Contrasting responses of migration strategies in two European thrushes to climate change

Migration is a widespread strategy that enables animals to escape harsh winter conditions. It has been well documented that migration phenology in birds is changing in response to recent climate warming in the northern hemisphere. Despite the existence of large temporal and geographical scale ringing data on birds in Europe, changes in migration strategies in relation to climate warming have not been well studied, mainly because of a lack of appropriate statistical methods. In this paper, we develop a method that enables us to investigate temporal changes in migration strategies from recoveries of dead ringed birds. We estimated migration probability as the ratio between recovery probabilities of conspecific birds originating from different countries but potentially wintering in the same country. We applied this method to two European thrushes: the entirely migrant redwing Turdus iliacus , and the partially migrant blackbird T. merula . We tested for an immediate and a 1-year lagged relationship between our migration probability and climatic covariates (i.e. mean winter temperature in France and the North Atlantic Oscillation). Using ringing-recovery data collected in Finland, Germany, Switzerland and France from 1970 to 1999, we detected contrasting responses in these two species, likely related to their different migratory behaviours. Both species showed a decline in the probability for northern and eastern birds to winter in France. The entirely migratory redwing exhibited a year-to-year plastic response to climate, whereas the decline in the partially migrant blackbird was smooth, suggesting underlying genetic processes. The proposed method, thus, allows us to identify useful indicators of climatic impacts on migration strategies, as well as highlighting differences between closely related species.     

Winter use of wild bird cover crops by passerines on farmland in northeast England

Capsule Declining farmland species were more abundant in these crops which can be matched to the birds' requirements.

Aims To assess the use of seed-bearing crop by a range of bird species in winter.

Methods The study was carried out over three winters at a site in County Durham (England). Eleven bird species were represented, five of which are nationally targeted for conservation action.

Results Bird abundance was significantly higher where wild bird cover crops were present. Kale Brassica napus and Quinoa Chenopodium quinoa were the most used crop species, although cereals and linseed were also used.

Conclusion Simple crop mixtures can be designed to meet the needs of farmland bird communities. Our results suggest that seed production may be limited within government agri-environment schemes by restrictions on fertilizer use. The agronomy of seed-bearing crops for birds requires further investigation.     

The importance of passerine birds as tick hosts and in the transmission of Borrelia burgdorferi,the agent of Lyme disease: a case study from Scotland

Borrelia burgdorferi sensu lato (s.l.) is the causative agent of Lyme borreliosis, the most common tick‐borne zoonosis of humans in Europe and North America. Here, we assessed the relative importance of different passerine bird species as tick hosts and their contribution to the B. burgdorferi s.l. transmission cycle in a rural residential area in Scotland. We caught 1229 birds of 22 species during the tick‐questing season. On average, 29% carried larval ticks (0.8 larvae per individual) and 5% carried nymph ticks (0.06 nymphs per individual). All attached ticks tested were Ixodes ricinus. Using a nested‐PCR, we found that 20% of nymphs tested positive to B. burgdorferi s.l. and all these were of the genospecies Borrelia garinii. We identified two new bird species carrying infected nymphs: Eurasian Siskin Carduelis spinus and European Greenfinch Carduelis chloris. Ground‐foraging species were more important than arboreal species in hosting I. ricinus nymphs and B. burgdorferi s.l. Common Blackbirds Turdus merula were the most common hosts, with Song Thrushes Turdus philomelos, Dunnocks Prunella modularis, European Greenfinches and Chaffinches Fringilla coelebs also hosting high rates of infection.     

Effects of sex and sampling site on the relative proportion of pesticides in uropygial gland secretions of European Blackbirds (Turdus merula)

Dichlorodiphenyltrichloroethane (DDT) is a pesticide that was commonly used for decades worldwide. The use of DDT was banned in the 1970s and 1980s in Europe because of its high toxicity and persistence in the environment, bioaccumulation in living organisms and biomagnification through food webs. However, monitoring using both invasive and non-invasive methods has routinely reported the occurrence of DDT metabolites such as dichlorodiphenyldichloroethylene (DDE) in wild birds, providing valuable information about the exposure to pesticides and potential differences between species and over time. Here, we analysed the relative proportion of DDE in the uropygial gland secretions of European Blackbirds Turdus merula from two localities in southern Spain. Given the negative effects of this pollutant on animal immunity, we also tested for associations between the prevalence of haemosporidians and the relative proportion of DDE in their secretions. Relative proportions of DDE varied between sampling sites and were higher in females than in males, regardless of their age. In spite of the potential immunosuppressive effect of DDE, haemosporidian infection was not associated with DDE presence.     

