Search

Biological invasions are a major human induced global change that is threatening global biodiversity by homogenizing the world's fauna and flora. Species spread because humans have moved species across geographical boundaries and have changed ecological factors that structure ecosystems, such as nitrogen deposition, disturbance, etc. Many biological invasions are caused accidentally, as a byproduct of human travel and commerce driven product shipping. However, humans also have spread many species intentionally because of perceived benefits. Of interest is the role of the recent exponential growth in information exchange via internet social media in driving biological invasions. To date, this has not been examined. Here, we show that for one such invasive species, goldenrod, social networks spread misleading and incomplete information that is enhancing the spread of goldenrod invasions into new environments. We show that the notion of goldenrod honey as a "superfood" with unsupported healing properties is driving a demand that leads beekeepers to produce goldenrod honey. Social networks provide a forum for such information exchange and this is leading to further spread of goldenrod in many countries where goldenrod is not native, such as Poland. However, this informal social information exchange ignores laws that focus on preventing the further spread of invasive species and the strong negative effects that goldenrod has on native ecosystems, including floral resources that negatively impact honeybee performance. Thus, scientifically unsupported information on "superfoods" such as goldenrod honey that is disseminated through social internet networks has real world consequences such as increased goldenrod invasions into novel geographical regions which decreases native biodiversity.

Aim: In the current Anthropocene, many ecosystems are being simultaneously invaded by multiple alien species. Some of these invasive species become more dominant and have greater environmental impacts than others. If two potentially dominant species invade the same area, the combined impact has been reported to be either (a) domination by one species, that is, the competitive dominance of one invader, or (b) invasion meltdown, where the combined impact is much greater, that is, a synergistic effect. We studied the effects of the invasion of two alien plant species that are known to strongly decrease native plant species diversity: the Persian walnut Juglans regiaand goldenrod Solidago canadensis. Location: We examined native vegetation diversity in abandoned fields (in Poland) where neither species had invaded, only one species had invaded, and both species had invaded. Methods: Field survey data were analysed using generalized linear mixed models and ordination techniques. Results: When goldenrod invaded alone, it caused a larger decrease in species richness and cover (74%) than when walnut invaded alone (58%). When walnut and goldenrod co-occurred in abandoned fields, walnut was dominant and strongly decreased goldenrod density by 87%. However, the combined impact on native species diversity was much lower (15% decrease in native plant diversity) than when either goldenrod or walnut invaded alone. Main conclusions: In contrast to many other studies, our study does not support the occurrence of an invasion meltdown. Instead, our results show that even when one invader dominates, its negative effect on plant diversity can be strongly modified by the presence of another invasive species.

Why do some species occur in small, restricted areas, while others are distributed globally? Environmental heterogeneity increases with area and so does the number of species. Hence, diverse biotic and abiotic conditions across large ranges may lead to specific adaptations that are often linked to a species’ genome size and chromosome number. Therefore, a positive association between genome size and geographic range is anticipated. Moreover, high cognitive ability in organisms would be favored by natural selection to cope with the dynamic conditions within large geographic ranges. Here, we tested these hypotheses in birds—the most mobile terrestrial vertebrates—and accounted for the effects of various confounding variables, such as body mass, relative brain mass, and geographic latitude. Using phylogenetic generalized least squares and phylogenetic confirmatory path analysis, we demonstrated that range size is positively associated with bird genome size but probably not with chromosome number. Moreover, relative brain mass had no effect on range size, whereas body mass had a possible weak and negative effect, and range size was larger at higher geographic latitudes. However, our models did not fully explain the overall variation in range size. Hence, natural selection may impose larger genomes in birds with larger geographic ranges, although there may be additional explanations for this phenomenon.

