Acanthizidae – Australasian Warblers

Tasmanian Thornbill Acanthiza ewingii ©Ian Montgomery Website

The Acanthizidae, also known as the Australasian warblers, are a family of passerine birds, which include gerygones, thornbills, and scrubwrens. The Acanthizidae consists of small to medium passerine birds, with a total length varying between 8 and 19 centimetres. They have short rounded wings, slender bills, long legs, and a short tail. Most species have olive, grey, or brown plumage, although some have patches of a brighter yellow. The smallest species of acanthizid, and indeed the smallest Australian passerine, is the weebill, the largest is the pilotbird.

Acanthizids are native to Australia, Indonesia, New Zealand, and the south-west Pacific. Most species are found in Australia and New Guinea, with Australia having thirty-five endemic species and New Guinea fifteen. A single species is found in Vanuatu, New Caledonia and the Solomon Islands, and three species occur in the New Zealand region, including endemic species in the Chatham Islands and Norfolk Island. In Asia two species are restricted to Indonesia and another is found in the Philippines and on mainland Asia. Most species are sedentary, with the exception of the gerygones. The family occupies a range of habitats from rainforests to arid deserts.

Most species are terrestrial, feeding primarily on insects, although also eating some seeds. In particular the whitefaces consume large numbers of seeds, and other species will take fruits. The secretions of sap-sucking insects are favoured by some species, as are the insects themselves. Some species are less terrestrial, such as the weebill, which forages in the treetops, or the rock-dwelling rockwarbler.

Rainforest species lay one to two eggs in a clutch, and species in the deserts and Tasmania lay three to four. Acanthizids are unusual for passerines in their long incubation periods, which rival those of large songbirds like the Corvidae. Also, despite their long incubation period hatching is completely synchronous and within-brood mortality completely absent.

Acanthizids are relatively long-lived, with many species living to over ten years of age in the wild and cooperative breeding is found in the weebill and with a lesser degree of development in all whitefaces and most species of Sericornis and Acanthiza.

There are generally agreed to be the following 65 species in this group:

Goldenface Pachycare flavogriseum

Fernwren Oreoscopus gutturalis

Pilotbird Pycnoptilus floccosus

Scrubtit Acanthornis magna

Rockwarbler Origma solitaria

Chestnut-rumped Heathwren Calamanthus pyrrhopygius
Shy Heathwren Calamanthus cautus
Striated Fieldwren Calamanthus fuliginosus
Western Fieldwren Calamanthus montanellus
Rufous Fieldwren Calamanthus campestris

Redthroat Pyrrholaemus brunneus
Speckled Warbler Pyrrholaemus sagittatus

Rusty Mouse-warbler Crateroscelis murina
Bicolored Mouse-warbler Crateroscelis nigrorufa
Mountain Mouse-warbler Crateroscelis robusta

Pale-billed Scrubwren Sericornis spilodera
Papuan Scrubwren Sericornis papuensis
Atherton Scrubwren Sericornis keri
White-browed Scrubwren Sericornis frontalis
Tasmanian Scrubwren Sericornis humilis
Yellow-throated Scrubwren Sericornis citreogularis
Large-billed Scrubwren Sericornis magnirostra
Tropical Scrubwren Sericornis beccarii
Perplexing Scrubwren Sericornis virgatus
Large Scrubwren Sericornis nouhuysi
Buff-faced Scrubwren Sericornis perspicillatus
Vogelkop Scrubwren Sericornis rufescens
Grey-green Scrubwren Sericornis arfakianus

Weebill Smicrornis brevirostris

Brown Gerygone Gerygone mouki
Grey Gerygone Gerygone igata
Norfolk Gerygone Gerygone modesta
Lord Howe Gerygone Gerygone insularis
Chatham Gerygone Gerygone albofrontata
Fan-tailed Gerygone Gerygone flavolateralis
Brown-breasted Gerygone Gerygone ruficollis
Golden-bellied Gerygone Gerygone sulphurea
Rufous-sided Gerygone Gerygone dorsalis
Mangrove Gerygone Gerygone levigaster
Plain Gerygone Gerygone inornata
Western Gerygone Gerygone fusca
Dusky Gerygone Gerygone tenebrosa
Large-billed Gerygone Gerygone magnirostris
Biak Gerygone Gerygone hypoxantha
Yellow-bellied Gerygone Gerygone chrysogaster
Green-backed Gerygone Gerygone chloronota
White-throated Gerygone Gerygone olivacea
Fairy Gerygone Gerygone palpebrosa

Mountain Thornbill Acanthiza katherina
Brown Thornbill Acanthiza pusilla
Inland Thornbill Acanthiza apicalis
Tasmanian Thornbill Acanthiza ewingii
New Guinea Thornbill Acanthiza murina
Chestnut-rumped Thornbill Acanthiza uropygialis
Buff-rumped Thornbill Acanthiza reguloides
Western Thornbill Acanthiza inornata
Slender-billed Thornbill Acanthiza iredalei
Yellow-rumped Thornbill Acanthiza chrysorrhoa
Yellow Thornbill Acanthiza nana
Grey Thornbill Acanthiza cinerea
Striated Thornbill Acanthiza lineata
Slaty-backed Thornbill Acanthiza robustirostris

Southern Whiteface Aphelocephala leucopsis
Chestnut-breasted Whiteface Aphelocephala pectoralis
Banded Whiteface Aphelocephala nigricincta

Number of Species
  • Number of bird species: 65

Fatbirder - linking birders worldwide... Wildlife Travellers see our sister site: WAND