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Summary: Bustards comprise a highly threatened family of birds and, being relatively fast, heavy fliers with very limited frontal visual fields, are particularly susceptible to mortality at powerlines. These infrastructures can also displace them from immediately adjacent habitat and act as barriers, fragmenting their ranges. With geographically ever wider energy transmission and distribution grids, the powerline threat to bustards is constantly growing. Reviewing the published and unpublished literature up to January 2021, we found 2,774 records of bustard collision with powerlines, involving 14 species. Some studies associate powerline collisions with population declines. To avoid mortalities, the most effective solution is to bury the lines; otherwise they should be either routed away from bustard-frequented areas, or made redundant by local energy generation. When possible, new lines should run parallel to existing structures and wires should preferably be as low and thick as possible, with minimal conductor obstruction of vertical airspace, although it should be noted that these measures require additional testing. A review of studies finds limited evidence that 'bird flight diverters' (BFDs; devices fitted to wires to induce evasive action) achieve significant reductions in mortality for some bustard species. Nevertheless, dynamic BFDs are preferable to static ones as they are thought to perform more effectively. Rigorous evaluation of powerline mortalities, and effectiveness of mitigation measures, need systematic carcass surveys and bias corrections. Whenever feasible, assessments of displacement and barrier effects should be undertaken. Following best practice guidelines proposed with this review paper to monitor impacts and mitigation could help build a reliable body of evidence on best ways to prevent bustard mortality at powerlines. Research should focus on validating mitigation measures and quantifying, particularly for threatened bustards, the population effects of powerline grids at the national scale, to account for cumulative impacts on bustards and establish an equitable basis for compensation measures. [ABSTRACT FROM AUTHOR]

The jumping spider species Plexippus minorWesołowska & van Harten, 2010, known from the United Arab Emirates is here reported from India, from the Desert National Park Wildlife Sanctuary in the state of Rajasthan. Detailed redescriptions with high quality illustrations of both Indian and type specimens of P. minor, including 3D models of the type, are presented, and the distribution is updated. This work increases the number of Plexippus species in India to seven. [ABSTRACT FROM AUTHOR]

Pseudomonas aeruginosa is a potent biofilm forming organism causing several diseases on host involving biofilm. Several natural and synthetic molecules have been explored towards inhibiting the biofilm formation of Pseudomonas aeruginosa. In the current report, the role of a natural molecule namely caffeine was examined against the biofilm forming ability of P. aeruginosa. We have observed that caffeine shows substantial antimicrobial activity against P. aeruginosa wherein the minimum inhibitory concentration (MIC) of caffeine was found to be 200 μg/mL. The antibiofilm activity of caffeine was determined by performing a series of experiments using its sub-MIC concentrations (40 and 80 μg/mL). The results revealed that caffeine can significantly inhibit the biofilm development of P. aeruginosa. Caffeine has been found to interfere with the quorum sensing of P. aeruginosa by targeting the swarming motility. Molecular docking analysis further indicated that caffeine can interact with the quorum sensing proteins namely LasR and LasI. Thus, the result indicated that caffeine could inhibit the formation of biofilm by interfering with the quorum sensing of the organism. Apart from biofilm inhibition, caffeine has also been found to reduce the secretion of virulence factors from Pseudomonas aeruginosa. Taken together, the results revealed that in addition to biofilm inhibition, caffeine can also decrease the spreading of virulence factors from Pseudomonas aeruginosa. [ABSTRACT FROM AUTHOR]

Several strategies were undertaken to increase the fertility of landfill soil as rapid urbanization remarkably decreases the agricultural land, posing challenges to the fast-growing human population. Towards this direction, soil microcosms were prepared wherein the addition of nutrient or biofertilizer or the combination of both increased the soil nitrogen and phosphate content considerably. The maximum amount of nitrogen fixation and phosphate solubilization occurred in microcosm treated with biofertilizer and nutrient. To investigate the underlying cause, we observed that separate application of nutrient or biofertilizer or combined application of both increased the abundance of nitrogen-fixing and phosphate-solubilizing bacteria in the microcosms. However, the highest abundance of nitrogen-fixing and phosphate-solubilizing bacteria was spotted in a microcosm challenged with nutrient and biofertilizer together. It was detected that with increasing population of nitrogen-fixing and phosphate-solubilizing bacteria, the soil nitrogen and phosphate level also got enhanced, respectively, thus establishing a strong positive correlation between them. The microcosm treated with biofertilizer and nutrient manifested the highest degree of heterotrophic microbial growth and microbial activity than the microcosms either treated with nutrient or biofertilizer. The microcosm treated with nutrient and biofertilizer was found to exhibit the highest functional diversity compared to others. A surface plot was constructed to demonstrate the association among microbial activity, functional diversity, and the availability of soil nitrogen and phosphate content of soil. The result indicates that the combined application of nutrient and biofertilizer increases the microbial activity leading to the formation of a heterogeneous ecosystem that enhances the nitrogen and phosphate content of landfill soil considerably. [ABSTRACT FROM AUTHOR]

