Biodiversity Mapping Survey/Study in Kaziranga National Park (KNP)
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Biodiversity Mapping Survey/Study in Kaziranga National Park (KNP) Mammals Chapter Final Report Prepared by Mr. Sameer B. Bajaru Mammologist 1 Introduction The north east India includes two biodiversity hotspots of the World, Himalayan and Indo- Burma (Mayer et al. 2000; Mittermeier et al. 2004). It is extremely rich in diversity of the mammals; about 269 species are recorded from this region (Choudhury, 2013). Geographic position of the area, situated in overlapping zones of Palaearctic and Oriental region would be the probable reason for its exceptional diversity of the mammals. This region harbours heterogeneous assemblages of mammals form different subregions such as Indian, Himalayan and Indo-chinese. Its mammalian fauna have close affinity with Indo-Chinese followed by Indian and Himalayan subregions (Choudhury, 2013). NE India has played crucial role in shaping mammalian diversity of Indian subregion. Prehistorically it act as corridor for immigration of Indo-Malayan fauna into Indian subregion and also as reserve for tropical species (tropical species gene reservoir) during glacial period (Tamma & Ramakrishnan, 2015). NE India can be physiographically broadly divided into Assam plains and NE hills. Assam plains/Brahmaputra Valley are floodplains, one of the most dynamic ecosystems formed by massive flooding form the Brahmaputra River. This river forms massive and complicated network of some of the Words largest sandy and grassy islands, locally known as Chars/Chaporis. Brahmaputra strongly influenced the vegetation in the Assam plains, mainly dominated by alluvial grasslands, alluvial lowland semi-evergreen forest and mixed deciduous forest (Sharma et al. 2012). The valley includes human settlements, agriculture fields and one of the World's largest tract of the tea gardens. The Brahmaputra valley has been exploited for more than two centaury, mainly for the expansion of agriculture and tea plantation, which was transformed contiguous stretch of forest into isolated fragments those cover < 25% of the valley (Forest Survey of India, 2009). Despite of continuous exploitation, still this regions harbours exceptionally rich biodiversity. For example, seven species of wild cats in single stretch of forests of Jeypore-Dehing (Hance, 2010), seven species of primates (Sharma et al. 2012) in remnant patches of upper Brahmaputra Valley and largest remained populations of mega herbivores such as Great One- horned Rhinoceros, Elephants and Water Buffalos surviving in Kaziranga and Manas National Park. However, most of the protected areas in Brahmaputra valley are small and isolated and they are under tremendous anthropogenic pressure due to reasons mentioned above and also upcoming developmental projects such as hydroelectric, mining, urbanisation, defence and other infrastructural projects. Therefore, there is immediate need to develop protocol for documentation and analysis of the diversity of the region for its conservation and long term assessments. Kaziranga National Park (KNP) is one of the best managed wildlife parks in the World. Though well known for Great One-horned Rhinoceros, Asian Elephants, Water Buffalos, Swamp deer and Tigers, it harbours rich biodiversity - 490 species of birds, 43 species of reptiles and 52 species of mammals (Choudhury, 2013). Though intensive work has been carried on individual species (Patkar, 1980; Kushwaha, 2000; Muley, 2001; Di Fonzo, 2007; 2 Ahmed et al. 2010) there is lack of detailed account of diversity of mammals, especially distribution and richness. For example, status of 21 species of mammals found in surrounding areas of KNP(Choudhury, 2013) is unclear inside the park. Therefore, considering these gaps and need of long term monitoring programme we undertook this study for examining richness, distribution and relative abundance of the mammals in KNP. 3 Objectives 1. Establish baseline data and survey protocols for future biodiversity monitoring. 2. Establish sound, repeatable field methods appropriate for local conditions. 3. Establish rigorous methods for collection and management of data and specimens, including the production of high quality photographic documentation with use of camera traps and cameras. 4. Identify of mammalian assemblages. 5. Bring out management planning by defining habitat preferences and distribution of a range of mammalian assemblages and threats to them. 6. Provide natural history information on a range of mammal species. 7. Documentation of management practices and identification of management zones. 