Overview

The river tyrannulet (Serpophaga hypoleuca) is a small bird in the tyrant flycatcher family, Tyrannidae. It is found along two major South American river corridors in Bolivia, Brazil, Colombia, Ecuador, Peru, and Venezuela, and is assessed as Least Concern on the IUCN Red List.

Identification

• 10.5 to 12.5 cm long, weighing 5.5 to 6.7 g.
• White face with a black line through the eye, white lores, and a partial eye-ring.
• Black crown forming a flat crest, with brownish-gray upperparts and dusky brownish-gray wings.
• White chin, throat, and underparts, with a pale gray tinge across the breast.
• Dark brown iris, black bill, and dark gray legs and feet.
• Sings a series of high, hurried, happy-sounding twitters, and duets with its pair.

Habitat

The river tyrannulet has a disjunct distribution, found on river islands and mainland river edges in low-stature and sparse early-successional scrub. In eastern Colombia and western Venezuela, it occurs in scrubby and thorny areas along watercourses in the Llanos. It is generally found at elevations from sea level to 200 m, though locally up to 400 m in Ecuador.

Diet

The river tyrannulet feeds on insects, foraging alone, in pairs, or in family groups, actively and restlessly moving through shrubs and young trees. It captures prey mostly by gleaning while perched but also while briefly hovering after a short flight, and only rarely makes captures in flight.

Did you know?

The river tyrannulet weaves its nest from thin grass and spiderweb, and lines it with feathers, typically placing it in a fork between a branch and the main stem of a shrub about 0.5 m above the ground.