Prevalence and drivers of poison use by South African commercial farmers and perceptions of alternative livestock protection measures

The use of poison to eliminate predators is causing African vulture populations to collapse. To understand the prevalence and motivations of this practice we conducted an extensive survey with South African commercial farmers. Using a specialised questioning technique and ad hoc quantitative methods we found that an estimated 22% and 31% of farmers used poison over a 1-year and 5-year period, respectively. Poison use hotspots generally coincided with small stock farming areas. The strongest predictor of poison use was whether farmers believed the practice to be common amongst their peers. Our results suggest that farmers’ attitudes to vultures are primarily positive, and farmers are less likely to use poisons if they frequently encounter vultures on their farm. Overall, our findings provide an understanding on poison use that provides leverage points to change farmers’ behaviour and help avert the African vulture crisis and possible cascading ecosystem impacts.Supplementary informationThe online version of this article (10.1007/s13280-020-01461-2) contains supplementary material, which is available to authorized users.     

Condition-dependent expression of melanin-based coloration in the Eurasian kestrel

Melanin is the most common pigment in animal integuments and is responsible for some of the most striking ornaments. A central tenet of sexual selection theory states that melanin-based traits can signal absolute individual quality in any environment only if their expression is condition-dependent. Significant costs imposed by an ornament would ensure that only the highest quality individuals display the most exaggerated forms of the signal. Firm evidence that melanin-based traits can be condition-dependent is still rare in birds. In an experimental test of this central assumption, we report condition-dependent expression of a melanin-based trait in the Eurasian kestrel (Falco tinnunculus). We manipulated nestling body condition by reducing or increasing the number of nestlings soon after hatching. A few days before fledging, we measured the width of sub-terminal black bands on the tail feathers. Compared to nestlings from enlarged broods, individuals raised in reduced broods were in better condition and thereby developed larger sub-terminal bands. Furthermore, in 2?years, first-born nestlings also developed larger sub-terminal bands than their younger siblings that are in poorer condition. This demonstrates that expression of melanin-based traits can be condition-dependent.     

Prenatal diagnosis of inherited metabolic disorders by quantitation of characteristic metabolites in amniotic fluid: Facts and future

An attempt is made to summarize as completely as possible what is known about the prenatal diagnosis of amino– and organic acidurias by direct measurement of characteristic metabolites in amniotic fluid, and to indicate which disorders can potentially be diagnosed prenatally by direct quantitation of metabolites. Furthermore, the disorders are mentioned in which the prenatal diagnosis was proven to be unsuccessful by this approach. The prenatal diagnoses of a case of propionic acidemia and a case of tyrosinemia type I in the 11th and 12th week of gestational age, respectively, are reported and the prospects of performing amniocentesis in the first trimester for prenatal diagnosis are discussed.     

Transgenic insect-resistant corn affects the fourth trophic level: effects of<Emphasis Type="Italic"> Bacillus thuringiensis</Emphasis>-corn on the facultative hyperparasitoid<Emphasis Type="Italic"> Tetrastichus howardi</Emphasis>

As hyperparasitoids may have a considerable influence on the control of herbivorous arthropods, analyzing the host-mediated impact of Bacillus thuringiensis-plants (Bt-plants) on hyperparasitoids is of interest. Laboratory-scale experiments were conducted in order to assess the potential effect of Bt-corn leaf material on the facultative hyperparasitoid Tetrastichus howardi (Olliff) (Hymenoptera: Eulophidae), mediated through the herbivore Chilo partellus Swinhoe (Lepidoptera: Crambidae) and its primary parasitoid Cotesia flavipes (Cameron) (Hymenoptera: Braconidae). In the Bt-group, significantly less C. flavipes larvae per host spun cocoons and pupated than in the control, and the mean fresh weight of a single C. flavipes cocoon was significantly reduced compared to the control. All C. flavipes cocoons of one host formed cocoon clusters. T. howardi females of the Bt-group parasitized significantly less cocoon clusters than in the control. Moreover, significantly fewer C. flavipes cocoons per cocoon cluster were successfully parasitized as compared to the control. As a consequence, T. howardi females of the control had more offspring than in the Bt-group. Adult female T. howardi offspring of the Bt-group weighed significantly less than in the control, but there was no significant weight difference between males of both groups. Our results suggest that transgenic insect-resistant plants could affect hyperparasitoids indirectly. However, it remains to be determined whether facultative hyperparasitoids prefer to develop as primary or secondary parasitoids under field conditions.     