Subsistence fishery for cephalopods contributes significantly to the local economy of several Asian, African and island states. In addition to being unregulated and undocumented, recent studies indicate that low-scale fisheries can have detrimental effects on marine ecosystems. In the Lakshadweep islands, men, women and children have been involved in spear fishing for octopus for a long time, but there is a paucity of information on the biology and fishery of the octopus species in Indian waters. In this study, we estimated the population abundance, morphometry and sex ratio of Octopus cyanea. Moreover, we examined whether the current octopus spear fishing activity displayed size or sex selectivity, given that larger individuals are easier to spot and brooding females spend more time in crevices. O. cyanea surveys were conducted by snorkeling in the lagoons of Kavaratti and Agatti islands between November 2008 and April 2012. The estimated mean density of O. cyanea was 3 and 2.5 individuals per hectare in Agatti and Kavaratti, respectively. Individual mean weight was 923.36 g and 846.26 g in Agatti and Kavaratti and the male:female sex ratio 1.35:1 and 3.8:1, respectively. Comparison between visual counts and fisheries landings indicated that fishing effort was concentrated in areas of high juvenile abundance but without female-bias. Constructing a long-term database of fishery catches will help with stock assessment and understanding the factors that influence octopus populations. Implementation of a lower size limit of 500 g would act as a precautionary measure against catching very small octopuses. [ABSTRACT FROM AUTHOR]

A thorough understanding of mechanisms of prey consumption by carnivores and the constraints on predation help us in evaluating the role of carnivores in an ecosystem. This is crucial in developing appropriate management strategies for their conservation and mitigating human-carnivore conflict. Current models on optimal foraging suggest that mammalian carnivores would profit most from killing the largest prey that they can subdue with minimal risk of injury to themselves., Wild carnivore diets are primarily estimated through analysis of their scats. Using extensive feeding experiments ( n = 68) on a wide size range (4·5-130 kg) of obligate carnivores - lion, leopard, jungle cat and domestic cat, we parameterize biomass models that best relate consumption to scat production. We evaluate additional constraints of gut fill, prey digestibility and carcass utilization on carnivory that were hereto not considered in optimal foraging studies., Our results show that patterns of consumption to scat production against prey size are similar and asymptotic, contrary to established linear models, across these carnivores after accounting for the effect of carnivore size. This asymptotic, allometric relationship allowed us to develop a generalized model: biomass consumed per collectable scat/predator weight = 0·033-0·025exp−4·284(prey weight/predator weight), which is applicable to all obligate carnivores to compute prey biomass consumed from scats. Our results also depict a relationship for prey digestibility which saturates at about 90% for prey larger than predator size. Carcass utilization declines exponentially with prey size. These mechanisms result in digestible biomass saturating at prey weights approximately equal to predator weight., Published literature on consumption by tropical carnivores that has relied on linear biomass models is substantially biased. We demonstrate the nature of these biases by correcting diets of tiger, lion and leopard in recent publications. Our analysis suggests that consumption of medium-sized prey was significantly underestimated, while large prey consumption was grossly overestimated in large carnivore diets to date. We highlight that additional constraints of prey digestibility and utilization combined with escalating handling time and risks of killing large prey make prey larger than the predator size unprofitable for obligate carnivores. [ABSTRACT FROM AUTHOR]

The great Indian bustard ( Ardeotis nigriceps) is an endemic endangered bird of the Indian subcontinent with a declining population, as a result of hunting and continuing habitat loss. In this first genetic study of this little-known species, we investigate the diversity of the mitochondrial DNA (hypervariable control region II and cytochrome b gene) among samples ( n = 63) from five states within the current distribution range of great Indian bustards in India. We find just three haplotypes defined by three variable sites, a comparatively low genetic diversity of π = 0.0021 ± 0.0012 for cytochrome b, 0.0008 ± 0.0007 for the control region (CR), and 0.0017 ± 0.0069 for combined regions and no phylogeographic structure between populations. We provide evidence for a bottleneck event, estimate an effective population size ( Ne) that is roughly concordant with recent population size estimates based on field surveys (~200 to 400), but extremely low for a widely distributed species. We also discuss the conservation implications. Based on our findings, we strongly recommend upgrading the IUCN threat status from Endangered to Critically Endangered. [ABSTRACT FROM AUTHOR]

