A baseline study on diversity of birds in Sani Bheri River Valley, Nepal

Rivers and lakes are important habitats for both resident and migratory wetland-dependent birds. This paper presents the study of birds’ seasonal diversity in Sani Bheri River Valley, outside the protected areas of Nepal. The study was carried out from 8-17 March 2019 (Spring) and 12-21 October (Autumn) 2019 covering a 52 km river stretch from Naighat (upstream area where Pelma River and Uttarganga River mix and flow as Sani Bheri river) to Remnaghat (downstream towards the confluence with Thuli Bheri) using the Mackinnon Listing method. The present study recorded 851 occurrences belonging to 11 Orders, 33 Families, and 71 bird species. Order Passeriformes (52 species) and family Muscicapidae (13 species) were dominant. Plumbeous Water-redstart (Phoenicurus fuliginosus) had the highest relative abundance (7.64%). Shannon-Weiner diversity index (H’= 3.61) and Evenness index (e= 0.85) indicate the diverse assemblage of avian fauna in the study area. This study showed that Sani Bheri River Valley provides the habitat for one globally threatened, four nationally threatened, and eight species listed in Appendix-II of CITES. The results provide the baseline information on avian species, which can provide a good database and can be incorporated in conservation implications.

Zooplankton diversity monitoring strategy for the urban coastal region using metabarcoding analysis

Marine ecosystems in urban coastal areas are exposed to many risks due to human activity. Thus, long-term and continuous monitoring of zooplankton diversity is necessary. High-throughput DNA metabarcoding has gained recognition as an efficient and highly sensitive approach to accurately describing the species diversity of marine zooplankton assemblages. In this study, we collected 30 zooplankton samples at about 2-week intervals for 1 year. Zooplankton diversity showing a typical four season pattern. Of the “total” and “common” zooplankton, we assigned 267 and 64 taxa. The cluster structure and seasonal diversity pattern were rough when only the “common” zooplankton was used. Our study examined how to maximize the benefits of metabarcoding for monitoring zooplankton diversity in urban coastal areas. The results suggest that to take full advantage of metabarcoding when monitoring a zooplankton community, it is necessary to carefully investigate potential ecosystem threats (non-indigenous species) through sufficient curation rather than disregarding low-abundance operational taxonomic units.

Diversity of Soil Dwelling Collembola in a Forest, Vegetable and Tea Ecosystems of Assam, India

Land use change has a great impact in determining the diversity patterns of soil fauna. Adoption of any land use pattern significantly affects the soil structure and its physico-chemical characteristics, which often leads to the loss of biodiversity. Considering the collembolans as the key organism in the indicator shopping basket of soil environment, the response of Collembola communities under three different land uses represented by forest, vegetable and tea ecosystems was studied. Collembolans were sampled at monthly intervals using Tullgren funnel and identified by standard taxonomic keys. Diversity analysis and soil chemo-edaphic factors were studied to establish the impact of different land uses on Collembola communities. Five genera of Collembola viz., Cyphoderus, Entomobrya, Isotoma, Folsomia and Hypogastrura were recorded from the forest ecosystem whereas Folsomia was completely absent in vegetable ecosystem and the tea ecosystem soil was devoid of both Folsomia and Hypogastrura. Seasonal diversity and density of Collembola were recorded to be higher in the forest ecosystem indicating the presence of relatively stable habitats as compared to vegetable and tea ecosystems showing relatively disturbed habitats. Correlation studies between different chemo-edaphic factors and collembolan population revealed that the moisture and organic carbon content of soil had significant positive correlation during all the four seasons in all the ecosystems studied. Higher adoption of mechanical and chemo-centric agriculture depletes the available resources of the soil and makes it less habitable and conducive for the growth and sustenance of collembolans in vegetable and tea ecosystem as compared to forest. Appropriate landscape planning, land management strategies and developing proper methods of land use practices may pave the way for the improvement of collembolan diversity at landscape level.

Observation and Seasonal Variation of Lady Bird Beetle (Coleoptera: Coccinellidae)

The Coccinellids, which are commonly called as lady bird beetles belong to the family Coccinellidae of the order Coleoptera. The year was divided into three season viz., summer, monsoon, winter and the diversity was calculated for each season in all the study sites. The highest seasonal diversity was observed during winter season in all the study sites followed by monsoon and summer season.

Impact of orbitally-driven seasonal insolation changes on Afro-Asian summer monsoons through the Holocene

Understanding what drives a shift of the Afro–Asian summer monsoons from the continents to oceanic regions provides valuable insight into climate dynamics, changes, and modeling. Here we use data–model synthesis to focus on the differential seasonal responses of solar insolation and monsoons to orbital changes in the Holocene. We observe coordinated and stepwise seasonal evolution of summer monsoons across the mid-Holocene, suggesting the strengthening of the midlatitude jet stream as a bridge in the upper troposphere. Prior to the mid-Holocene, insolation had decreased considerably in early summer; the continental monsoons migrated southeastward, which corresponded to a more pronounced rainy season in coastal East Asia. In late summer, insolation did not decrease until the mid-Holocene. The continued weakening of the continental monsoons, combined with weakened insolation, rapidly enhanced the intrinsic dynamics over East Asia–Western North Pacific and accelerated a large-scale migration of the monsoon, suggesting orbital control of seasonal diversity.

Butterflies (Lepidoptera: Rhopalocera) in and around the Unakoti Archaeological Site with 59 new additions to the Butterfly Fauna of Tripura, North-eastern India

The authors have surveyed different habitats in and around the Unakoti Archaeological Site and documented a total of 216 species classified under 6 families, 23 subfamilies and 126 genera of the order Lepidoptera. The study was conducted from 2016 to 2020, covering different seasons namely pre-monsoon (Jan-Apr), monsoon (May-Aug) and post-monsoon (Sep-Dec) respectively. The study reports 2 species under schedule I, 25 species under schedule II, and 5 species under schedule IV of the Indian Wildlife (Protection) Act 1972. This study also documented seasonal diversity and habitat-wise occurrence of butterflies in and around the Unakoti Archaeological Site. During the study, 59 butterfly species were recorded as new additions to the butterfly fauna of Tripura. High-quality photographs of all the butterfly species documented during the study have been included in this paper.