Molecular Phylogenetic Status and Ecological Characteristics of Phayres Leaf Monkey (Trachypithecus phayrei) in Myanmar

Abstract

Phayres leaf monkey (Trachypithecus phayrei) is a medium sized primate and endemic to tropical forests in Asia. It is categorized as Endangered by IUCN and listed as CITES Appendix II species. Although three subspecies (T. p. phayrei, T. p. crepusculus, and T. p. shanicus) have been identified, little is known about the taxonomic status and ecology of Phayres leaf monkey in the region. This study aimed at confirming the taxonomic status of Phayres leaf monkey in Myanmar and also understanding its behaviors and habitat uses in order to provide species conservation and habitat management. This study was the first molecular work using non-invasive samples (hair and feces) and non-destructive sample (bones from dead animal) to investigate the phylogenetic status of Phayres leaf monkey in Myanmar particularly Popa Mountain Park (PMP) and Alaungdaw Kathapa National Park (AKNP). Two DNA markers, nuclear protamine P1 (Prm1) and mitochondrial cytochrome b (Cyt-b) genes were used. The population from PMP is more closely related to the subspecies T. p. shanicus from the southwest China, while that from AKNP cluster together with subspecies T. p. phayrei from the northeast India. Three groups of Phayres leaf monkey (mean 41  0.67, 41  0.58 and 21  0.67 individuals for group-1, group-2, and group-3, respectively) were recorded in PMP. The monkey highly occupied semi-evergreen forest with little or no disturbances (occupancy value:  = 0.7679, SE = 0.182) in PMP. The occurrence of monkey was positively related with the forest stand characteristics (Spearmans rank correlation: tree density (tree/plot): s = 0.305, P = 0.039

basal area (m2/plot): s = 0.469, P < 0.0001

mean tree height (m): s = 0.583, P < 0.0001). The availability of food resources was significantly different between the forest stands occupied by Phayres leaf monkey and those were not used by the monkey. In this study, food plants for the monkey consisted of fourteen different families including Moraceae and Myrtaceae. Moreover, Phayres leaf monkey also eats climbers (Cissus vitiginea, Piper attenuatum and Smilax perfoliata) which have not been recorded elsewhere in its range. Phayres leaf monkeys spent most of their time for feeding (54%) followed by resting (32%), travelling (7%) and other activites (7%). The monkeys travelled randomly on ground and tree strata (Kruskal-Wallis H test: H = 3.527, df = 4, P = 0.474) but they displayed non-randomly for feeding, resting and other behviors (i.e grooming, playing) (Kruskal-Wallis H test: feeding: H = 23.214, df = 4, P < 0.0001

resting: H = 23.291, df = 4, P < 0.0001

others: H = 11.107, df = 4, P = 0.025). Phayres leaf monkey spent slightly more time for resting in winter (31.65%) than that in summer (28.73%) and rainy (27.63%). Two feeding peaks were recognized in the early morning (0600 – 0800 h) and another in the late evening (1600 -1800 h). However, in terms of the pooled data set for all time intervals, there were no significant differences except for other behaviors (i.e. grooming or playing) (Kruskal-Wallis H test: H = 13.28, df = 5, P = 0.021). The study suggests that seasonal and time differences will not affect the behavior of animals if there were enough food resources at their habitats for a year round. Habitat suitability for Phayres leaf monkey in PMP was created using the landscape habitat suitability index (HSI) model. The highly suitable habitat (5.28%) was lying to the northern part of PMP, followed by suitable (12.63%), moderately suitable (23.54%), least suitable (26.31%) and unsuitable (32.24%) habitats. The outputs of habitat suitability map were easily understandable and it can be used for park management plans particularly conserving the suitable habitats for Phayres leaf monkey. In conclusion, taxonomic information provided by this study can be used as basis to conserve genetic resources of threatened species particularly Phayres leaf monkey from PMP as this population revealed genetic characters different from other subspecies of T. phayrei. Moreover, information on the food resources and the suitable habitats of Phayres leaf monkey can be considered for upgrading the park management plan by conserving main food resources and protecting the suitable habitats.