Habitat monitoring and conservation prioritization of Western Hoolock Gibbon in upper Brahmaputra Valley, Assam, India.

The present study aimed at predicting the potential habitat of Western Hoolock Gibbon (Hoolock hoolock) in the upper Brahmaputra River Valley, Assam, India, and identifying priority conservation areas for the species, taking canopy cover into account. We used the maximum entropy algorithm for the prediction of the potential habitat of the gibbon using its current distribution with 19 environmental parameters as primary predictors. Spatio-temporal analyses of the habitat were carried out using satellite-based remote sensing and GIS techniques for two decades (1998-2018) along with Terra Modis Vegetation Continuous Field product to examine land use land cover (LULC), habitat fragmentation, Normalized Difference Vegetation Index (NDVI) and tree cover percentage of the study area. To identify the conservation priority area, we applied a cost-effective decision-making analysis using systematic conservation prioritization in R programming. The model predicted an area of 6025 km2 under high potential habitat, a major part of which was found to overlap with dense forest (80%), followed by moderately open forest (74%) and open forest (66%). The LULC change matrix showed a reduction of forest area in the predicted high potential habitat during the study period, while agricultural class showed an increasing trend. The fragmentation analysis indicated that the number of patches and patch density increased from 2008 to 2018 in the 'very dense' and 'dense' canopy regions of the gibbon habitat. Based on the conservation priority analysis, a 640 km2 area has been proposed to conserve a minimum of 10% of gibbon habitat. The current analysis revealed that in the upper Brahmaputra Valley most areas under dense forest and dense canopy have remained intact over the last two decades, at least within the high potential habitat zone of gibbons independent of the degree of area change in forest, agriculture and plantation.

A comparative assessment of external morphological traits between Macaca munzala, Tawang and Macaca assamensis, Goalpara population in Northeast India.

The present study aimed to conduct a comparative assessment of the external morphology, relative tail length and colour variation (RGB additive colour model) of Macaca munzala, Tawang and Macaca assamensis, Goalpara (southern Brahmaputra population), using a non-invasive photogrammetry method. The study revealed that the relative tail length of M. munzala (0.43 ± 0.03) is similar to that of M. assamensis assamensis, a subspecies of M. assamensis. On the other hand, the relative tail length of M. assamensis, Goalpara (0.61 ± 0.04) is similar to M. assamensis pelops, the other subspecies of M. assamensis. A total of 12 external morphological traits were observed and similarities found between the two studied populations. The study also found that the species-specific traits of M. munzala such as "dark patch of the crown whorl", "dark patch of hair at the temporal side", "spectacle appearance around eyes" and "whip-like tail appearance" in the infant and "stocky tail" are present in M. assamensis, Goalpara as well. Likewise, the "chin and cheek whiskers" are found in adult female individuals of both species. The comparative assessment of the dorsal coat colour (RGB value) revealed a darker brown dorsal coat in M. munzala (R 123.14 ± 11.62; G 107.71 ± 10.37, B 89.43 ± 9.21) than in M. assamensis, Goalpara (R 136 ± 23.57, G 112 ± 15.63, B 97.83 ± 13.04). The comparative assessment of facial skin colour among the adult individuals showed that the male M. munzala has darker brown facial skin than that of M. assamensis, whereas the female M. munzala shows darker reddish facial skin compared to M. assamensis, Goalpara. The species-specific traits of M. leucogenys were also compared, and the traits "chin and cheek whiskers", "darker dorsal coat" and "round penile" appearance have a striking resemblance to those of the M. munzala population of Tawang. Thus, the external morphological traits that are being used to distinguish these macaque species are highly variable even within the same species, and there is an urgent need to identify more precise species-specific morphological traits.

Monitoring land use land cover changes in the Eastern Himalayan landscape of Nagaland, Northeast India.

The escalating demand for anthropic needs and urban development has highlighted the importance of monitoring and change detection of land use land cover (LULC). With an increase in agricultural expansion and infrastructural development, every land surface on earth calls for a long-term investigation of land modification patterns and their underlying contributory factors. The present investigation monitors the LULC changes and assesses the process controls in Kohima and Dimapur districts of Nagaland, India. Currently, these two districts encompassing the main urban cities of the hilly state are experiencing rapid urbanization and unplanned developmental activities. Alike any other LULC changes observed in unplanned and developing cities, these districts are likely to face environmental degradation, and particularly, the occurrence of frequent landslides and flash floods. The study has three objectives-(i) LULC mapping of Kohima and Dimapur districts for three periods (1998, 2008, and 2018), (ii) comparative analysis of LULC change patterns in the two districts during the three epochs (1998-2008, 2008-2018, and 1998-2018), and (iii) assessment of the contributory factors. For the study, remotely sensed LANDSAT images (TM and OLI) in Geographical Information System (GIS) platform were utilized along with field surveys. Supervised classification technique was employed and four major LULC classes were identified using Landsat level-1 classification system. The overall accuracy of the classification varied between 91 and 98%. Results showed that Built Up areas have increased significantly in both the districts at the rate of 322.6 ha/year in Kohima and 301.9 ha/year in Dimapur during 1998-2018. On the other hand, Agricultural Land and Forest Land declined in both districts. Changes in LULC were mainly due to marginalization of shifting cultivation, deforestation, infrastructural development, urban migration, and flourishing of aquaculture farming. This study furnishes baseline information on LULC in the data-scarce region of Northeast India and is an insinuation to the policy-makers to ensure sustainable land use planning in the face of rapid urbanization.