A long-tailed bird of montane forest canopy. Male has much longer tail with iridescent green belly, black chest and small, iridescent blue throat patch. Female is blackish with indistinct barring on the belly. Feeds on fruit and searches for insects on mossy branches and epiphytes. Somewhat similar to Black Sicklebill but Arfak Astrapia lacks the long, curved bill. Call, a relatively low “clup!” that sounds somewhat like banging 2 large stones together.