Architectural design influences the diversity and structure of the built environment microbiome

Buildings are complex ecosystems that house trillions of microorganisms interacting with each other, with humans and with their environment. Understanding the ecological and evolutionary processes that determine the diversity and composition of the built environment microbiome—the community of microorganisms that live indoors—is important for understanding the relationship between building design, biodiversity and human health. In this study, we used high-throughput sequencing of the bacterial 16S rRNA gene to quantify relationships between building attributes and airborne bacterial communities at a health-care facility. We quantified airborne bacterial community structure and environmental conditions in patient rooms exposed to mechanical or window ventilation and in outdoor air. The phylogenetic diversity of airborne bacterial communities was lower indoors than outdoors, and mechanically ventilated rooms contained less diverse microbial communities than did window-ventilated rooms. Bacterial communities in indoor environments contained many taxa that are absent or rare outdoors, including taxa closely related to potential human pathogens. Building attributes, specifically the source of ventilation air, airflow rates, relative humidity and temperature, were correlated with the diversity and composition of indoor bacterial communities. The relative abundance of bacteria closely related to human pathogens was higher indoors than outdoors, and higher in rooms with lower airflow rates and lower relative humidity. The observed relationship between building design and airborne bacterial diversity suggests that we can manage indoor environments, altering through building design and operation the community of microbial species that potentially colonize the human microbiome during our time indoors.     

青藏高原东缘野生暗紫贝母生物量分配格局对高山生态环境的适应

从时空尺度研究了青藏高原东缘野生暗紫贝母(Fritillaria unibracteata)生物量分配特征对高山环境条件的生态适应。通过海拔梯度、群落类型、群落盖度、群落透光率4个变量的分析, 间接探讨了高山环境条件下水分、热量、光照和土壤养分等主要环境因子对暗紫贝母生物量分配的影响, 并主要研究了海拔梯度这一综合要素的生态效应。同时, 从时间尺度上研究了暗紫贝母不同生活史阶段的生物量分配模式, 以期了解不同发育阶段高山植物对于环境要素的适应特征。研究结果表明: 1)在一定的空间范围内, 4个环境变量中仅海拔梯度对暗紫贝母单株鳞茎生物量及总生物量的影响差异显著, 且生物量积累随海拔升高而减小。2)在空间尺度上, 海拔梯度为野生暗紫贝母生长的主要限制因子, 表明在高山地区热量条件对植物生长具有明显的制约作用, 同时不同生活史阶段的暗紫贝母其生物量分配模式对海拔梯度的响应也存在着一定的差异。2年生贝母的鳞茎生物量分配随海拔升高而降低, 叶生物量分配随之增加。3年生和4年生贝母鳞茎及叶生物量分配在不同海拔梯度上比较稳定, 而茎生物量分配随海拔升高而降低, 有性生殖(花)分配则随之而增加。各生活史阶段植株根生物量在不同海拔梯度上分配稳定。3)在时间尺度上, 不同生活史阶段贝母生物量分配模式存在显著差异。根和茎生物量分配随生活史阶段的增加而显著增加, 而鳞茎和叶生物量分配则随之显著减少。单株鳞茎生物量在3年生阶段达到最大。     

Richness and composition of terrestrial mammals vary in eucalyptus plantations due to stand age