Relationship between different size classes of particulate matter and meteorology in three European cities

Evidence on the correlation between particle mass and (ultrafine) particle number concentrations is limited. Winter- and spring-time measurements of urban background air pollution were performed in Amsterdam (The Netherlands), Erfurt (Germany) and Helsinki (Finland), within the framework of the EU funded ULTRA study. Daily average concentrations of ambient particulate matter with a 50% cut off of 2.5 microm (PM2.5), total particle number concentrations and particle number concentrations in different size classes were collected at fixed monitoring sites. The aim of this paper is to assess differences in particle concentrations in several size classes across cities, the correlation between different particle fractions and to assess the differential impact of meteorological factors on their concentrations. The medians of ultrafine particle number concentrations were similar across the three cities (range 15.1 x 10(3)-18.3 x 10(3) counts cm(-3)). Within the ultrafine particle fraction, the sub fraction (10-30 nm) made a higher contribution to particle number concentrations in Erfurt than in Helsinki and Amsterdam. Larger differences across the cities were found for PM2.5(range 11-17 microg m(-3)). PM2.5 and ultrafine particle concentrations were weakly (Amsterdam, Helsinki) to moderately (Erfurt) correlated. The inconsistent correlation for PM2.5 and ultrafine particle concentrations between the three cities was partly explained by the larger impact of more local sources from the city on ultrafine particle concentrations than on PM2.5, suggesting that the upwind or downwind location of the measuring site in regard to potential particle sources has to be considered. Also, relationship with wind direction and meteorological data differed, suggesting that particle number and particle mass are two separate indicators of airborne particulate matter. Both decreased with increasing wind speed, but ultrafine particle number counts consistently decreased with increasing relative humidity, whereas PM2.5 increased with increasing barometric pressure. Within the ultrafine particle mode, nucleation mode (10-30 nm) and Aitken mode (30-100 nm) had distinctly different relationships with accumulation mode particles and weather conditions. Since the composition of these particle fractions also differs, it is of interest to test in future epidemiological studies whether they have different health effects.     

The ChimERA project: coupling mechanistic exposure and effect models into an integrated platform for ecological risk assessment

Current techniques for the ecological risk assessment of chemical substances are often criticised for their lack of environmental realism, ecological relevance and methodological accuracy. ChimERA is a 3-year project (2013–2016), funded by Cefic’s Long Range Initiative (LRI) that aims to address some of these concerns by developing and testing mechanistic fate and effect models, and coupling of these models into one integrated platform for risk assessment. This paper discusses the backdrop against which this project was initiated and lists its objectives and planned methodology.     

保护生态系统亟需对农药进行注册后监测

现行的农药准入政策遵循一种可控的实验性分级风险评估方法,结果很难外推到实际情况。对DDT和烟碱类杀虫剂等化合物的分析清楚地表明,化学品对生态系统的实际影响比风险评估的预计更大。因此,为了管理由人工合成的化合物对生态系统造成的实际风险,提出了目前的化学药品准入政策,并通过注册后监测来补充。这种监测对于识别化合物通过多种传播途径和暴露方式对生物体产生的直接和间接影响是至关重要的。实施注册后监测可以建立在现有的监测网络上。这一方法将解决基于区域型法规与基于暴露型法规的现行政策僵局,更重要的是,将为跨部门间的风险评估提供一个安全锁,更有可能确保我们的自然环境得到保护。
精选自Vijver, M. G., Hunting, E. R., Nederstigt, T. A.P., Tamis, W. L.M., van den Brink, P. J. and van Bodegom, P. M. (2017), Postregistration monitoring of pesticides is urgently required to protect ecosystems. Environmental Toxicology and Chemistry, 36: 860–865. doi: 10.1002/etc.3721
详情请见http://onlinelibrary.wiley.com/doi/10.1002/etc.3721/full
     

Shifting frames: mobilizing policy attention for landscape values in a Dutch urban–rural fringe

Despite framing being a powerful mechanism in policy agenda setting, the planning and policy science literature does not yet devote much attention to the analysis of interactional framing processes in policy change processes. We analyse the framing processes that preceded tipping points in the mobilization of policy attention in a Dutch peri-urban region that over time managed to position the development of landscape values on the agendas of local and regional governments, despite various institutional barriers and blockages. After identifying tipping points in the agenda-setting process, and shifts in frames and coalitions, the paper discusses why these shifts occurred. Two framing mechanisms are identified: (1) framing issues, relationships, and interaction processes in conjunction with one another and (2) resemiotizing original frames to establish a fit to the self-referential frames of targeted supporters within and outside government. The conclusion is that a research focus on human interactions at the grassroots level and on the processes of meaning construction over time reveals detailed insights about why and how structural change and transitions come about. The paper concludes with some lessons for policy-makers and planners with regard to developing a more adaptive attitude to emerging initiatives in civil society.