Relatively little is known about the behaviour of Dian’s tarsier, which was first described as recently as 1991. Tarsiers on Sulawesi live in small groups of up to eight individuals, consisting of one adult male, one to three adult females and their offspring (4). In the morning, a conspicuous duet song is often performed by the male and females at or close to the sleeping site (5), serving both as a territorial advertisement and to strengthen group bonds (4). Dian’s tarsier’s reproductive biology is poorly understood, but tarsiers are known to give birth to single young, and pregnant females of this species have been observed year-round (4). Other tarsier species experience gestation periods of around 180 days, after which mothers have been seen carrying the infant either under their belly or in their mouth (2) (5).
This arboreal species sleeps in a group in tree cavities (as in strangling figs) and dense foliage during the day (4) (6), and forages in the undergrowth during the night (4). Like other tarsiers, Dian’s tarsier is exclusively insectivorous and carnivorous (5), feeding mainly on insects such as crickets, grasshoppers and moths (4).