A geographical assessment of Chariganga and Arpara Beel (wetlands) of Nadia, West Bengal as a habitat of wetland birds

The present study attempts to assess the impact of human intervention on the population, distribution, and habitat perspectives of the water birds found in and around Chariganga and Arpara ‘Beel’ wetlands, leftover channels of the River Bhagirathi. The point count method was adopted during field surveys conducted from April 2019 to March 2020. These wetlands are the natural habitats for 37 species of wetland birds belonging to 18 families and 11 orders, of which 26 species are residents, three are summer migrants, and eight are winter immigrants. The wetlands also harbour 10 bird species whose population is globally declining over the last few decades. Relative Diversity index unveils that among waterfowls Ardeidae is the dominant family. Species richness reaches its peak in winter, and is least during the monsoon. Empirical observation documented one Vulnerable (Greater Adjutant) and one Near Threatened (Black-Headed Ibis) species residing on the banks and adjoining paddy fields. Indiscriminate extraction of wetland products by local people, along with agricultural expansion towards the waterfront of the wetlands, has deteriorated the health of those wetlands and threatened the existence of waterbirds, especially shorebirds. Populations of 22 species living in water edge areas has changed conspicuously owing to cultural and economic activities of neighboring human groups. We suggest improving the ecological balance of the wetlands and restraining further degradation through proper management to preserve avian diversity.

Seabird Migration Strategies: Flight Budgets, Diel Activity Patterns, and Lunar Influence

Every year, billions of birds undertake extensive migrations between breeding and non-breeding areas, facing challenges that require behavioural adjustments, particularly to flight timing and duration. Such adjustments in daily activity patterns and the influence of extrinsic factors (e.g., environmental conditions, moonlight) have received much more research attention in terrestrial than marine migrants. Taking advantage of the widespread deployment in recent decades of combined light-level geolocator-immersion loggers, we investigated diel organisation and influence of the moon on flight activities during the non-breeding season of 21 migrant seabird species from a wide taxonomic range (6 families, 3 orders). Migrant seabirds regularly stopped (to either feed or rest) during migration, unlike some terrestrial and wetland birds which fly non-stop. We found an overall increase for most seabird species in time in flight and, for several species, also in flight bout duration, during migration compared to when resident at the non-breeding grounds. Additionally, several nocturnal species spent more of the day in flight during migration than at non-breeding areas, and vice versa for diurnal species. Nocturnal time in flight tended to increase during full moon, both during migration and at the non-breeding grounds, depending on species. Our study provides an extensive overview of activity patterns of migrant seabirds, paving the way for further research on the underlying mechanisms and drivers.

Birds of Barandabhar Corridor Forest, Chitwan, Nepal

Long term monitoring of bird species was conducted in Barandabhar Corridor Forest, one of the important bird areas of Nepal (IBA). Bird species were identified by the point count method in transect surveys in two-time frames from 2002–2012 and 2015–2016 to obtain the bird species list. We compared our bird list with previously published (after 2000) checklists and compiled the updated checklist of birds of Barandabhar Corridor Forest. We documented 372 bird species belonging to 80 families in Barandabhar, including five Critically Endangered, three Endangered, eight Vulnerable, and 15 Near Threatened species. The Accipitridae family included the highest number of species (n= 32), followed by Muscicapidae (n= 30) and Anatidae (n= 18). Approximately, half of the total confirmed bird species were insectivorous. The list included 63% resident, 27% winter migratory, 7.5% summer migratory, and 2.9% passage migrant species. According to the habitat type, there were 181 species of forest, 74 species of wetland, 24 species of grassland, 70 species of open field, and 23 species of partially wetland birds. This updated checklist of bird species will serve as a reference guide for bird watchers, biodiversity researchers, and support managers for conservation effort; and can be used to track any changes in the composition of bird species in the future.