River Tyrannulet

Serpophaga hypoleuca

The River Tyrannulet (Serpophaga hypoleuca) is a diminutive and engaging flycatcher, embodying the active, restless nature of its family. Measuring a mere 10-11 cm (approx. 4 inches) in length and weighing 7-9 grams, this small passerine features a sleek, grayish-olive back, contrasting with pure white underparts-a key identification feature reflected in its scientific epithet 'hypoleuca,' meaning 'white below.' Distinctive field marks include a thin white supercilium above a dark eye-stripe,...

Habitat

Found exclusively in lowland riparian zones, the River Tyrannulet favors river islands, sandy or muddy banks, and the edges of 'várzea' (seasonally flooded) and gallery forests, generally below 500 meters elevation.

Diet

The River Tyrannulet is primarily insectivorous, consuming small invertebrates such as flies, mosquitoes, beetles, and caterpillars. It forages by sallying, gleaning, and hover-gleaning from low vegetation over or near water.

Behavior

This active, restless flycatcher is predominantly diurnal, spending its days darting among low vegetation near water. Its foraging strategy involves agile aerial maneuvers; it frequently sallies out from a low perch to hawk insects in mid-air, gleans them from leaves and twigs with quick movement...

Range

The River Tyrannulet is a resident species found across a significant portion of lowland South America, primarily within major river basins. Its core range spans Brazil, extending throughout the Amazon Basin from Amazonas state south through Rondônia, Mato Grosso, Goiás, and Minas Gerais, reachin...

Conservation Status

Least Concern

Fun Facts

- Its scientific name 'hypoleuca' literally means 'white below,' perfectly describing its prominent ventral plumage. - This diminutive bird often bobs and fans its tail, a common trait among many flycatcher species, though its exact purpose is still debated. - Despite its small size, it belongs t...

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