Understanding dietary diversity is a fundamental task in the study of stump-tailed macaque, Macaca arctoides in its natural habitat. However, direct feeding observation and morphological identification using fecal samples are not effective and nearly impossible to obtain in natural habitats because this species is sensitive to human presence. As ecological methods are challenging and time-consuming, DNA metabarcoding offers a more powerful assessment of the diet. We used a chloroplast tRNL DNA metabarcoding approach to identify the diversity of plants consumed by free-ranging M. arctoides in the Malaysia–Thailand border region located in Perlis State Park, Peninsular Malaysia. DNA was extracted from three fecal samples, and chloroplast tRNL DNA was amplified and sequenced using the Illumina MiniSeq platform. Sequences were analyzed using the CLC Genomic Workbench software. A total of 145 plant species from 46 families were successfully identified as being consumed by M. arctoides. The most abundant species were yellow saraca, Saraca thaipingensis (11.70%), common fig, Ficus carica (9.33%), aramata, Clathrotropis brachypetala (5.90%), sea fig, Ficus superba (5.44%), and envireira, Malmea dielsiana (1.70%). However, Clathrotropis and Malmea are not considered Malaysian trees because of limited data available from Malaysian plant DNA. Our study is the first to identify plant taxa up to the species level consumed by stump-tailed macaques based on a DNA metabarcoding approach. This result provides an important understanding on diet of wild M. arctoides that only reside in Perlis State Park, Malaysia.

No abstract

Banded langur (Presbytis femoralis) is an endangered leaf-eating colobine, found in Johor and Pahang in Malaysia. However, with less than 500 individuals reported to be surviving in Johor, their behaviour and ecology remain unknown among primatologists. This study provides the first systematic data on the daily activity budget of the species in Malaysia. Scan sampling technique was used to observe and record P. femoralis behaviour with 10 min interval starting from February 2018 to November 2018. The results are based on 186 h and 20 min of direct observation in the wild. The animals spent most of the time for resting (43 ± 13%) followed by moving (26 ± 9%), feeding (26 ± 7%), social activities (4 ± 3%), and others (1 ± 0%). Seasonality significantly influences the activity budget of the animals resulting in increased resting and moving in the non-fruiting season. Feeding activities decreased in the non-fruiting season compared with the fruiting season, whereas social activities remained the same. We concluded that the daily activity budget of P. femoralis in this study portrays comparable behavior to other langurs in Malaysia that would help in conservation and management of the species in terms of understanding temporal and spatial requirements of P. femoralis in a highly fragmented habitat.

The proboscis monkey, Nasalis larvatus, is an endemic species to the island of Borneo. It is listed in the IUCN Red List as Endangered with a decreasing population trend. Nevertheless, biological information, especially on the genetic diversity of the species, is still incomplete. Its fragmented distribution poses difficulties in gathering genetic samples along with its widespread distribution across Borneo. This study aims to determine the genetic variation and structure of N. larvatus with an emphasis on Malaysian Borneo populations to elucidate its gene flow. The genetic variation and structure of N. larvatus were examined using 50 sequences of the 1,434-bp cytochrome oxidase subunit I (COI) gene region of mitochondrial DNA. The COI sequences revealed low genetic variation among N. larvatus populations in Malaysian Borneo. This low genetic variability could be the result of inbreeding pressure that may have occurred due to the absence of population expansion in this species over the last 30,000 years. This is supported in our analysis of molecular variance, which showed that groups of N. larvatus are significantly differentiated possibly due to natural geographic barriers. This study provides baseline information on the genetic diversity among proboscis monkey populations in Borneo for the future genetic assessment of the species.