Habitat fragmentation is considered as major threat to biodiversity worldwide. Biodiversity can be described as taxonomic, functional and phylogenetic diversity. However, the effect of forest fragmentation on taxonomic, phylogenetic and functional diversity is barely understood. We compare the response of taxonomic (species richness), phylogenetic and functional diversity of birds to forest fragmentation. We hypothesised that with increasing forest patch isolation and/or decreasing patch size the diversity of birds decreases but only if certain thresholds of fragmentation metrics are reached. Specifically, we hypothesized that out of the three diversity components the taxonomic diversity is the most sensitive to forest fragmentation, which means that it starts declining at larger patch size and higher connectivity values than phylogenetic and functional diversity do. We compared the three biodiversity metrics of central European bird species in a large set of forest patches located in an agricultural landscape. General additive modeling and segmented regression were used in analyses. Habitat fragmentation differentially affected studied biodiversity metrics. Bird taxonomic diversity was the most responsive towards changes in fragmentation. We observed an increase in taxonomic diversity with increasing patch area, which then stabilized after reaching certain patch size. Functional diversity turned out to be the least responsive to the fragmentation metrics and forest stand characteristics. It decreased linearly with the decreasing isolation of forest patches. Apart from the habitat fragmentation, bird taxonomic diversity but not phylogenetic diversity was positively associated with forest stand age. The lower share of dominant tree species, the highest taxonomic diversity was. While preserving a whole spectrum of forests (in terms of age, fragmentation and size) is important from the biodiversity perspective, forest bird species might need large, intact, old-growth forests. Since the large and intact forest becomes scarcer, our study underscore their importance for the preservation of forest specialist species.

The increased introduction of non-native species to habitats is a characteristic of globalisation. The impact of invading species on communities may be either linearly or non-linearly related to the invaders’ abundance in a habitat. However, non-linear relationships with a threshold point at which the community can no longer tolerate the invasive species without loss of ecosystem functions remains poorly studied. We selected 31 wet meadow sites that encompassed the entire coverage spectrum of invasive goldenrods, and surveyed the abundance and diversity of pollinating insects (bees, butterflies and hover flies) and native plants. The species richness of native plants decreased linearly with goldenrod cover, whereas the abundance and species richness of bees and butterflies decreased non-linearly with increasing goldenrod cover. However, no statistically significant changes across goldenrod cover were noted for the abundance and species richness of hover flies. Because of the non-linear response, goldenrod had no visible impact on bees and butterflies until it reached cover in a habitat of about 50% and 30–40%, respectively. Moreover, changes driven by goldenrod in the plant and pollinator communities were related to species loss rather than species replacement. We demonstrated that the impact of goldenrod cover on a habitat is not instantaneous. Habit management aimed at preventing the invasion process and alleviating its impact should take into account that, for the non-linear relationships, the negative impact can appear rapidly after crossing the threshold point.

The response of animals to the edge reveals the potential mechanism underlying the impact of invasive plants on native pollinators. Many invasive plants flower only during a part of the growing season, which creates a temporal pattern of the availability of resources. This can lead to the emergence or disappearance of the edge effect in the pollinator community in the patches dominated by alien plants. We tested whether the variability in the supply of flower resources created by dense stands of flowering invasive goldenrods could create a temporal edge effect for pollinating insects in a grassland landscape. We surveyed pollinator communities along transects perpendicular to the goldenrod-grassland edge. To understand the variation in edge effects, we surveyed the number of flowers, which are the main food resources for pollinators. We found positive edge responses of abundance and species richness of all pollinator groups from the edges to the grassland interior before the goldenrod flowering period. During the goldenrod flowering period abundance and species richness of bees showed a neutral edge response, the response of butterflies and hoverflies towards the centre of the goldenrod patch were negative and positive respectively. Our results revealed that the emergence of the edge effect in a pollinating insect community is associated with temporal usability of invasive plants as a food source. Thus, the combined outcome of the available resources and invasion of alien plants can help to understand the edge effect on pollinator distributions in the invaded landscapes.

