Are Northeastern Forests of Bangladesh Empty? Insights from Camera-Trapping into Spatiotemporal Activity Pattern of Mammals in a Semi-Evergreen National Park

Abstract. Bangladesh holds 191 km2 semi-evergreen northeastern (NE) forests where systematic camera-trapping has never been carried out. An effort of 587 trap nights in Satchari National Park, a NE forest, revealed ten carnivores, two ungulates, two primates, two rodents, and one treeshrew (12 threatened in Bangladesh; of which three globally threatened; dhole and northern treeshrew were new discoveries). Pairwise circadian homogeneity, coefficient of temporal overlap ( ), and spatial cooccurrence pattern were measured. High values ( > 0.75) were noted in 36 pairwise comparisons, and positive spatial association (Pgt < 0.05) in five. Anthropogenic activities overlapped with diurnal species (0.65 ≤ 1 ≤ 0.88) but stood dissimilar (P < 0.05 in the Mardia-Watson-Wheeler test) except for yellow-throated marten–livestock movement (1 = 0.70). Although species-specific dietary or temporal preference explains the observed associations, low detection of the jungle cat (2) compared to the leopard cat (56), absence of the fishing cat, homogenous activity (P > 0.05) in yellow-throated marten–crab-eating mongoose (1 = 0.83) and rhesus macaque–pig-tailed macaque (4 = 0.93) pairs need further research. These insights are remarkable as NE forests, the western cusp of the Indo-Burma biodiversity hotspot, are contrarily deemed ‘empty’, receiving least scientific investments.