Our Nature

Bird diversity along an elevational gradient in Shivapuri Nagarjun National Park, Nepal

2022-12-26T07:05:28+00:00

Shivapuri Nagarjun National Park (SNNP) plays an important role in global biodiversity conservation, but research based on avian diversity along elevation gradients has not been studied yet. Therefore, this study aims to explore avian diversity, its pattern, and environmental variables affecting bird species richness along elevation gradients. The point count method was carried out in the monsoon season (June and July) in 2019. Data for environmental variables including elevation, distance to settlement, distance to nearest water sources, temperature, and precipitation were assessed with respect to the feeding guild. A total of 130 species of bird belonging to 40 families and 12 orders were recorded including the Steppe eagle (endangered species) and Spiny Babbler (only endemic bird of Nepal), which indicate that SNNP supports avian diversity. Diversity indices showed diverse bird community assemblage such as the Shannon-Weiner diversity index (H'=2.65), Simpson diversity index (0.92), and evenness index E=0.94). Our study revealed insectivores were dominating among others and the order Passeriformes had the high species richness. Our observation revealed that the bird species richness was significantly greater at lower elevations than at mid and high elevations, showing a clear monotonic decline in species richness and diversity with increasing elevation. In the case of feeding guild (insectivores, omnivores, frugivores, and carnivores), most of the bird species showed a significant relationship with environmental variables (elevation, distance to settlement, distance to nearest water sources, temperature, and precipitation). It was concluded that not only environmental factors are responsible for affecting avian diversity but elevational gradients consisting of heterogeneous habitats can also play an important role in shaping avian diversity patterns.

Assessment of Aquatic Environmental Parameters of In-Pond Aquaculture System

2022-12-26T07:42:09+00:00

The In-pond raceway aquaculture (IPRA) was developed to increase production that is more controllable and efficient than pond culture system. This study was conducted on commercial scale in IPRA to characterize the water quality and microbial community study within IPRA farms. The IPRA covers an area of 2h of traditional pond with 10 raceways, each of 25m× 5m×2.5m of fish culture units. Where monitoring of water quality parameters and microbial abundancy had been studied between inlet and outlet of the raceways during 108 days of culture period. Average water quality parameters and total soluble solid (TSS) over the course of the study was not found to be significantly difference. Nitrite nitrogen, nitrate nitrogen, total ammonia nitrogen, total phosphorus, chlorophyll-a and chemical oxygen demand were higher in outlet than inlets of IPRA. However, average total nitrogen, soluble reactive phosphorus and total soluble solids concentrations were slightly higher in inlets of IPRA there was also insignificance difference of microbial abundance. Therefore, it can be concluded from this study that fishes in raceways consumed nearly all the feed offered and a negligible amount of feed was wasted. So, leftover feed settlement to the bottom of the pond became a concern of no issue, despite the raceway having intensive fish culture thus bringing non-significant differences in water quality parameters between the inlet and outlet of the IPRA system.

Bee flora of Khumaltar agro-ecosystem, Lalitpur, Nepal

2022-12-26T08:13:14+00:00

This investigation was carried out in Agricultural Research Council (NARC), Khumaltar area, Lalitpur, Nepal to document the seasonal bee flora and diversity patterns. Bees get enough choices to forage in an agro-ecosystem study area. Flowering plants visited by honeybees were observed and documented as per their preferences of foraging, distance away from the bee-hive and seasons. Each plant enlisted as bee-flora if a honeybee visited any flower and rested at least for a while. A total of 168 vascular plant species documented as bee flora in this study. These flora were classified according to season, distance away from the bee-hive, family, genera, species. Simpson and Shannon diversity indices were found higher (0.004 and 3.45) for summer16. Asteraceae family was found to be the most preferred species. Distance of each bee flora was not found significant but season and herbaceous flower were found highly significant contribution. Maximum abundance of Solanum virginianum L. appeared towards the positive end of non-metric multidimensional scaling axis (NMDS2) which was closer to summer16. It signified closer affinity to the beehive and high preferences during summer15. Likewise, the maximum abundance of Vitis vinifera L. towards summer16 and higher positive end of NMDS1 signified favoring more wet loving early blooming species. Relatively higher abundance of species such as Parthenium hysterophorus L., Solanum tuberosum L., Zinnia elegans Jacq., and Solanum melongena L. in the middle of the NMDS axis and spring 16 signified moderate moist loving species. Pattern of bee flora selection, contribution in term of nectar and pollen grain coincided to moisture gradient. This study supports bee farmers for better selection of wild as well as cultivated bee flora for better preference by bees.

Macro-fungi diversity in Thulo Ban Community Forest of Arjam, Myagdi District, Nepal

2022-12-26T08:37:14+00:00

Macro-fungi produce large fructifications that are visible without the help of a microscope. They play an important role in the conservation of forest ecosystems and biodiversity. The current study deals with the diversity of macro-fungi in the subtropical mixed forest of Arjam, Myagdi District. The study was conducted from June to September 2020, at a height of 1250 to 1450 meters above sea level. In three transects, 10 m×10 m quadrat was used and a total of 18 plots were made. A total of 70 macrofungal taxa were collected. Among them, 56 were identified at the species level, and 14 were generic levels belonging to 26 different families and 12 orders. The highest species-containing family was Russulaceae, with 16 species, whereas the densest species was Mycena sp., comprising 11.8 percent and Cantharellus cibarius was the most frequent species, consisting of 44.44 percent.

Fecundity of Glyptothorax telchitta (Hamilton, 1822) from Tamor River, Nepal

2022-12-27T16:00:25+00:00

The present study assesses the fecundity of Glyptothorax telchitta, a hill stream fish from the Tamor River, Nepal. A total of 60 specimens were collected from the Tamor River, with the help of local fishermen between March 2019 and February 2020. The absolute fecundity ranged from 3385 to 14298 eggs with the mean absolute fecundity of 9448.469 ± 607.783. The fish was found to be a medium fecund fish. Relative fecundity ranged from 151 to 529 eggs per gram body weight with mean relative fecundity of 371.38 ± 15.72. Fecundity showed significant positive correlations with ovary weight (r = 0.858) total length (r = 0.844) and total weight (r = 0.825). This indicated that fecundity dependent is mostly on ovary weight. Gonado-somatic index scored the peak values during March (15.15%) and May (15.01%), indicating the fish’s spawning period during the spring season. Egg sizes varied from 0.382 mm to 1.149 mm. The appearance of various sizes of eggs in a single ovary indicated that the fish was a fractional spawner. The ovaries occupied maximum space in the abdomen during the breeding season.