Family Reed-warblers (Acrocephalidae)

Critically Endangered

Millerbird (Acrocephalus familiaris)


French: Rousserolle obscure German: Hawaiirohrsänger Spanish: Carricero familiar

Tatare familiaris


, 1892,

Laysan Island, Hawaii


Race kingi sometimes treated as a full species because of morphological and genetic#R differences. Nominate race (restricted to Laysan) extinct. One extant subspecies recognized.

Subspecies and Distribution
  • A. f. familiaris (Rothschild, 1892) – Laysan Millerbird – Laysan, in NW Hawaiian Is.
  • A. f. kingi (Wetmore, 1924) – Nihoa Millerbird – Nihoa, in W Hawaiian Is.
  • Descriptive notes

    13 cm; 15–21·5 g (mean c. 18·3 g). Small and drab, thin-billed warbler. Nominate race extinct. Race kingi has lores whitish with some olive tips... read more


    Song, from exposed perch, rather simple and short, described as thin, metallic and energetic. Calls... read more


    Bushy hillsides; prefers dense cover near ground, particularly around the shrubs Chenopodium... read more

    Food and feeding

    Diet chiefly insects and their larvae, especially moths and caterpillars (Lepidoptera, including large miller moths of family Noctuidae),... read more


    Season at least Jan–Sept. Monogamous. Nest built by both sexes, taking up to 2 weeks, a fairly deep cup (not so deep as nests of most... read more



    Status and conservation

    CRITICALLY ENDANGERED. Restricted-range species: present in Laysan Island EBA (Extinct) and in Nihoa Secondary Area. Nominate race was confined to Laysan I, where estimated... read more

    Recommended citation

    Dyrcz, A., de Juana, E. & Sharpe, C.J. (2019). Millerbird (Acrocephalus familiaris). 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 22 April 2019).