RESUMO
Nepal initiated numerous hydropower and irrigation-related infrastructure projects to enhance and promote green energy, water security, and agricultural productivity. However, these projects may pose risks to natural habitats and the well-being of aquatic fauna, leading to significant effects on delicate ecosystems. To understand these potential impacts, it is crucial to gather reliable baseline data on the population status and habitat characteristics of species. This study specifically focuses on Gharials (Gavialis gangeticus), a critically endangered species. We recorded data on pre-determined habitat variables at stations spaced 500 m apart along the two major river streams of Bardia National Park, as well as at locations where Gharials were sighted between February and March 2023. We used binary logistic regression with a logit link function to investigate the habitat characteristics related to the occurrence of Gharials. The presence/absence of Gharials at sampling points served as the dependent variable, while 10 other predetermined variables (ecological variables and disturbance variables) served as independent variables. Our study recorded 23 Gharials, comprising 14 adults, six sub-adults, and three juveniles, with a sex ratio of 55.56 males per 100 females. Most individuals (83%) were found basking. Among the 10 habitat predictors, three variables (mid-river depth, river width, and water temperature) were significantly correlated (p < .05) with the probability of Gharial occurrence. The model shows that Gharial detection probability increases with greater mid-river depth and width and lower water temperature. This study establishes a population baseline for Gharials within the river system before the construction of large infrastructure projects, such as dams and irrigation canals. It also recommends continuous monitoring of Gharial populations after water release and/or diversion to evaluate the impact of large infrastructure projects on the population and their associated habitat characteristics. This will help enable more informed and targeted conservation efforts.
RESUMO
Spiders (order Araneae) have a worldwide distribution. As of June 17, 2022, the World spider catalog, Version 23.0, enlists 50,188 species of spiders from throughout the world. Except for the open sea and air, spiders live in every ecological environment. They prefer densely vegetated environments and are the world's seventh most diverse group of creatures in terms of species diversity. The checklist of spiders of south Asia mentions 222 spider species from Nepal, grouped into 23 families. However, the official database of the Nepalese government only lists 175 species of Nepalese spiders. This checklist is a vital update to the diversity of the spider fauna of Nepal. The goal is to compile a thorough list of all the spiders found in Nepal. We have enlisted 386 different spider species from Nepal, belonging to 135 different genera and 34 different families, after reviewing previous scientific publications, computer databases of the Nepalese government, and the World spider catalog, Version 23.0. It adds a total of 211 new spiders to Nepal's biodiversity database. Linyphiidae and Salticidae spiders dominate accounting for 27.46 percent and 17.36 percent of total species, respectively, on the checklist. Corrections to previous misidentifications are also included in this checklist, as well as taxonomy revisions. Synonymous species are sorted out to avoid recurrence. The trends in Nepalese spider discovery and dispersion have also been studied.