Distribution and characteristics of the Makassar tarsius Tarsius fuscus fischer, 1804 sleeping nest in the tropical primary and secondary forests of South Sulawesi

Abstract

Tarsius fuscus, whose distribution is limited to the southern part of South Sulawesi, Indonesia, is threatened by poaching and habitat loss, with the latter leading to the disappearance of its sleeping nest locations, despite the species’ wide range of habitat requirements. This study aimed to identify the distribution and characteristics of T. fuscus sleeping nests. Research took place in Bantimurung Bulusaraung National Park primary and secondary forest areas and Hasanuddin University Educational Forest. Sleeping nest locations were identified through vocalizations in the morning (4.30–6.00 am) and direct visual observations. Sleeping nest distribution maps were created using QGIS 3.16. Sleeping nests were found in karst rock shelters, Ficus trees, forest pandanus, and fallen tree debris, at elevations of 68–947 mdpl, 4–42° slopes, temperatures ranging 23.3–29.1°C, and distances to roads and settlements of 21.4–460.3 m and 325.9–1888.5 m, respectively. Tarsius fuscus tended to nest in primary forest rather than secondary forest, although this may also be caused by the larger proportion of primary forest. Protecting both primary and secondary forest is crucial, but particular focus should be given to the latter, owing to its susceptibility to human disturbance.