8. Share detailed data and information of KNP and develop stronger coordination among the Forest Department and FREMAA (Flood and River Erosion Management Agency of Assam). Methods The study area was broadly divided into 157 (3 sq. km.) primary grids, of which 12 grids (Forest - 4; grassland - 3; wetland - 3, mixed vegetation - 2) were randomly selected for examining richness, distribution and relative abundance of mammals in KNP (Fig. 1). These grids were further divided into 1 sq. km. secondary grids, while considering the limited accessibility to all the areas of primary grids and high density of the mammals. Generally high animal density areas of species minimizes size of their territory and home range and make ecological sense for selecting smaller grids in high such areas. Though most of secondary grids were selected randomly (n=53), sometimes selection was based on presence of vehicular road, ant poaching camps and risk from elephant, rhino and buffalos in a particular grid. Number of secondary grids chosen for sampling were in proportion to and heterogeneity of habitat types - mixed deciduous forest (n=6), alluvial semi-evergreen forest (n=8), wetland (n=15), wet alluvial grasslands (n=20) and mixed vegetation (n=4). 4 Fig.1. Map of the study area, Kaziranga National Park. The map shows secondary sampling grids and locations. Inset image shows main land cover types in the park overlaid with the sampling grids. 5 Mixed Deciduous Forest - Isolated patches (in grasslands) or linear patches (along alluvial semi- evergreen forest) of mixed deciduous are common in KNP (Fig. 2).They are characterized with Albizia procera, Lagerstroemia speciosa, Lagerstomia parviflora, Bombyx ceiba, Dillenia pentagyna, Dillenia indica and Ziziphus mauritiana (Choudhury, 2013). Large stretches of these forests are found in the northern range of KNP. Alluvial Semi-evergreen Forest - Semi-evergreen forest patches are commonly seen along streams, wetlands and high elevated areas (Fig. 3, hereafter referred as semi-evergreen forest). Some of the species found in these forests are Artocarpus chaplasha, Terminalia myriocarpa, Tetrameles nudiflora, Dillenia scabrella and Ficus spp. Extensive canebrakes are frequently seen in these forests (Choudhury, 2013). In most of the areas these forest are intermixed or flanked with mixed deciduous forest. Wetland - These are waterlogged habitats surrounded with wet alluvial grasslands (Fig. 4). They have great variation in size from ten thousands of hectares to ten hectares; most of them are connected and form a complicated network with rivers in KNP. After monsoon water level of wetlands get reduces and exposed areas are covered with short grass, and they become grazing ground for herbivores. Wetland is key habitat of KNP, most of wildlife, especially large herbivores strongly depends on them for their survival. Wet alluvial grasslands - Approximately half of KNP is covered with wet alluvial grasslands (Fig. 5, hereafter referred as grassland). They are extremely dense and tall, grows up to 3-5m. Commonly observed grasses in this grassland are Saccharum ravennae, Phragmites karka, Arundo donax, Imperata cylindrica and Saccharum spp. (Choudhury, 2013). Mixed vegetation - This is not homogenous (natural) vegetation category, we adapted it for our grid based sampling method. It generally includes sampling grid equally dominated with mixed moist deciduous forest and wet alluvial grassland. They mostly appeared like heavily wooded grasslands. They were seen at fringes of mixed moist deciduous forest tracts or as small isolated patches in grassland. 6 Fig.2 Mixed deciduous forest Fig.3 Wet alluvial semi-evergreen forest 7 Fig.4. Wetland Fig. 5. Wet alluvial grassland We used following methods for sampling richness, distribution and relative abundance of mammals in KNP. All sampling was carried out between 1st November 2015 and 6th February 2016. 8 Vehicular transects: We conducted vehicular transects of 1km length per grid depended on the accessibility. Total 19 transects were sampled in this study. Transects were laid with minimum distance between them 500 - 1000m, while in some cases it was not possible due to limited availability of vehicular road or their situation. We maintained time of 30-45 min/km to keep sampling efforts constant. Number of individuals of mammalian species seen or heard along the transect were counted. Each transect was sampled four times during the study period. Covariates (categorical) such as canopy cover, visibility and vegetation height recorded at every 100m along with day and time of the transect sampled. Total counts: Wetlands available in the grid were sampled, subjected to their accessibility. Ten wetlands were sampled in this study. Total number of individuals of the species observed in wetland was counted. The number of points per wetland varied according to size of the wetland (2-5 points/wetland). Each wetland was sampled four times during the study period. Covariates (categorical) such as type and height