Responding to forest degradation: altered habitat use by Dian's tarsier Tarsius dianae in Sulawesi, Indonesia

Abstract

As most of the pristine forests of South-east Asia have been lost, the ability of its animal species to coexist with humans becomes increasingly important. Dian's tarsier Tarsius dianae, one of the smallest primates, lives in forests of central Sulawesi, Indonesia that are experiencing a dramatic increase in degradation by humans. To evaluate the effects of anthropogenic disturbance on tarsiers we used a comprehensive approach to estimate habitat suitability for these nocturnal insecthunters. On four study plots along a gradient of human land-use we determined population densities, home range sizes, nightly path lengths and group sizes of T. dianae. In total we captured 71 individuals and radio-tracked 30 of these. In more undisturbed sites, population densities were high and travel distances small. We found the smallest home ranges in slightly disturbed forest. In a heavily disturbed plantation densities were low, and ranges and nightly path lengths were large. These results show that undisturbed and slightly degraded forests are the most suitable tarsier habitats, and that focusing on different population parameters could lead to differing conclusions about the suitability of particular habitats.

Elucidating geological and biological processes underlying the diversification of Sulawesi tarsiers

“…We captured 2 males with T. lariang-typic genetic signatures several hundred meters outside of their species' usual range. This observation falls into a radius that tarsiers easily cover within a single night (42,47). Although these 2 individuals might also have been translocated and released pets, the steep gradients in allele frequencies at the species boundary and the consistent lack of alien genes in the reference populations suggest that accidental introductions do not play an important role in shaping the genetic structure of tarsier populations in a human-altered landscape.…”

“…This interspecific difference could be a signature of a more recent population expansion of Dian's tarsiers to populate the eastern areas of central Sulawesi. Judging from this species' wide distribution (41), its adaptability to human land use (42), and the presumed displacement of T. lariang by T. dentatus in parts of its range (see below), Dian's tarsier appears to be a good disperser and probably the more opportunistic of the 2 species.…”

Living together in the night: abundance and habitat use of sympatric and allopatric populations of slow lorises and tarsiers

“…An important limitation for lorises is that they are quadrupedal and are incapable of leaping, thus requiring canopy continuity to move easily throughout the forests, although they can move on Merker et al 2005). Populations in anthropo genically modified areas are considerably lower compared with other populations (Merker et al 2005). Such requirements pose a challenge for tarsiers when confronted with environmental and ecological changes.…”

“…Past studies on slow lorises have found that they occupy numerous types of environment, from plantations and other agricultural areas to heavily degraded forests and pristine forests (Elliot & Elliot 1967, Wiens & Zitzmann 2003, Radhakrishna et al 2006). An important limitation for lorises is that they are quadrupedal and are incapable of leaping, thus requiring canopy continuity to move easily throughout the forests, although they can move on Merker et al 2005). Populations in anthropo genically modified areas are considerably lower compared with other populations (Merker et al 2005).…”

Characterization of the Tree Holes Used by Lepilemur ruficaudatus in the Dry, Deciduous Forest of Kirindy Mitea National Park

“…A major goal of primatology is to document important primate resources and to understand how these resources influence primate behavior and population dynamics [e.g., Merker et al, 2005;Irwin, 2008;Fish, 2014;Chapman et al, 2015]. Most research focuses on food resources [e.g., Ganzhorn et al, 2004;Balko and Underwood, 2005;Joly and Zimmermann, 2007;Yamashita et al, 2010].…”