Northern pigtailed macaques rely on old growth plantations to offset low fruit availability in a degraded forest fragment

Space‐use and foraging strategies are important facets to consider in regard to the
ecology and conservation of primates. For this study, we documented movement,
ranging, and foraging patterns of northern pigtailed macaques (Macaca leonina) for
14 months in a degraded habitat with old growth Acacia and Eucalyptus plantations
at the Sakaerat Biosphere Reserve in northeastern Thailand. We used hidden
Markov models and characteristic hull polygons to analyze these patterns in regard
to fruit availability. Macaques' home range (HR) was 599 ha and spanned through a
natural dry‐evergreen forest (DEF), and plantation forest. Our results showed that
active foraging increased with higher fruit availability in DEF. Macaques changed to
a less continuous behavioral state during periods of lower fruit availability in DEF,
repeatedly moving from foraging to transiting behavior, while extending their HR
further into plantation forest and surrounding edge areas. Concomitantly, macaques
shifted their diet from fleshy to dry fruit such as the introduced Acacia species. Our
results showed that the diet and movement ecology adaptations of northern pigtailed
macaques were largely dependent on availability of native fruits, and reflected
a “high‐cost, high‐yield” foraging strategy when fresh food was scarce and dry fruit
was available in plantation forest. Conversely, wild‐feeding northern pigtailed macaque
populations inhabiting pristine habitat approached a “low‐cost, low‐yield”
foraging strategy. Our results outline the effects of habitat degradation on foraging
strategies and show how a flexible species can cope with its nutritional
requirements.