Family Tyrant-flycatchers (Tyrannidae)

Least Concern

Guianan Tyrannulet (Zimmerius acer)


French: Tyranneau vif German: Guayanakleintyrann Spanish: Mosquerito guayanés

Tyranniscus acer

Salvin and Godman

, 1883,

Bartica Grove, Guyana


Formerly treated as a full species, but in recent years lumped with Z. gracilipes until molecular analysis#R corroborated separation. Differs from gracilipes in its almost pure white face and lower throat (1); paler yellow underparts (1); and notes (one or two) of daytime call (falling “chu-chup” or “chup” vs rising “wheet” or “whit”) being very short (ns[1]), decreasing in pitch (3), with higher maximum frequency (2) and very different shape (ns[1])#R. Populations on N side of Amazon give “chu-chup” call, those on S side give “chup”, suggesting presence in latter of an unnamed taxon. Monotypic.

What do (1) and (2) mean? Learn more about the scoring system.

E & SE Venezuela, the Guianas and NE Brazil (E Amazonas S to N Mato Grosso, E to Maranhão, Ceará and Alagoas).

Descriptive notes

9–11·4 cm; 5·7–11 g. Very similar in size, structure and plumage to formerly conspecific Z. gracilipes, but has almost pure white face and lower throat, as well as... read more


Dawn song a fast series of cricket-like notes, “tueet, tue’re’RE!...tueet, tue’re’RE!..” or an... read more


Humid lowland evergreen forest (including both terra firme and várzea) and forest... read more

Food and feeding

Diet insects and small fruits. No differences known from formerly conspecific Z. gracilipes.


Season almost unknown, but eggs taken in Sept in Suriname. Nest (Guyana) a rounded dome with a side entrance, placed high in a mango tree,... read more



Status and conservation

Not globally threatened (Least Concern). Uncommon to common, albeit often overlooked due to canopy-dwelling habits, being located mainly by voice. Occurs in many national... read more

Recommended citation

del Hoyo, J., Collar, N. & Kirwan, G.M. (2020). Guianan Tyrannulet (Zimmerius acer). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved from on 17 January 2020).