Temporal activity patterns suggesting niche partitioning of sympatric carnivores in Borneo, Malaysia

Miyabi Nakabayashi,Augustine Tuuga,Henry Bernard,Abdul Hamid Ahmad,Ikki Matsuda,Goro Hanya,Peter T Malim,Joseph Tangah,Tomoko Kanamori,Aoi Matsukawa

doi:10.1038/s41598-021-99341-6

Abstract

To propose proper conservation measures and to elucidate coexistence mechanisms of sympatric carnivore species, we assessed temporal activity patterns of the sympatric carnivore species using 37,379 photos collected for more than 3 years at three study sites in Borneo. We categorized activity patterns of nine carnivore species (one bear, three civets, two felids, one skunk, one mustelid, one linsang) by calculating the photo-capturing proportions at each time period (day, night, twilight). We then evaluated temporal activity overlaps by calculating the overlap coefficients. We identified six nocturnal (three civets, one felid, one skunk, one linsang), two diurnal (one felid, one mustelid), and one cathemeral (bear) species. Temporal activity overlaps were high among the nocturnal species. The two felid species possessing morphological and ecological similarities exhibited clear temporal niche segregation, but the three civet species with similar morphology and ecology did not. Broad dietary breadth may compensate for the high temporal niche overlaps among the nocturnal species. Despite the high species richness of Bornean carnivores, almost half are threatened with extinction. By comparing individual radio-tracking and our data, we propose that a long-term study of at least 2 or 3 years is necessary to understand animals’ temporal activity patterns, especially for sun bears and civets, by camera-trapping and to establish effective protection measures.

Highlights

20% of the world’s mammal species face the risk of extinction, and this rate has become rapid mainly due to threats such as habitat loss and over exploitation[1]
To reduce the negative effects of competition, such as interspecific killing and to increase effective access to food resources, sympatric carnivore species flexibly change the temporal activity patterns for their temporal niche partitioning between 2 ≤ species with similar body size and/or utilizing similar-sized prey[7,8,9]
We captured 1261 photos of carnivores in total, and there were 753, 218, and 290 photos were taken in Danum Valley Conservation Area (DVCA), the Lower Kinabatangan Wildlife Sanctuary (LKWS), and Tabin Wildlife Reserve (TWR), respectively

Summary

Introduction

20% of the world’s mammal species face the risk of extinction, and this rate has become rapid mainly due to threats such as habitat loss and over exploitation[1]. The current information is too limited, and sporadic to understand their basic behaviors, such as temporal activity patterns, which may affect the progress in evaluating and improving the threatened status. This could be because many species of terrestrial carnivores are elusive and difficult to detect in general because of their naturally low d ensity[18]. Many studies on the temporal activity patterns of Bornean carnivores have been conducted These are mainly based on small sample sizes, collected in one site during limited periods, and focusing only on one or a few species. To evaluate the threatened status and species interactions, it is necessary to assess the temporal activity patterns of multiple species at multiple study sites is inevitable

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Conclusion