Bee-eaters (Meropidae) are considered agricultural pests and their presence provokes conflicts with beekeepers and farmers who rely on the pollination services of honey bees. This problem is often deal with through the mass killing of the birds, even though the quantitative evidence on the impact of bee-eaters on honey bee colonies is scarce. The current paper reports the performance of honey bee colonies protected with mist nets from migrating flocks of European bee-eaters Merops apiaster in Israel. In the study the weight gains of bee hives surrounded by mist nets were 6.44 times higher than that of unprotected hives (26.4 kg vs. 4.1 kg). The results confirmed that bee-eaters locally pose a problem to apiaries and potentially to the crops that require pollination. Mist- netting appeared to be an effective mitigation method for alleviating conflicts between beekeepers and bee-eaters. However, the study also showed that bees were able to differentiate between their main predator and other avian species trapped in mist nets and stung only bee-eaters. Moreover, the bees were targeting the most vulnerable body parts of birds which resulted in some bird fatalities. Therefore, due to accidental mortal- ity of birds, mist-netting is recommended only on the migratory routes in cases when bee hives cannot be moved to other areas.

Unpredictable resources in seasonal environments may favour innovative individuals that efficiently explore and exploit such resources. We tested the hypothesis that potential intraspecific abundance is a more powerful predictor of detection of a novel food source than interspecific abundance and predation risk. The hypothesis was tested using latency of Great Tits Parus major to find bird-feeders in relation to the abundance of Great Tit and other birds, as well as cats recorded close to novel feeders in urban and rural habitats. Data were collected during winter 2013/2014 in eight cities and nearby rural areas across Poland. Generalized linear models, multimodel inference and hierarchical partitioning showed that the probability that Great Tits used a novel birdfeeder was positively correlated both with the number of Great Tits and all other tits combined in the vicinity of feeders. Latency in feeder usage was negatively related to the number of conspecifics, and it was less strongly negatively related to the number of other tits and the abundance of all other species. The effect of the number of other tits interacted with the environment; the number of tits positively correlated with latency in rural areas, while this relationship was negative in urban areas. Latency until arrival at a feeder was shorter for males than for females. The effect of cats at feeders on bird behaviour was statistically non-significant. Thus, latency until arrival at novel birdfeeders was predicted by local population size and abundance of other bird species, but not mammalian predators, and this relationship may be altered by the environment.

The most negative impacts of roads on bats are increased mortality caused by collisions with vehicles, noise pollution reducing both communication and foraging, and barriers to movement. To test the effect of roads and traffic on the occurrence and foraging habits of bats in forested landscapes in western Poland we compared 53 sites located along local asphalt roads of low to medium traffic volume with paired reference sites on unsurfaced forest roads. Acoustical monitoring systems with Anabat detectors were used at night to detect bats at all sites. Overall, we found a strongly significant preference of bats for local asphalt roads; 640 bat passes were recorded at asphalt roads but only 271 at reference sites. Furthermore, significantly more bat taxa, longer activity and a greater frequency of feeding buzzes (calls used during foraging) were also recorded at asphalt roads. However, significant benefits were not shown for all species. This study clearly shows that local asphalt roads in forested landscapes are important foraging areas for several bat species.

Aim Landscape composition and spatial configuration of habitat patches are important determinants of biodiversity in fragmented semi-natural habitats spread across agricultural landscapes. However, little attention has been paid to man-made structures that can moderate spatial processes affecting pollinator communities. In a large-scale study, we explored the importance of railway embankments for the turnover of pollinator species in agricultural landscapes. Because species differ in vulnerability to landscape composition and patch configuration, we also accounted for body size as well as food specialization of pollinators. Location Krakow area, Poland. Methods We sampled pollinating insects (bees, butterflies and hoverflies), at 25 study sites located along railway lines in the region of Krakow, Poland. Control grasslands for the embankments included 19 patches, located among crop fields, in which pollinators were sampled. We assessed the relationships between dissimilarity and distance for bee, butterfly and hoverfly trait groups on embankments and grasslands using Moran's Eigenvector Maps. Results The dissimilarity for food-non-specialized bees on embankments was spatially structured: sites that were closer together were also less dissimilar in their community composition than more distant ones. Dissimilarity was also spatially aligned for large-bodied butterflies and hoverflies on embankments. The species dissimilarity of pollinators divided into trait-based groups was not spatially structured on grasslands. Main conclusion Our study highlights the potential function of railway embankments as corridors for at least some pollinator populations. Landscape managers should include railways in green networks to improve spatial processes linked with the distribution and turnover of pollinator species in agricultural landscapes. Thus, railway embankments and their correct management may be a good example of man-made alterations in the environment that meet the demands of both civilization and biodiversity conservation.

