Patterns of activity and fatality of migratory bats at a wind energy facility in Alberta,Canada

Studying migratory behavior of bats is challenging. Thus, most information regarding their migratory behavior is anecdotal. Recently, however, fatalities of migratory bats at some wind energy facilities across North America have provided the opportunity and impetus to study bat migration at fine spatial and temporal scales. Using acoustic monitoring and carcass searches, we examined temporal and spatial variation in activity levels and fatality rates of bats at a wind energy facility in southern Alberta, Canada. Our goals were to better understand the influence of weather variables and turbine location on the activity and fatality of hoary bats (Lasiurus cinereus) and silver-haired bats (Lasionycteris noctivagans), and to use that understanding to predict variation in fatality rates at wind energy facilities and recommend measures to reduce fatalities. Overall activity of migratory bats and of silver-haired bats increased in low wind speeds and warm ambient temperatures, and was reduced when the wind was from the North or Northeast, whereas hoary bat activity increased with falling barometric pressure. Fatalities of migratory bats in general increased with increased activity of migratory bats, increased moon illumination, and falling barometric pressure and were influenced by the interaction between barometric pressure change and activity. Fatalities of silver-haired bats increased with increased activity, moon illumination, and winds from the south-east. Hoary bat fatalities increased with falling barometric pressure. Our results indicate that both the activity and fatality of migratory bats are affected by weather variables, but that species differ in their responses to environmental conditions. Spatially, fatalities were not influenced by the position of turbines within a turbine row, but were influenced by the location of turbines within the facility. Our findings have implications for our understanding of bat migration and efforts to reduce fatalities at wind energy facilities. To maximize the reduction of bat fatalities, operators of wind energy facilities could incorporate migratory bats' response to environmental variables, such as barometric pressure and fraction of moon illuminated, into their existing mitigation strategies. © 2011 The Wildlife Society.     

Environmental conditions terminate reproductive diapause and influence pheromone perception in the long‐lived moth Caloptilia fraxinella

Reproductive diapause enables long‐lived insects to time mating with environmental conditions suitable for offspring development. Plasticity in the perception of pheromones used in sexual communication may enable mate‐finding at the appropriate time of year. The moth Caloptilia fraxinella (Ely) (Lepidoptera: Gracillariidae) undergoes a 9‐month reproductive diapause, during which the male response to pheromone is plastic and is highest during the period of reproductive activity. The mechanisms controlling this pheromone response plasticity are not well‐understood, and the aim of the present study is to determine the main factors involved. In the present study, the impact of temperature, photoperiod, juvenile hormone analogue (JHA) and adult nutrition on diapause termination are tested using electroantennogram (EAG) and behavioural response to pheromone in male C. fraxinella. Eclosion in a state of reproductive diapause occurs in most males; diapause is maintained under short‐day or cool conditions indoors, or under natural conditions outdoors. Exposure to long‐day, warm conditions over a period of 4 weeks causes a small number of males to become behaviourally responsive to pheromone; a larger number of males become behaviourally responsive over a period of 3 months of post‐eclosion. Treatment with a JHA impacts male EAG and the behavioural response to pheromone during the period of reproductive diapause. A carbohydrate food source is not required by reproductively active adult male C. fraxinella to respond to pheromone and express mate location behaviours. The main factors involved in controlling male pheromone response plasticity and the implications of these factors for the C. fraxinella population in its expanded range are discussed.     

Pollen vectors and inflorescence morphology in four species of Salix

 Many plant species exhibit inflorescence morphologies intermediate between pollination syndromes and may therefore employ generalist pollination strategies. We studied how wind and insect pollination are related to inflorescence morphology in the floodplain species Salix alba, S. elaeagnos, S. daphnoides and S. triandra. Insect exclusion experiments showed that all four species were primarily pollinated by insects, but were capable of some seed set when wind was the only pollen vector. Such a generalist pollination system may provide reproductive assurance in these pioneer species. High wind pollination success was associated with slender and divided stigmatic lobes and low ovule number per catkin, which may enhance filtering capacity for airborne pollen. In contrast, species that relied more on insect pollination had robust stigmata and many ovules per catkin, which may reduce the number of insect visits necessary for pollination. Received April 18, 2002; accepted July 23, 2002 Published online: November 28, 2002 Addresses of authors: S. Karrenberg (e-mail: karrenberg@bio.indiana.edu), Department of Biology, Indiana University, Jordan Hall, 1001 East Third Street, Bloomington, IN 47405, USA. P. J. Edwards, Geobotanical Institute, ETH, Zürichbergstrasse 38, CH-8044 Zürich, Switzerland. J. Kollmann, Department of Ecology, Royal Veterinary and Agricultural University, Rolighedsvej 21, DK-1958 Frederiksberg, Denmark.     

