Family Herons (Ardeidae)

Least Concern

Least Bittern (Ixobrychus exilis)


French: Petit Blongios German: Amerikanische Zwergdommel Spanish: Avetorillo americano
Other common names: Cory’s Bittern (“I. neoxenus”)

Ardea exilis

J. F. Gmelin

, 1789,



Closely related to I. minutus, I. dubius and I. sinensis. Erythristic colour morphs (occur in nominate race and erythromelas) were described as a different species, I. neoxenus, although the notion that such birds represent even a morph has recently been disputed#R. Six subspecies normally recognized.

Subspecies and Distribution
  • I. e. exilis (J. F. Gmelin, 1789) – SE Canada and E USA, W USA S to Baja California (NW Mexico), also Central America and Caribbean; N populations winter S to Central America and West Indies.
  • I. e. pullus van Rossem, 1930 – NW Mexico (coastal S Sonora and Sinaloa).
  • I. e. erythromelas (Vieillot, 1817) – E Panama, N Colombia, N Venezuela, Trinidad and the Guianas to Bolivia, Paraguay, SE Brazil and NE Argentina (Corrientes).
  • I. e. bogotensis Chapman, 1914 – Andes of C Colombia (Antioquia, S Boyacá, Cundinamarca).
  • I. e. limoncochae D. W. Norton, 1965 – NE Ecuador and NE Peru, and perhaps S Colombia.
  • I. e. peruvianus J. Bond, 1955 – W Peru (mainly La Libertad to Lima).
  • Descriptive notes

    28–36 cm; 46·7–95 g. Adult male has blackish cap, buff to tawny-chestnut face- and neck-sides, white chin, throat and underparts, with buff-brown streaks... read more


    Considered to be rather vocal and may call throughout the day, at least in South America, but in... read more


    Usually dense freshwater marshes with reeds, sedges, cattails or sawgrass at margins of lakes,... read more

    Food and feeding

    Mainly small fish (Fundulus, Lepomis, Perca); also aquatic insects (grasshoppers, dragonflies), molluscs,... read more


    In N of range, laying Mar–Jul (including second and replacement clutches), becoming progressively later towards N, with season... read more


    Nominate exilis performs widespread post-breeding dispersal reaching as far afield as NE... read more

    Status and conservation

    Not globally threatened (Least Concern). In USA, declining in many areas, especially in W & SE, and considered threatened or of special concern in several states, but... read more

    Recommended citation

    Martínez-Vilalta, A., Motis, A. & Kirwan, G.M. (2020). Least Bittern (Ixobrychus exilis). 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 24 February 2020).