Selection of kill sites is an important part of predation. In human-modified habitats, anthropogenic landscape features may increase or decrease hunting efficiency of predators. We investigated which habitat attributes increase predation success in wolf Canis lupus hunting for ungulates in an intensively managed forest of western Poland. We used GPS telemetry and snow-tracking to locate kill sites. Habitat characteristics of 66 kill sites differed from those of 66 non-kill sites. Proximity of habitat edges, waterbodies or watercourses, and forestry fences increased the probability of a successful kill. Kill-site characteristics differed between the two main prey species. Red deer Cervus elaphus were killed mostly near habitat edges and water (81% and 36% of kill sites, respectively), and in younger forest stands. Roe deer Capreolus capreolus were killed primarily near forestry fences (43% of kill sites). We conclude that forestry management may influence prey vulnerability and prey selection by wolves. Management practices create environmental traps (e.g. fences, habitat edges) that help wolves to kill their prey. This knowledge can be applied in forest management to facilitate ungulate-damage prevention, for instance by small instead of large-scale clear-cuts. Our results also suggest that keeping some natural habitat elements such as swamps, ponds or fallen trees may positively correlate with wolf hunting efficiency and possibly add to the ungulate control in commercial forests. Therefore, the presence of wolves in commercial forests may be a situation with benefits for forestry and wolf conservation.

Valuable habitats in various spatial configurations are essential for maintaining biodiversity across highly fragmented urban landscapes. In a large-scale study, we explored the value of human-made structures - river levees - as valuable habitats that support large populations of plants and butterflies and affects the spatial turnover of species within an urban landscape. The most significant environmental variables affecting plant and butterfly populations on levees were also examined. The richness of native plant species was about 25% greater on levee transects than on control grassland transects. However, the richness and abundance of butterflies on levees were the same as on grassland sites. Among environmental factors, urban area cover negatively affected the richness of native plant species. Shrub cover decreases the richness and abundance of butterfly species. In addition, high mowing intensity had a negative influence on abundance. Community dissimilarity of plants on levees was affected by spatial variables. Our study is the first to highlight levees as significant habitats for plant and herbivorous insect persistence, and their potential function for plant dispersal.

Plant invasions are affected by many factors that must be favourable in order for invasions to occur. Factors can be grouped into three major categories: propagule pressure, biotic factors and abiotic characteristics; all may be moderated by human activity. However, studies examining all factors simultaneously are rare, and most are limited to a single factor. This hampers our understanding of the mechanisms driving invasions. In recent decades, an alien walnut (Juglans regia) has become invasive in Central Europe due to an increase in the populations of native dispersers, rooks (Corvus frugilegus) and political changes that have resulted in the abandonment of farmland. Here, we test whether increased propagule pressure resulting from the presence of seed-bearing walnuts in abandoned fields interacts with native forest seed-dispersing animals (biotic factors), landscape structure and management, and passive secondary dispersal by gravity (abiotic factors) to facilitate the further invasion of walnuts into forests. Seed-dispersing animals were observed visiting walnuts growing in abandoned fields and in human settlements. Walnuts and seed dispersers were surveyed in 102 forest patches. Forest characteristics were examined, and field experiments examining passive dispersal were conducted. Walnut seeds were carried into forests by native birds, jays (Garrulus glandarius). Jays harvested seeds from both wild walnuts growing in abandoned fields and walnuts planted in human settlements. The density of walnuts in forest patches was correlated with jay density. Forest occupancy by walnuts and walnut densities were correlated with the cover of abandoned fields and human settlements containing seed-bearing walnuts. Secondary seed dispersal also affected forest colonization. Walnut seeds hidden by native rooks in sloping, arable fields may be transported passively to forest edges. Synthesis. Our results show that this invasion is a multifaceted process in which human-related alterations to propagule pressure and biotic and abiotic factors have led to the spread of alien walnuts from human settlements and abandoned fields into forest ecosystems. Thus, politically related land use changes can create an invasion debt that causes unexpected linkages among the invasive plant, native dispersers, land management and topography that together can cause cascading changes in ecosystems.

