生物多様性と絶滅危惧種のジャーナル

A non-invasive study on Dendrocygna viduata was carried out at a selected water body in Osogbo, Osun State, Nigeria to investigate daily, monthly and seasonal patterns in key diurnal activities frequencies to quantify diurnal activity budgets, visibility, and habitat preference. Observations of species activities were evaluated, during morning and afternoon, and twenty six (26) species of Dendrocygna viduata was recorded. Focal animal sampling method was used to select one individual at a time for observation and collection of activity data. Overlapping in collection of data was avoided carefully. Eight key diurnal activities of White-faced Whistling Duck were selected for the study. Normality test for all response variables was conducted using Shapiro-Wilk test for normality, and results was considered significant at 5% level. There was no significant difference in the mean frequency between the different activities, such as flying, resting, bathing and preening. There was a significant difference between the species activities and season and month. During the wet season, the highest mean frequency of activities was observed in April, while in the dry season the highest mean frequency of activities was observed in December. Although, the mean frequency of activities was slightly higher in the afternoon than morning, but it was not significant and does not determine the frequency of activities employed by the White-faced whistling duck. More research is needed to assess this species in early morning or late evening to achieve greatest accuracy and time-efficiency, creating desirable habitat in the vicinity by modifying the dam to encourage aquatic plant development.

River Chenab is one of the highly hydrologically managed rivers in South Asia and facing several environmental issues related to human population growth, industrialization, agricultural advancements and rapid urbanization. These issues are the major threat to the fish diversity of the River Chenab. In this regard, the present study was designed to elucidate the fish diversity, distribution patterns, conservation issues at five artificial water reservoirs (barrages) during the pre-monsoon and post-monsoon season in river Chenab, Pakistan. A total of 5715 individuals was sampled belonging to 16 families. The Cyprinidae (56.9%) was most dominant family followed by Bagridae (7.34%), Cichlidae (5.25%), Schilbeidae (4.55%), Siluridae (3.33%), Ambassidae (3.15%), Clupeidae (3.09%). In Cyprinidae family, Salmophasia bacaila was the most abundant species with relative abundance (10.70%) followed by Osteobrama catio (7.52%), Puntius sophore (5.44%). Ailia coila, Bagarius bagarius, Ompok bimaculatus and Ompok pabda showed low relative abundance. Highest number of fish individuals were reported from the Qadirabad barrage (27%) and lowest from Khanki barrage (14%). Oreochromis niloticus is an exotic species was the fourth most abundant fish species and could be a threat to the local species. Six near threatened species (Ailia coila, Bagarius bagarius, Ompok bimaculatus and Ompok pabda) with restricted distribution, and one endangered species (Tor putritora) was recorded. Generally, small sized fish species were high in number as compared to large sized fishes indicating over fishing of commercial fishes from the barrages. It was observed that there are several other fishing activities reducing the fish number. Illegal and destructive methods of fishing, pollution, flow reduction, water diversion, habitat reduction and human population growth are putting pressure on the fish diversity of River Chenab. Illegal fishing and discharge of effluents without treatment must be addressed to improve the ecological balance of fish assemblage and water quality of the river Chenab

Anthropogenic disturbances are major factors influencing the ecological processes and spatial patterns of a landscape. Most studies which were conducted in the past in the field of landscape ecology were carried out based on the analyses of spatial patterns. However, considering only the spatial patterns is more of descriptive and incomplete. The present study utilized the analyses of both spatial patterns and ecological processes in a landscape scale. The objective of the study was to examine the impacts of logging and other human-induced disturbances on community structure and mechanisms of co-existence among six guild insect species in a landscape scale between 1970 and 2010 in the Munessa Forests. Mathematical model was employed to compute the index values of richness, patchiness, diversity, dominance, and contagion. Moreover, counting was done to determine the number of boxes in each habitat type using box fractal dimension technique. The box fractal dimension was analyzed by regressing the number of boxes counted versus caliber width. Survival and intrinsic rate of population growth for each coexisting species were determined. The results revealed that logging and other human-induced disturbances affected the index values of patchiness, diversity, dominance, and contagion, suggesting that the size of each habitat type and patterns of habitat patches differed between 1970 and 2010. Moreover, the box fractal analysis showed that there was a change in habitat size and patterns of species distribution resulted from the negative impacts of logging and other human-induced disturbances. The stochastic process results suggested that anthropogenic disturbances affected the survival, intrinsic rate of population growth, and co-existence among the six guild insect species through affecting the natural mosaics of habitats and also by aggravating the stochastic causes of species extinction rates. Generally, the combined results obtained from the change in spatial patterns and ecological processes are important to describe and better explain how logging and other human-induced disturbances affected the community structure and mechanisms of coexistence among the six guild insect species in a landscape scale between 1970 and 2010. The findings of this study are crucial to explain and increase our understanding and later predict how the impacts of logging and other human-induced disturbances affect the structure and coexistence of the six guild insect species in a landscape scale. The "Anti-fragmentation Authority" should properly work towards conserving and managing the patches of the four habitat types which are connected one another. Because connectedness increases the dispersal rates of individuals from one habitat patch to another. Edge effect will be also reduced when compacted habitat patches are connected for future conservation goals.

Endangered species are strictly contraband within the world of high fashion couture but not for marine fashionistas. During recent surveys a decorator crab (Hyastenus sp.) was found exclusively covered in a thick coat of the critically endangered marine brown alga, Nereia lophocladia. This marine alga is among only a few to be globally listed as critically endangered and protected by legislation. While decorator crabs are widely known to adorn themselves in algae and other organisms for defense and camouflage, this is the first documented occurrence of critically endangered couture.