Plantation forests substitute natural habitats and have rotation cycles of 7 years due to their high growth rates. This variation reflects on local and landscape changes, influencing habitat availability and affecting mammal communities. In this study, our general hypothesis was that the richness and composition of mammals varied in eucalyptus plantations in relation to native forest patches and in relation to the age of eucalyptus plantations. We predicted that (1) there would be lower mammalian richness and compositional differences in eucalyptus plantations compared to native vegetation due to monocultures having simplified environmental characteristics and (2) predicted that the richness and composition would vary according to eucalyptus age and that the highest values of richness would be found in plantations of up to middle age, considering that in these phases there are environmental characteristics that positively qualify these structures for a greater presence of fauna, such as the shrubby aspect of the plantations and the presence of undergrowth. We performed model selection to observe the effect of environmental variables on mammalian richness. We also performed a multivariate permutational analysis of variance, a non-metric multidimensional scaling and partitioned the beta diversity to observe how the composition was influenced by environmental variables. We found greater richness in the native vegetation compared to eucalyptus plantations. The richness of the plantations varied according to the age, with higher values up to middle age. The composition varied according to the land user/cover, with the eucalyptus age and with the management unit due to the nestedness of species. We suggest that eucalyptus plantations at early ages are more used by mammals due to the shrubby aspect of the stand, generating a positive visual effect for the search of resources and shelter, in addition to the possibility of the occurrence of grasses, some understory and lower anthropogenic disturbance.     

Highly skewed sex ratios in the critically endangered Taita thrush as revealed by CHD genes

The study of sex-ratio patterns in threatened bird species has yielded crucial information with regard to their conservation and management. In the case of sexually monomorphic species, i.e. species that cannot be sexed by their appearance, DNA-based sexing techniques are increasingly applied. We present data on the sexing of adult Taita thrushes, a critically endangered forest endemic from south-east Kenya. In addition to describing a morphometric trait that can be used to sex individuals directly upon capture, we comment on a remarkable skew in sex ratio that might have important consequences for the long-term survival of the species.     

Assessing the impact of Entry Level Stewardship on lowland farmland birds in England

Agri‐environment schemes (AES) are central to the conservation of Europe’s farmland biodiversity. The UK Government’s Public Service Agreement target seeks to reverse the decline of farmland birds in England by 2020 through the use of AES. The Entry Level Stewardship (ELS) scheme, introduced in 2005, is the first non‐competitive, broad‐uptake stewardship scheme designed to deliver simple but effective environmental management on farms throughout England. Approximately 5 million hectares of farmland are currently entered into Environmental Stewardship (ES) agreements, and given the scale of this investment it is important to verify the efficacy of ELS as a mechanism for delivering biodiversity benefits. We used spatially referenced ES agreement data to assess the influence of specific management options and combinations of options on farmland bird population changes between 2005 and 2008 derived from standardized surveys carried out on over 2000 lowland farmland 1‐km squares in England. The results showed only limited evidence for short‐term effects of ES. Only Corn Bunting Emberiza calandra and Common Starling Sturnus vulgaris showed some landscape‐specific positive associations with area under ELS management. There was also limited evidence for positive associations between specific management options and the population changes of the species at which they were aimed. The current pattern of option uptake may be limiting benefits of ELS, with boundary management accounting for over 50% of scheme compensation value. However, the time required for option maturation and the time lags in bird population responses to environmental change mean that it is too early to reach definitive conclusions about the success or failure of the scheme. The findings of this study will assist in the development of ELS by feeding into the 5‐year review scheduled for 2010 and have implications for the development of similar schemes elsewhere in Europe.     

俄罗斯东部城镇化与生态环境协调发展的时空演变特征

以俄罗斯东部地区为对象,结合PES和PSR模型分别构建其城镇化和生态环境的评价指标体系,结合熵值赋权、变异系数赋权的综合确权法测算城镇化和生态环境的发展水平,利用耦合协调度模型探讨二者协调发展程度,划分其阶段类型。研究表明：2005-2018年,（1）俄东部城镇化发展水平呈上升趋势,经济城镇化的贡献份额最大;生态环境发展水平呈小幅下降态势,生态环境压力的影响作用最大;二者的耦合协调度呈增长趋势,但整体处于基本不协调阶段,其内部由城镇化滞后转变为系统均衡发展。（2）西伯利亚联邦区的城镇化发展水平高于远东联邦区,二联邦区生态环境发展水平差距较小,西伯利亚区协调发展程度略强于远东区;西伯利亚区内部由城镇化滞后→系统均衡发展,远东区内部始终为城镇化滞后。多数联邦主体处于基本不协调阶段、高级协调的数量最少。（3）空间上,城镇化、生态环境、二者协调发展度均呈"西高东低"的格局特征,核心高值区分布在新西伯利亚州-阿尔泰边疆区-克麦罗沃州-克拉斯诺亚尔斯克边疆区-伊尔库茨克州的串联区,边缘低值区位于阿尔泰共和国和楚科奇自治区。最后探讨了促进俄东部城镇化和生态环境协调发展的具体对策。     

