No abstract

Information on the presence and distribution of species is crucial for conservation planning and management within a region. Documentation of species assemblages in Manas National Park (MNP) in the aftermath of conflict is critical for informed conservation interventions. For nearly two decades , conservation efforts in MNP were compromised by ethno−political conflict. We conducted camera trapping surveys of terrestrial mammals across three administrative forest ranges (Panbari, Bansbari and Bhuyanpara) of MNP in 2017. A systematic survey with 118 trap locations accumulated data over 6,173 trap-days. We obtained 21,926 photographs of mammals belonging to 13 families and 25 species, of which 13 are threatened. We calculated photographic capture rate index (PCRI) using independent events. Trap specific PCRI's were used to map the spatial variation in capture rates. We observed variation in capture rate between Bansbari-Bhuyanpara where conflict ended in 2003 and has remained peaceful, and Panbari, a forest range where conflict ended later in 2016. Our results further indicate lower capture rates of mammalian prey species and small felids, but higher capture rates of four large carnivores in Panbari as opposed to Bansbari-Bhuyanpara. These results highlighted the fact that despite a history of ethno-political conflict in the region, although almost all mammalian species expected to occur in the park were detected and confirmed, present evidence indicated ethno-political conflict influences the distribution of several key species. In depth studies assessing mammalian prey densities, distribution and density are required to further understand the effects of conflict.

Inferring the mechanisms that facilitate sympatry amongst large mammalian carnivores in anthropogenically altered habitats is critical if conservation initiatives aimed to recover populations are to be effective. In this study, we assessed the utilization of space, time and prey resources by tigers Panthera tigris, leopards P. pardus and dholes Cuon alpinus  in Manas National Park (MNP), India – a site where prey densities are not limiting, yet anthropogenic influences alter the spatial and temporal behaviour of prey. We use photographic capture data and predator scats collected over three sampling years (2014–15, 2015–16 and 2016–17) to assess patterns of (a) spatial use using a multispecies species occupancy framework, (b) time–activity patterns and overlap between predators and prey using non‐parametric circular kernel‐density functions, (c) fine‐scale spatio‐temporal behaviour by comparing time‐to‐encounters of subsequent events and (d) predator diets by analysing prey remains in predator scats. Our results highlight that the predators segregate through fine‐scale spatio‐temporal avoidance rather than displaying population‐level changes in space‐use, activity patterns or food habits. Overlap in space‐use between tigers and leopards was high and time–activity patterns of the predators closely matched those of prey, suggesting that predators likely maximize resource acquisition in this prey‐rich environment. Ungulate prey dominated the diet of predators, resulting in the high dietary overlap. From our results, we infer patterns of sympatry among large carnivores in the face of anthropogenic influences and highlight the need to understand interspecific interactions within a community before initiating conservation actions aimed at recovering these endangered species.

Melanism is a form of pigmentation polymorphism where individuals have darker colouration than what is considered the ‘wild’ phenotype. In the case of leopards, Panthera pardus, melanism occurs at higher frequencies amongst populations in tropical and subtropical moist forests of south and southeast Asia, presenting a unique challenge in estimating and monitoring these populations. Unlike the wild phenotype that is readily recognizable by its rosette patterns, melanism results in individuals being unidentifiable or ‘unmarked’ through photographic captures obtained using white flash cameras. Spatial mark‐resight (SMR) models that require only a subset of the population to be ‘marked’ offer the opportunity to estimate population density. In this study, we present an application of SMR models to estimate leopard densities using camera trap survey data from three sampling years at Manas National Park (MNP), India. By using an SMR model that allowed us to include captures of unidentified sightings of marked individuals, we were also able to incorporate captures where identity was either not confirmed or only known from a single flank. Following 18 674 trap‐days of sampling across three years, we obtained 728 leopard photo‐captures, of which 22.6% (165) were melanistic. We estimated leopard densities of 4.33, 2.61 and 3.37 individuals/100 km2 across the 3 years. To our best knowledge, these represent the first known estimates of leopard densities from populations comprising both melanistic and wild phenotypes. Finally, we highlight that SMR models present an opportunity to revisit past camera trap survey data for leopards and other species such as Jaguars, P. onca, that exhibit phenotypic polymorphism towards generating valuable information on populations.

Melanism is a form of pigmentation polymorphism where individuals have darker coloration than what is considered the “wild” phenotype. In the case of leopards, Panthera pardus, melanism occurs at higher frequencies amongst populations in tropical and subtropical moist forests of south and southeast Asia, presenting a unique challenge in estimating and monitoring these populations. Unlike the wild phenotype that are readily recognizable by their rosette patterns, melanism results in individuals being unidentifiable or ‘unmarked’ through photographic captures obtained using white flash cameras. Spatial mark-resight (SMR) models that require only a subset of the population to be ‘marked’ offer the opportunity to estimate population density. In this study, we present an application of SMR models to estimate leopard densities using camera trap survey data from three sampling sessions at Manas National Park (MNP), India. By using an SMR model that allowed us to include captures of unidentified sightings of marked individuals, we were also able to incorporate captures where identity was either not confirmed or only known from a single flank. Following 18,674 trap-days of sampling across three sessions, we obtained 728 leopard photo-captures, of which 22.6% (165) were melanistic. We estimated leopard densities of 4.33, 2.61and 3.37 individuals/100km2 across the three sessions. To our best knowledge, these represent the first known estimates of leopard densities from such populations. Finally, we highlight that SMR models present an opportunity to revisit past camera trap survey data for leopards and other species that exhibit phenotypic polymorphism towards generating valuable information on populations.