The endemic great Indian bustard (GIB) is evolutionarily trapped between open nesting and k-selection that endangers its persistence under prevailing levels of habitat loss and hunting. A global population of about 300 birds is further fragmented into eight populations in the states of Rajasthan (shared with Pakistan), Maharashtra, Andhra Pradesh, Gujarat, Karnataka, and Madhya Pradesh in India. The largest population of 100-125 birds exists in Jaisalmer, Barmer, and Bikaner districts of Rajasthan. Remaining populations number less than 35 birds each. Prevalent GIB conservation strategies use legislation to (a) secure traditional breeding areas by declaring small Protected Areas (PA) or (b) protect vast areas with varied human land uses. The vagrant nature of GIB reduces the benevolent effect of small PAs, while large reserves alienate people by curbing legitimate subsistence rights through strict legislation. These factors along with ill-informed habitat management challenge the current PA approach, even causing local extinctions. Population viability analysis shows that GIB populations of ≤35 birds can persist only under unrealistic conditions of first year mortality ≤40%, and no human caused mortality of adult birds. Even the largest population (≥100 birds) is sensitive to additional loss of adult birds to human causes. With current levels of hunting in Pakistan, extinction is a real threat. A landscape conservation strategy using conservation/community reserve concept that includes controlled traditional land uses with GIB-friendly infrastructural development is needed. The declining rate of GIB populations calls for immediate commencement of ex situ conservation breeding programs. [ABSTRACT FROM AUTHOR]

Compounding effects of slow life-history traits and adult-specific overharvesting have caused a range-wide decline of several giant clam populations. Erratic changes in these populations reported at isolated reefs, are attributable to stochastic fluctuations in recruitment and survival rates. These population rate parameters may be adversely influenced by the considerable and increasing human-reef economic interactions in tropical waters. The unsubstantiated knowledge on such influences hinders conservation management of species-habitat linkages particularly for species like the small giant clam (Tridacna maxima). Our study reports small giant clam survival rate, its ecological determinants and stochastic fluctuations from shallow lagoon waters of Lakshadweep Archipelago; a natural habitat not subjected to commercial giant clam harvesting. Survival rate was estimated by monitoring the status of identified individuals in belt-transects through successive years 2005-2009. The role of different factors in explaining the variation in survival rates was investigated at relevant scales: anthropogenic pressure at the population level in the reef, clam density at sub-population level in the belt-transects, and variables related to clams at the individual level. Effects were quantified through univariate regression techniques and Kaplan-Meier estimator coupled with generalized linear (logit link) models. Small giant clam survival rate in the reef decreased and its spatio-temporal fluctuations increased along the increasing gradient of human populations. Survival was density-independent. Size/age specific survival followed Siler distribution characterized by very low early-age survival, increased adult-age survival, and low older-age survival. Anchorage in coral substrate exerted a curvilinear effect, where survival of moderately anchored clams > loosely anchored clams >> deeply embedded clams. Our study recommends regular population monitoring in densely inhabited islands to detect incipient changes, which can subsequently be confronted by scientific lagoon bed management. [ABSTRACT FROM AUTHOR]

Giant clams are endangered in many parts of their Indo-Pacific range owing to adult specific overharvesting that threatens recruitment, a demographic parameter exhibiting high sensitivity to environmental disturbances and adult densities among tridacnids. Lakshadweep reefs are not subjected to commercial giant clam fishery, and population assessment has not been carried out in these waters so far. We monitored the small giant clam Tridacna maxima populations in confined waters of 12 reefs in Lakshadweep Archipelago during 2005-2007 using a systematic line transect based distance sampling framework. Overall T. maxima density in the Archipelago was estimated at 141.2/ha (95% CL 118.2-168.7) in 2005 and 122.7/ha (103.60-145.37) in 2006. Populations showed wide variation in densities and relative proportions of different age-classes between reefs. While Agatti, Bitra and Chetlat lagoons harboured high clam densities, Amini harboured the most impoverished population. Data simulation showed that total clam count along transects of 100 m length x 2-5 m strip width, in a minimum of 140 replicates, stratified by area among lagoons, would provide a viable monitoring index for rapid assessments of T. maxima in Lakshadweep. Compared to unbiased absolute abundance estimates, this monitoring index could be achieved more easily, without much compromise on accuracy and precision, necessary for meaningful spatio-temporal comparisons. [ABSTRACT FROM AUTHOR]