Ontogeny of vocalizations in tree shrews ( Tupaia belangen ) from birth to 2 months of age was studied by acoustic and video recording of behavior in captive family groupings. Sounds produced by nestlings were infrequent, of relatively low intensity, and included occasional clicks and waks, rapidly produced clicks that merged into purring during suckling, infrequent distress whimpers, some precursors to adult chatter series vocalizations, and a defensive snort also heard from adults. An immature form of chattering was heard late in the nestling phase. The remainder of the adult repertoire appeared upon departure from the nestbox. The suppression of vocalization in the nestling phase functions in concert with parental avoidance of the nestbox to thwart predation.