Heterogeneous habitat supports cryptic diversity of the terrestrial mammalian community in a protected forest of Bangladesh

Baraiyadhala National Park (BNP) is one of the 53 protected areas in Bangladesh that is attached to the southeastern hilly areas representing mixed-evergreen forest with a couple of waterfalls, deciduous patches, and steep hills. Also, this area is a popular destination for tourists during monsoon season. Here, we studied the relative abundance, diversity, and community composition of terrestrial mammals along with the associated factors implying camera traps in the 48 locations of BNP. Over a span of 2793 days, 2430 independent video clips were obtained between 2022 and 2023 resulting in 27 cryptic species from six orders. Seven of the recorded species were globally threatened (25.93%) including Chinese pangolin (Manis pentadactyla) and pig-tailed macaque (Macaca nemestrina). RAI showed a high index value for Assamese macaque (Macaca assamensis) from primates, northern red muntjac (Muntiacus vaginalis) from cetartiodactyla and small-clawed otter (Aonyx cinereus) from carnivora. In contrast, RAI was relatively small for the Chinese pangolin (Manis pentadactyla) and marbled cat (Pardofelis marmorata). The lack of relationship between elevation and disturbance indicated that species diversity was influenced by the heterogeneity of habitats. Species richness was relatively higher in tropical wet areas (TW) than in forest edge (ED) and steep hills but not significantly varied with semievergreen areas. Species composition was also found to be spatially different; high and low beta diversity was found from TW and ED, respectively. Northern red muntjac was the identical species in this forest that occupied all habitats apart from the ED area. Forest fire and other anthropogenic activities were also evident; however, poachers significantly influenced the species composition rather than villagers, tourists, and domestic animals in BNP. This systematic study provides valuable insights for the future management and conservation of threatened mammals in this national park.