Showing 5 results for Das
Ashish Kumar Jangid, Ravi Kumar Sharma, Dr. Abhijit Das,
Volume 3, Issue 4 (12-2021)
Abstract
We present the first-ever annotated checklist on snakes of the proposed Jawai Community Conservation Reserve of southwestern Rajasthan, India. We opportunistically encountered 26 species of snakes from the study area during the years 2015 to 2017. We have also collated a distribution synopsis for all the observed species with respect to the state of Rajasthan.
Ayan Mondal, Nilanjan Das, Sudipto Mandal,
Volume 4, Issue 1 (3-2022)
Abstract
The domestication of rice (Oryza sativa L.) has a rich history with its diversification from wild progenitors based on genetic differences. For human benefit, natural environments have been agriculturally modified. Concurrently, the biodiversity of natural or wild environments is greatly affected. Here, a comparison has been made between the biodiversity associated with wild-type rice and domesticated rice fields. Species were categorized into broad groups, i.e. Arthropoda (Arth), Other Invertebrate (OInv), Vertebrate (Vert), Algae (Alg), Fungi (Fng), Pteridophyta (Ptrd), and Higher Plant (HPlan). Physico-chemical factors including water depth (WD), water pH (pH), temperature (T), total hardness (TH), dissolved organic carbon (DOC), turbidity (Turb), and dissolved oxygen (DO) were measured directly in the field. Statistical analysis such as Student’s t-test, Kolmogorov-Smirnov test for equal distributions, tests for dominance and multiple indices including Simpson, Shannon, and Evenness were used to assess the biodiversity. Furthermore, Principal Component Analysis (PCA) and Multivariate Analysis of Variance (MANOVA) were used for community comparisons, and SIMPER analysis was used to assess dissimilarity between taxa. The Artificial Neural Network model (ANN) was applied to assess the relative importance of factors governing the system. The present study showed the assemblage of species in the wild along with domestication. The vertebrate species number was well correlated with all the other biotic groups indicating a bottom-up controlling pattern in the rice field ecosystem. The ANN analysis showed that of the environmental factors examined, WD played the most important role followed by pH, T, DOC, and DO as the next most influential factors in distinguishing wild and domesticated rice field ecosystems. SIMPER analysis demonstrated that arthropods were a major contributor to dissimilarity. Collectively our results showed that the domestication of rice led to a decline in biodiversity.
Sagar Adhurya, Debayan Gayen, Suvendu Das, Santanu Ray,
Volume 4, Issue 1 (3-2022)
Abstract
The focus of the present study was (i) to develop a complete checklist, (ii) to find the seasonal variation of waterbird diversity, and (iii) to assess the population trends of different waterbirds at Lake-2 of the Ballavpur Wildlife Sanctuary (BWLS), Birbhum District, West Bengal, India. The study was carried out from January 2018 to November 2019. All waterbirds spanning in the freshwater lake were counted with field binoculars and digital cameras. The bird count data were used to calculate different biodiversity indices (such as Shannon-Weiner diversity index, Simpson’s Diversity Index etc.). Further, we assessed the population trends of different waterbirds with the data available from eBird. A total of 32 waterbird species belonging to 27 genera, 9 families and 8 orders were recorded during the present study. Dendrocygna javanica (Horsfield) was found to be the most dominant species throughout the year. Maximum richness and abundance were recorded during the winter months (December to February), whereas the highest species diversity was recorded during the monsoon months (March to June). The present study further establishes that both the richness and abundance of the waterbirds at BWLS have increased as compared to the past data. However, various species of wading waterbirds that were recorded previously were not observed during the present study. Moreover, the population trend analysis revealed a strong decline in the population of Mareca strepera (Linnaeus) and a moderate increase in the population of Ardeola grayii (Sykes). Thus, the present study concludes that BWLS supports high waterbird diversity irrespective of its small area.
Shipra Khanduri, Vedagiri Thirumurugan, Chandravilasam Sreedharan Nair Vishnu, Chinnasamy Ramesh, Abhijit Das, Gautam Talukdar,
Volume 4, Issue 4 (12-2022)
Abstract
A comprehensive record of reptiles found in the Moyar River Valley Landscape (MRVL) is presented in this manuscript. The observations did not adhere to standardized survey methods, and are based on opportunistic encounters during our vegetation survey in different habitats of the MRVL between December 2017 and December 2019. A total of 135 live individuals and 31 road-killed specimens, representing 37 species of reptiles were recorded of which two species are Vulnerable, 13 are Least Concern and 22 species are Not Evaluated in accordance with the criteria of the IUCN Red List of Threatened Species. The recorded species belonged to six families of lizards (Agamidae, Chamaeleonidae, Gekkonidae, Lacertidae, Scincidae, and Varanidae), six families of snakes (Colubridae, Elapidae, Erycidae, Pythonidae, Typhlopidae, and Viperidae), two families of chelonians (Geoemydidae, and Testudinidae), and one family of Crocodylia (Crocodylidae,). The road-killed specimens were recorded between the year 2018 and 2020 and come under Indian Wildlife Protection Act, 1972. Though the present work did not follow a specific survey method, the contribution provides baseline information on the reptile diversity of the MRVL and presents interesting findings from the Sathyamangalam and Mudumalai Tiger Reserves in north-western Tamil Nadu, India.
Pritom Roy, Antara Das, Md. Asir Uddin, Dr. Jadab Kumar Biswas,
Volume 5, Issue 2 (6-2023)
Abstract
We used linear morphometric measurements to assess secondary sexual dimorphism in the external traits and pelvis of the lesser bandicoot rat, Bandicota bengalensis (Gray). Multivariate analysis of variance revealed significant difference between the sexes in both external (Wilks' lambda = 0.542, F = 3.378, P < 0.05) and pelvis measurements (Wilks' lambda = 0.238, F = 10.05, P < 0.05). Males were larger than females in most of the external traits. In contrast, females were larger in most variables of the pelvis. Separation between the sexes was also demonstrated in the discriminant analysis. Although allometric slopes did not differ between the sexes, means adjusted for allometry were sexually dimorphic in five out of seven variables of the pelvis. In conclusion, our results revealed differential patterns of secondary sexual dimorphism for the external morphology and pelvis in B. bengalensis. These patterns are explained with respect to the accessible evolutionary theories on mammalian sexual dimorphism.
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