Variations in the distribution of genes encoding virulence and extracellular proteins in group A streptococcus are largely restricted to 11 genomic loci

Group A streptococcus (GAS) is a human pathogen associated with a wide range of human diseases that vary in symptoms and clinical severity. In this report we describe the use of a targeted low density array representing genes encoding classical virulence factors, purported virulence factors and other extracellular proteins to examine differences in the genetic profiles of 68 clinical GAS isolates. Of the 226 genes on the array (encoding 217 virulence factors or putative extracellular proteins and nine positive control house-keeping proteins) 62 had distributions that were statistically associated with specific GAS M-types. While 32 of these genes were bacteriophage related, the remaining 30 have not previously been described as bacteriophage associated. We show that these 'non-bacteriophage related' genes are found in 11 loci located in five greater chromosomal regions, often near classical GAS virulence factors, and often accompanied by genes associated with mobile genetic elements (MGEs). Many of these loci also demonstrated genetic variation within strains of the same M-type, suggesting these regions to be recombinatorial and mutational hotspots. Evidence for acquisition of genes from other species is also apparent in these loci. Our data suggests that imprecise recombination events involving MGEs not only result in acquisition of new genes, but can also result in deletion of flanking chromosomal genes. Thus MGE related events would appear to be the major contributor to variation of discrete virulence loci, which could account for the disease causing propensity of individual strains. We believe that profiling of the 11 loci could be a meaningful tool in epidemiological GAS typing studies.     

Hotspots of (sub)alpine plants in the Irano-Anatolian global biodiversity hotspot are insufficiently protected

Aim

The mountainous regions in SW Asia harbour a high number of endemic species, many of which are restricted to the high-elevation zone. The (sub)alpine habitats of the region are under particular threat due to global change, but their biodiversity hotspots and conservation status have not been investigated so far.

Location

Subalpine-alpine habitats of SW Asia.

Methods

Distribution data of all (sub)alpine vascular plant species of the region were compiled, resulting in 19,680 localities from 1672 (sub)alpine species, the majority of them being restricted to the region (76%). Six quantitative indices of species diversity were used on the basis of 0.5° × 0.5° grid cells to identify (sub)alpine hotspots. Hotspots whose surface area in the (sub)alpine zone was covered by nature reserves maximally by 10% were defined as conservation gaps.

Results

A high proportion (80%) of the endemic species of the study area is range-restricted and narrowly distributed. The results of all six indices were highly correlated. Using the top 5%, 10% and 20% richest cells supported by any index, 32, 53 and 98 cells, respectively, were identified as Hotspots. Almost 60% of these Hotspots at all three levels were identified as unprotected (i.e. constituted Conservation Gaps). Generally, only 22%, 18% and 16%, respectively, of the alpine surface area of the identified Hotspots were covered by nature reserves for the top 5%, 10% and 20% richest cells, respectively.

Main conclusions

Although the rate of protection in (sub)alpine Hotspots exceeds that of the entire region it is still insufficient, because these Hotspots are much richer in endemic and in range-restricted species, but at the same time are under high pressure of global change. Therefore, the establishment of new nature reserves with high conservation efficiency in (sub)alpine habitats with a particular focus on the identified Hotspots is strongly recommended.     