The components of foraging behaviour and success of adult and juvenile Grey Heron Ardea cinerea were studied at the Dobczyce Reservoir (southern Poland) in July and September 2015. Juvenile and adult birds moved at similar rates during both months. Fish capture attempt rate was significantly higher for juvenile birds than for adults in July but not in September. Capture rate and foraging success probability (number of captures over all attempts) was significantly lower in juveniles in July but not in September. The foraging success probability of juveniles increased from July to September. Adult and juvenile birds caught mostly small fish, with no differences in size. However, handling time in juvenile birds was much longer than in adults in July but not in September, after controlling for differences in prey size. Thus, juvenile Grey Heron increased their efficiency of catching fish from July to September by reducing the number of mistakes, probably as a result of experience.

Summary To counteract the decline of farmland biodiversity in Europe, it is crucial to recognize habitats that are hot spots. Old rural settlements (e.g. villages) may be such important habitats, although these presumably biodiversity-rich habitats have received little attention. Socio-economic changes in central-eastern Europe since 1989 mean that old homesteads and farmsteads are being replaced by new ones. We investigated bird species composition, richness and abundance at three spatial scales (single rural property, village and landscape) in the farmland of Poland to test: (i) their association with age (built before vs. after 1989) and type of property (farmstead vs. homestead), (ii) their relationship with the increasing share of new homesteads at the village scale and (iii) the difference in diversity between the village environment and four other environments (open fields, forest–field ecotones, forests and towns) at the landscape scale. At the single property scale, 15 out of 33 species preferred old farmsteads, while only one species preferred new homesteads. Old properties hosted a higher number of species and individuals than new ones, and farmsteads hosted a higher number of species than homesteads. At the village scale, bird species richness and abundance were markedly negatively associated with the proportion of new homesteads. At the landscape scale, species composition differed between villages and the other environments, and villages had the highest average bird abundance. Synthesis and applications. Rural villages and old farmsteads are important habitats for many farmland birds; thus, the increasing number of new homesteads not associated with farmland production will likely lead to a substantial further decline of farmland bird numbers and biodiversity. To counteract this process, we recommend (i) implementing educational programmes to develop rural residents’ awareness about the importance of farmsteads and homesteads for biodiversity, (ii) including villages and farmsteads and consideration of bird-friendly habitats within these as part of EU conservation policies and (iii) compensating for changes in the structure of rural villages by increasing the amount of similar alternative habitats in the surrounding landscape.

Every species has certain habitat requirements, which may be altered by interactions with other co-occurring species. These interactions are mostly ignored in predictive models trying to identify key habitat variables correlated with species population abundance/occurrence. We investigated how the structure of the urban landscape, food resources, potential competitors, predators, and interaction between these factors influence the abundance of house sparrow Passer domesticus and the tree sparrow P. montanus in sixty 25 ha plots distributed randomly across residential areas of the city of Poznań (Poland). The abundance of the house sparrow was positively correlated with the abundance of pigeons but negatively correlated with human-related food resources. There were significant interaction terms between abundances of other urban species and habitat variables in statistical models. For example, the abundance of house sparrow was negatively correlated with the abundance of corvids and tree sparrows but only when food resources were low. The abundance of tree sparrows positively correlated with density of streets and the distance from the city center. The abundance of this species positively correlated with the abundance of corvids when food resources were low but negatively correlated at low covers of green area. Our study indicates that associations between food resources, habitat covers, and the relative abundance of two sparrow species are altered by the abundance of other urban species. Competition, niche separation and social facilitation may be responsible for these interactive effects. Thus, biotic interactions should be included not only as an additive effect but also as an interaction term between abundance and habitat variables in statistical models predicting species abundance and occurrence.

