Global population collapse in a superabundant migratory bird and illegal trapping in China

Persecution and overexploitation by humans are major causes of species extinctions. Rare species, often confined to small geographic ranges, are usually at highest risk, whereas extinctions of superabundant species with very large ranges are rare. The Yellow‐breasted Bunting (Emberiza aureola) used to be one of the most abundant songbirds of the Palearctic, with a very large breeding range stretching from Scandinavia to the Russian Far East. Anecdotal information about rapid population declines across the range caused concern about unsustainable trapping along the species’ migration routes. We conducted a literature review and used long‐term monitoring data from across the species’ range to model population trend and geographical patterns of extinction. The population declined by 84.3–94.7% between 1980 and 2013, and the species’ range contracted by 5000 km. Quantitative evidence from police raids suggested rampant illegal trapping of the species along its East Asian flyway in China. A population model simulating an initial harvest level of 2% of the population, and an annual increase of 0.2% during the monitoring period produced a population trajectory that matched the observed decline. We suggest that trapping strongly contributed to the decline because the consumption of Yellow‐breasted Bunting and other songbirds has increased as a result of economic growth and prosperity in East Asia. The magnitude and speed of the decline is unprecedented among birds with a comparable range size, with the exception of the Passenger Pigeon (Ectopistes migratorius), which went extinct in 1914 due to industrial‐scale hunting. Our results demonstrate the urgent need for an improved monitoring of common and widespread species’ populations, and consumption levels throughout East Asia.     

A new ecotoxicological test method for genetically modified plants and other stressors in soil with the black fungus gnat <Emphasis Type="Italic">Bradysia impatiens</Emphasis> (Diptera): current status of test development and dietary effects of azadirachtin on larval development and emergence rate

Background

Few suitable and standardized test methods are currently available to test the effects of genetically modified plants (GMP) on non-target organisms. To fill this gap and improve ecotoxicological testing for GMP, we developed a new soil ecotoxicological test method using sciarid larvae as test organisms.

Results

Bradysia impatiens was identified as a candidate species. Species of the genus Bradysia occur in high numbers in European agroecosystems and B. impatiens can be reared in the laboratory in continuous culture. A functional basic test design was successfully developed. Newly hatched larvae were used as the initial life stage to cover most of the life cycle of the species during the test. Azadirachtin was identified as a suitable reference substance. In several tests, the effects of this substance on development time and emergence rate varied for different temperatures and test substrates. The toxicity was higher at 25 °C compared to 20 °C and in tropical artificial soil compared to coconut fiber substrate.

Conclusions and outlook

Results suggest that the developed test system is suitable to enter a full standardization process, e.g., via the Organisation for Economic Co-operation and Development. Such a standardization would not only assist the risk assessment of GMP, but could include other stressors such as systemic pesticides or veterinary pharmaceuticals reaching the soil, e.g., via spreading manure. The use of sciarid flies as test organisms supports recommendations of EFSA, which stressed the ecological role of flies and encouraged including Diptera into test batteries.

     

Evaluating households’ preferences regarding reducing power outages in rural areas: cases in the Ganges Floodplain in Bangladesh

This paper investigates household preferences regarding an improved supply of electricity in rural Bangladesh, where the expansion of stable electricity is an urgent policy issue. The paper examines household preferences regarding reductions in the frequency and duration of power outages. It also examines prior notification mechanisms that do not necessarily provide an increased supply of electricity but that allow households to prepare for potential power failures. A questionnaire survey designed as a choice experiment was applied to households to elicit preferences. The econometric analysis reveals that villagers prefer a reduction in both the frequency and duration of power outages and a 1-day prior notification of power outages. There are slight disparities in preferences according to the season and the timing of improvements (e.g., summer or winter and all day or peak hours). Thus, the present study may be beneficial for policymakers when considering the provision of electricity supply improvements in rural areas in exchange for slight increases in electricity tariffs.     

Maternal serum alpha-fetoprotein levels and fetal outcome in early second-trimester oligohydramnios

Early second-trimester oligohydramnios was associated with normal maternal serum alpha-fetoprotein (MSAFP) levels in nine out of 26 cases (35 per cent). Congenital malformations of the fetal urinary tract resulting in fetal anuria were present in nine cases; in seven of them, normal MSAFP levels were measured. In contrast, normal MSAFP levels were established in only 2 out of the 17 cases without fetal malformations. These data suggest that fetal urine is the major source of elevated AFP in the maternal compartment in early second-trimester oligohydramnios. This is further supported by the lack of any relationship between concentrations of MSAFP non-reactive with Concanavalin A, originating mainly from the yolk sacderived amniotic fluid AFP pool, and the presence of fetal diuresis. Three out of 26 women had experienced early second-trimester oligohydramnios in a previous pregnancy, suggesting the existence of a recurrence risk for this condition.     

Bio-char Sequestration in Terrestrial Ecosystems – A Review

The application of bio-char (charcoal or biomass-derived black carbon (C)) to soil is proposed as a novel approach to establish a significant, long-term, sink for atmospheric carbon dioxide in terrestrial ecosystems. Apart from positive effects in both reducing emissions and increasing the sequestration of greenhouse gases, the production of bio-char and its application to soil will deliver immediate benefits through improved soil fertility and increased crop production. Conversion of biomass C to bio-char C leads to sequestration of about 50% of the initial C compared to the low amounts retained after burning (3%) and biological decomposition (< 10–20% after 5–10 years), therefore yielding more stable soil C than burning or direct land application of biomass. This efficiency of C conversion of biomass to bio-char is highly dependent on the type of feedstock, but is not significantly affected by the pyrolysis temperature (within 350–500 ^∘C common for pyrolysis). Existing slash-and-burn systems cause significant degradation of soil and release of greenhouse gases and opportunies may exist to enhance this system by conversion to slash-and-char systems. Our global analysis revealed that up to 12% of the total anthropogenic C emissions by land use change (0.21 Pg C) can be off-set annually in soil, if slash-and-burn is replaced by slash-and-char. Agricultural and forestry wastes such as forest residues, mill residues, field crop residues, or urban wastes add a conservatively estimated 0.16 Pg C yr⁻¹. Biofuel production using modern biomass can produce a bio-char by-product through pyrolysis which results in 30.6 kg C sequestration for each GJ of energy produced. Using published projections of the use of renewable fuels in the year 2100, bio-char sequestration could amount to 5.5–9.5 Pg C yr⁻¹ if this demand for energy was met through pyrolysis, which would exceed current emissions from fossil fuels (5.4 Pg C yr⁻¹). Bio-char soil management systems can deliver tradable C emissions reduction, and C sequestered is easily accountable, and verifiable.