The feeding strategy of dab Limanda limanda in the southern North Sea: linking stomach contents to prey availability in the environment

The feeding strategy of dab Limanda limanda was investigated within a predefined research area in the southern North Sea for 2 years. The aims were: 1) to establish the relationship between prey availability and dab abundance, distribution, body condition and prey selection, and 2) to determine the underlying functional processes of prey choice in dab. Temporal and spatial trends of prey availability in relation to dab abundances, distribution, condition and prey selection were analysed. Temporal trends in dab condition, percentage of empty stomachs and numbers of ingested prey were apparent. In particular in the winter period 2000–2001 dab were in poor condition and prey items were only rarely found in stomachs. Similarly prey availability decreased in the environment while the abundance of dab increased. Thus, temporal changes in the nutritive state were partly thought to be attributed to density‐dependent effects. The stomach composition of dab during the two consecutive summers was mainly dominated by Pariambus typicus and Ophiura albida while in the winter period only O. albida made a significant contribution to the stomach content. Analysis of prey characteristics indicated that only prey densities in the environment significantly influenced prey choice in dab, while other characteristics such as the position of the prey in the habitat, its palatability or mobility did not have significant effects. The feeding strategy of dab thus was highly opportunistic, although trends were apparent that suggested that buried living fauna was less likely to be ingested, which was also observed in previous studies.     

Weak population differentiation in northern European populations of the endangered anadromous clupeid Alosa fallax

Examination of genetic structure among different spawning populations of the endangered twaite shad Alosa fallax showed statistically significant but weak differentiation estimated using nine microsatellite loci. Results point to substantial gene flow among the majority of individual estuary/river spawning locations, and no evidence that habitat disruption has led to increased local genetic drift.     

祁连山东段高原鼢鼠采食洞道气体研究

研究高原鼢鼠（Myospalax baileyi）洞道气体环境对了解其低氧适应机制具有重要作用。本试验在祁连山东段高寒草甸利用土壤原位气体测定仪,对高原鼢鼠采食活动洞道、非活动洞道、地表空气及无洞道土壤内的温度、氧气、二氧化碳、甲烷含量进行了连续12个月的监测。通过One-Way ANOVA检验、重复测量方差分析以及Pearson相关性分析发现,（1）高原鼢鼠活动洞道氧气含量,除10月、11月与非活动洞道无显著性差异外（P>0.05）,均显著小于非活动洞道、地表空气和无洞道土壤（P<0.05）;活动洞道二氧化碳含量,除7月、8月份与非活动洞道无显著性差异外（P>0.05）,均显著大于非活动洞道、地表空气和无洞道土壤（P<0.05）;活动洞道内甲烷含量各月均显著高于地表空气甲烷含量（P<0.05）,与非活动洞道、无洞道土壤的月季差异各异。（2）高原鼢鼠活动洞道内氧气含量的最小值和二氧化碳的最大值均出现在5月和9月,其它处理下氧气最小值和二氧化碳最大值均出现在6-8月;4个处理下甲烷含量最小值在1月与12月出现,最大值出现在5月和9月。（3）月份、处理以及月份和处理间的交互作用均对氧气、二氧化碳、甲烷含量有显著影响（P<0.05）。可见,高原鼢鼠生存在低氧、高二氧化碳和较高甲烷含量的环境中,且洞道内部的气体环境会受季节和高原鼢鼠活动的影响。     

Pressure built by DNA packing inside virions: enough to drive DNA ejection in vitro, largely insufficient for delivery into the bacterial cytoplasm

Tailed bacteriophage particles carry DNA highly pressurized inside the capsid. Challenge with their receptor promotes release of viral DNA. We show that addition of the osmolyte polyethylene glycol (PEG) has two distinct effects in bacteriophage SPP1 DNA ejection. One effect is to inhibit the trigger for DNA ejection. The other effect is to exert an osmotic pressure that controls the extent of DNA released in phages that initiate ejection. We carried out independent measurements of each effect, which is an essential requirement for their quantitative study. The fraction of phages that do not eject increased linearly with the external osmotic pressure. In the remaining phage particles ejection stopped after a defined amount of DNA was reached inside the capsid. Direct measurement of the size of non-ejected DNA by gel electrophoresis at different PEG concentrations in the latter sub-population allowed determination of the external osmotic pressure that balances the force powering DNA exit (47 atm for SPP1 wild-type). DNA exit stops when the ejection force mainly due to repulsion between DNA strands inside the SPP1 capsid equalizes the force resisting DNA insertion into the PEG solution. Considering the turgor pressure in the Bacillus subtilis cytoplasm the energy stored in the tight phage DNA packing is only sufficient to power entry of the first 17% of the SPP1 chromosome into the cell, the remaining 83% requiring application of additional force for internalization.