How do young birds achieve spatial knowledge about the environment during the initial stages of their life? They may follow adults, so gaining social information and learning; alternatively, young birds may acquire knowledge of the environment themselves by experiencing habitat and landscape features. If learning is at least partially independent of adults then young birds should respond to landscape composition at finer spatial scale than adults, who possess knowledge over a larger area. We studied the responses of juvenile, immature and adult Caspian Gull Larus cachinnans to the same habitat and landscape variables, but at several spatial scales (ranging from 2.5 to 15 km), during post-breeding period. We surveyed 61 fish ponds (foraging patches) in southern Poland and counted Caspian gulls. Juvenile birds responded at finer spatial scales to the factors than did adults. Immature birds showed complicated, intermediate responses to spatial scale. The abundance of juvenile birds was mostly correlated with the landscape composition (positively with the cover of corridors and negatively with barriers). Adult abundance was positively related to foraging patch quality (fish stock), which clearly required previous spatial experience of the environment. The abundance of all age classes were moderately correlated with each other indicating that social behaviour may also contribute to the learning of the environment. This study shows that as birds mature, they respond differently to components of their environment at different spatial scales. This has considerable ecological consequences for their distribution across environments.

Estimation of the population size and distribution of individuals is crucial in ecological studies. In many territorial animals, e.g., birds, territory mapping is the method believed to produce absolute and accurate estimators of population size (number of breeding territories). However, the results are highly variable among observers because interpreting maps is subjective and might depend on previous experience, map scale and bulk of data in the map. This technique is also highly laborious. In this work, we present a new approach to the analysis of bird species maps using spatial hierarchical clustering. Observers mapped birds and noted details of their behaviour in a 429 ha forest-grassland mosaic plot in the Beskid Maly Mountains, Poland. Spatial hierarchical clustering uses only a distance criterion to establish a cluster that is considered a proxy of bird territory. The mathematically established (CrimeStat software) number of territories is compared with the number of territories delineated in a traditional manner by three map analysts experienced in field surveys and the method. The map analysts differed in the number of delineated territories. The average coefficient of variation was 64% (range: 0–173%) and intraclass correlation coefficient was lower than for the computer algorithm and mean estimates of the map analysts. Spatial hierarchical clustering estimated the numbers of territories inside the 95% confidence interval for means calculated using the estimates for each species from map analysts. The relative rank abundance (order of the number of territories estimated by spatial hierarchical clustering) was similar to the results estimated by map analysts as indicated by the Wilcoxon paired test and intraclass correlation coefficient which exceeded a value of 0.9. Higher-order clusters (clusters of “territories”) were also found. Although the presented method uses only the distance criterion, it produces results comparable to the traditional interpretation from maps. The advantage of the presented approach is that it generates repeatable results that are free of subjectivity and independent of observer experience and might supply additional information on the distribution of the territories and perhaps their size. The method might also identify areas of high suitability and can be successfully applied to any territorial animal. Further development should be directed towards inclusion of animal behaviour and simultaneous records of different individuals in the algorithm that calculates clusters.

Roads may have an important negative effect on animal dispersal rate and mortality and thus the functioning of local populations. However, road verges may be surrogate habitats for invertebrates. This creates a conservation dilemma around the impact of roads on invertebrates. Further, the effect of roads on invertebrates is much less understood than that on vertebrates. We studied the effect of roads on butterflies by surveying abundance, species richness and composition, and mortality in ten grassland patches along high-traffic roads (∼50–100 vehicles per hour) and ten reference grassland patches next to unpaved roads with very little traffic (

© 2018 Elsevier Ltd With the human population increasing there have been losses in biodiversity. A common feature of mankind is religious beliefs with various associated positive and negative consequences for biodiversity. Religion also has associated religious sites, many of which have a long history. The role of churches in benefitting biodiversity has not received attention. To examine the impact of churches we measured the taxonomic, phylogenetic and functional diversity of birds around Christian churches and compared this with matched farmsteads. We surveyed 101 churches and equal number of farmsteads in villages of southern Poland. We measured structural and compositional characteristics (e.g. number of trees, shrubs, number of buildings and height) at both churches and farmsteads. General additive models, ordination and rarefactions methods were used in data analysis. Species richness, abundance and phylogenetic diversity were each higher at churches than at farmsteads. The species composition differed between building types but functional diversity was similar at both types of buildings. Bird species richness and abundance were correlated with the church's age. Previous studies showed village farmsteads supported high species diversity, thus our current findings that churches are richer show they may increase bird diversity in studied villages. We suggest that the green surroundings and tall towers create strong environmental gradient that enhances species richness, functional and phylogenetic diversity. There are over ten thousand churches in Poland, and similar places of worship are present in many religions, thus this habitat may be important for sustaining local taxonomic, functional and phylogenetic biodiversity in different global areas.