Traveling or stopping of migrating birds in relation to wind: an illustration for the osprey

Although it is often assumed that birds strongly prefer tailwindsfor their migratory flights, we predict that a strategy of nowind selectivity (traveling independently of winds) may be morefavorable than wind selectivity (traveling on tailwind occasionsbut stopping to rest under headwind occasions) for birds withlow energy costs of travel relative to rest and for birds thatcannot use stopover time for efficient fuel deposition. We testthis prediction by analyzing the daily traveling or stoppingas recorded by satellite tracking of five ospreys Pandion haliaetus,a species often using energy-saving thermal soaring, duringtheir migration between northern Europe and Africa. Besideswind, precipitation is another weather factor included in theanalyses because thermal soaring migrants are expected to stopand rest in rainy weather. In logistic regression analyses,taking into account the effects of latitude, behavior on previousday, season, date, and individual for discriminating betweentraveling and stopping days, we found a lack of influence ofwinds, suggesting that the ospreys travel or stop without regardto wind. This lack of wind selectivity under light and moderatewinds is in agreement with our prediction. We expect a low degreeof wind selectivity and thus regular flights under headwindsalso among other types of birds that cannot use stopping timefor efficient foraging and fuel deposition. We also found anunexpected lack of influence of precipitation, possibly becauseof relatively few instances with rainfall in combination withpoor geographic precision for estimates of this weather variable.     

Genetic variation and structure in the Mediterranean shrubs Myrtus communis and Pistacia lentiscus in different landscape contexts

Studies concerning different habitat configurations can provide insights into the complex interactions between species’ life‐history traits and the environment and can help to predict patterns in population genetics. In this study, we compared patterns of genetic variation in two Mediterranean shrub species (Myrtus communis and Pistacia lentiscus) that co‐occur in populations within three contrasting landscape contexts: continuous, fragmented‐connected and fragmented‐isolated populations. Analysing variation at microsatellites loci, our results revealed weak responses to the landscape contexts. We rather found a population‐specific response in both study species. However, despite both study species sharing similar levels of genetic diversity, Myrtus displayed higher levels of homozygosity and genetic differentiation among populations, stronger patterns of within‐population spatial genetic structure, lower values of mutation‐scaled effective population size and stronger evidence for recent genetic bottlenecks than Pistacia. This result highlights the influence of past events (e.g. historical connectivity, fluctuations in population size) and local factors (e.g. microhabitat availability for recruitment, habitat quality, plant density, native fauna) and that the landscape configuration per se (i.e. fragment size and/or isolation) might not completely determine the species’ genetic patterns.     

Vibrational noise from wind energy-turbines negatively impacts earthworm abundance

Human activities often impact the sensory environment of organisms. Wind energy turbines are a fast-growing potential source of anthropogenic vibrational noise that can affect soil animals sensitive to vibrations and thereby alter soil community functioning. Larger soil animals, such as earthworms (macrofauna, > 1 cm in size), are particularly likely to be impacted by the low-frequency turbine waves that can travel through soils over large distances. Here we examine the effect of wind turbine-induced vibrational noise on the abundance of soil animals. We measured vibrational noise generated by seven different turbines located in organically-farmed crop fields in the Netherlands. Vibratory noise levels dropped by an average of 23 ± 7 dB over a distance of 200 m away from the wind turbines. Earthworm abundance showed a strong decrease with increasing vibratory noise. When comparing the nearest sampling points in proximity of the wind energy turbines with the points furthest away, abundance dropped on average by 40% across all seven fields. The abundance of small-sized soil animals (mesofauna, < 10 mm in size) differed between crop fields, but was not related to local noise levels. Our results suggest that anthropogenic vibratory noise levels can impact larger soil fauna, which has important consequences for soil functioning. Earthworms, for instance, are considered to be crucial ecosystem engineers and an impact on their abundance, survival and reproduction may have knock-on effects on important processes such as water filtration, nutrient cycling and carbon sequestration.     

基于功能和谱系视角分析繁殖留鸟对风机的响应

风电作为清洁可再生绿色能源越来越受到世界各国的重视,其建设规模也在不断扩大,导致风电建设与鸟类保护的矛盾进一步凸显,如何协调风电发展与物种保护已成为生态学家和保护生物学家关注的热点主题。为了探究风机对鸟类物种、功能和谱系的影响,本研究于2019年1、3、4、5月,采用样线法对连山风电场的鸟类多样性进行了4次调查。根据样线离风机距离的远近设置4个梯度: 100～300 m有6条样线,300～500 m 有13条样线,500～700 m 有8条样线,>700 m 有5条样线。结果表明: 本次调查中记录了繁殖留鸟76种,隶属于11目31科,目、科中数量最多是雀形目(53种)和画眉科(12种)。鸟类物种丰富度、功能丰富度(FRic)和谱系多样性(Faith PD)随着离风机距离的增加呈增加趋势: 在500 m以内未显著增加,500 m外呈显著增加趋势;鸟类群落水平的扩散能力呈现出增加趋势。鸟类群落的平均成对功能和谱系距离的标准化效应值(SES.MFD和SES.MPD)均小于0,其中显著低于随机值的样线占比约为50%(P<0.05)。风力发电机对鸟类物种、功能和谱系的影响主要在前500 m的距离;本研究的4个梯度中,鸟类群落的功能和谱系结构均表现为聚集特征。研究证实,风机对鸟类的影响是多维度的,在评估风机对鸟类群落的影响时仅考虑物种多样性可能难以提供全面的信息。     

The amounts and properties of transported air at two norwegian stations as functions of wind direction and weather type

Based on monthly means of climatic variables during the period 1937–65, the climate at two Norwegian meteorological stations in January and July was classified by principal component analysis. The new variables were interpreted as pairs of alternating weather types, or airmasses. Four airmasses were identified, covering 20–30% of the transported air at each station. The significance, properties and amounts of air transported by each airmass was calculated and distributed according to wind direction. Differences between air circulation pattern and airmass distribution and properties during the summer and winter season were pointed out. One of the major differences is the tendency to form high pressure over inland areas in winter vs. low pressure in the summer season.