Salvadori's Nightjar vs Heinrich's Nightjar

Churring trill; repetitive 'chrrr' from Sumatran highland forest; calls at night from mossy forest understory; moderate pitch; similar to but separable from Bornean species

Haunting, hollow 'ku-WOO' repeated rhythmically; deep resonant quality; distinctive mournful whistle carrying through Sulawesi forest at night

Attractively patterned dark brown and buff upperparts; warm buff supercilium and throat patch; rufous-buff spotting on wing coverts; underparts barred buff; montane Sundaland endemic with relatively rich coloration.

Rufous-brown and dark brown mottled with buff vermiculations; large pale buff throat patch; pale buff supercilium; no white wing markings; tail darkly barred brown and buff. Poorly known; Sulawesi endemic.