Family Tanagers (Thraupidae)

Vulnerable

Inaccessible Finch (Nesospiza acunhae)


Taxonomy

French: Nésospize de Tristan da Cunha German: Tristanammertangare Spanish: Yal de la Inaccesible
Taxonomy:

Nesospiza Acunhae

Cabanis

, 1873,

Tristan da Cunha

.

Nominate race and fraseri formerly considered conspecific with N. questi of Nightingale I, but genetic evidence suggests independent evolution on each island. Races of present species breed assortatively in coastal habitats, where large-billed dunnei and small-billed, drab nominate race behave as distinct species (distinct songs, and territorial behaviour focused primarily on members of own race); in contrast, all three races interbreed in ecotone between Blechnum heath and Phylica woodland on the island’s plateau. Three subspecies recognized.

Subspecies and Distribution
  • N. a. acunhae Cabanis, 1873 – coastal scarps of Inaccessible I, in S Atlantic.
  • N. a. fraseri Ryan, 2008 – plateau of Inaccessible I.
  • N. a. dunnei Hagen, 1952 – coast and E plateau of Inaccessible I.
  • Descriptive notes

    17–21 cm; 24–49 g. An exceptionally variable species. Male nominate race is olive-green above and paler olive-grey below, with yellowish forecrown and throat;... read more

    Voice

    Male song a repeated phrase of 3–4 notes, “whit it teeu”, more varied than that... read more

    Habitat

    Nominate race largely confined to coastal lowlands and cliffs dominated by Spartina arundinacea... read more

    Food and feeding

    Diet mainly seeds, fruits and invertebrates. Small-billed nominate race eats seeds of Spartina and other grasses, sedges and forbs... read more

    Breeding

    Season Nov–Feb; single-brooded. Usually monogamous, and partners remain together for successive breeding attempts; one male of... read more

    Movements

    Mostly resident. Some immatures of race fraseri apparently forage along coast in winter,... read more

    Status and conservation

    VULNERABLE. Restricted-range species: present in Tristan Islands EBA. Abundant and widespread on Inaccessible I (14 km²), with estimated 10,000 pairs. Population of... read more

    Recommended citation

    Ryan, P. (2018). Inaccessible Finch (Nesospiza acunhae). 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 https://www.hbw.com/node/62040 on 19 October 2018).