Pachycephala simplex Gould, 1843

Nominate race has off- white supercilium from side of forehead to above eye and broken eyering, greyish- brown lores and ear- coverts; neck side and upperparts olive- brown, upperwing grey- brown, primaries and greater primary coverts edged pale brown; tail dark olive- brown, rectrices edged paler; off- white below, chin and throat faintly streaked light brown, breast washed with with brown, sometimes with darker streaking; iris reddish- brown; bil and legs black. Sexes alike. Juvenile is rufous, underparts paler and lighter, remiges, rectrices and primary coverts edged rufous, secondary coverts rufous; immature like adult, but retains juvenile remiges and primary coverts, has paler bill. Races differ mainly in plumage tones, amount of yellow in plumage (present in all except first following), and degree of streaking bellow: dubia is like nominate ( i.e. lacks yellow pigment), but upperparts deeper brown, throat more heavily streaked, breast and flanks washed rufous- brown; waigeuensis has back olive, streaks on throat faint, breast without brown wash, belly pale yellow; gagiensis is like previous but slightly larger; jobiensis is also similar, but belly brighter yellow; griseiceps is also similar but breast has brownish wash, ear- coverts browner; perneglecta is like is like previous but with heavier streaking on throat; sudestensis is same as last in plumage, but larger and with longer bill; peninsulae is similar to previous two, bur upperparts not so deeply coloured, throat less heavily streaked, wash on breast reduced; rufipennis is like griseiceps but lack less olive, belly whiter; miosnomensis is larger, wits wing longer.