Metapopulation functioning in the context of landscape and habitat structure is generally well understood. However, in human-transformed landscapes, human disturbance may affect not only a species of interest but also biotic interactions in which that species is engaged, which has been rarely studied at multiple spatial scales. We tested (1) the associations between local (habitat and micro-habitat) and landscape factors and the occurrence and abundance of the land snail Cepaea nemoralis and two of its predators (thrushes and mice); and (2) the hypothesis that human disturbances modify associations between C. nemoralis and its predators. We surveyed snail colonies in rural landscapes of Poland. Generalized linear mixed models were used to test the stated hypotheses. At the landscape scale, the occurrence of C. nemoralis colonies was positively related to the cover of suitable habitats, fallow/waste land, and road length in the surrounding landscape. Bird predator abundance was positively correlated with the occurrence of snail colonies, mostly at sites with a high human impact, and was negatively correlated with snail abundance at sites with low human disturbance. Snail occurrence and abundance at the micro-habitat scale were positively correlated with variables describing the proximity of shelter and humidity. Avian predation pressure was negatively correlated with forest and settlement cover, whereas rodent predation pressure was positively associated with snail abundance and was negatively correlated with bird abundance. Human disturbance at the habitat and landscape scales benefited C. nemoralis through the creation of suitable habitats and scaling down of avian predation pressure. Conditions related to shelter and humidity were linked to the distribution and abundance of snails at the micro-habitat scale.

Same-sex sexual behaviour has been noted among social animals. However, because of the large number of observations necessary, data from controlled experiments are lacking. In this study, we performed experiments to evaluate the effects of male and female removal in colonies of the feral pigeon (Columba livia f. urbana). After the experimental removal of males, five long-lasting female-female pairs occurred. We found that those pairs could successfully raise offspring in a manner comparable to female-male pairs. Same-sex sexual behaviour and pairing in females is thus a better alternative to postponed breeding or breeding alone without the help of a partner. In contrast, in the case of female-removal experiments, same-sex pairing behaviour occurred in males as a temporary phenomenon with characteristic mutual aggression. Additionally, under a male-biased sex ratio, we observed father-son and father-daughter copulations. To the best of our knowledge, these results are the first obtained under controlled experimental conditions which demonstrate that the sex ratio of a population can shift the social structure and cause cooperative same-sex breeding behaviour to arise in a monogamous species.

Semi-natural wet meadows are threatened by drainage, the abandonment of traditional management and climate change. The large blue butterflies Maculinea teleius and M. nausithous are flagship species associated with wet meadows and are the targets of many conservation programmes. However, there is little knowledge on the impact of natural catastrophes, such as floods, on the persistence of these butterflies. In our study we tested how a flood that resulted in the temporary inundation of meadows affected populations of M. teleius and M. nausithous. Studies were conducted in two consecutive seasons of 2009 (with ‘normal’ weather) and 2010 (with extreme rainfall and a consequent flood in May) in a wet meadow complex located in the Vistula River valley in southern Poland. In both years the abundance of adults was estimated for each local habitat patch (n = 55) within sympatric metapopulations of both species. Additionally, in June 2010, i.e. directly after the flood and shortly before the flight period, a total of 754 Myrmica ant nests in 10 habitat patches (6 inundated vs. 4 not inundated) were checked for the presence of Maculinea larvae and pupae. We found no impact of inundation on year-to-year changes in adult population sizes. The probability of occurrence of Maculinea larvae and pupae in ant nests was higher in temporarily inundated meadows. Our results indicate that temporary inundation occurring after long-term downpours does not negatively affect the investigated species even during the larval period in ant nests at ground level. This provides an argument against drainage works in wet meadows with Maculinea butterflies.

The type of matrix, the landscape surrounding habitat patches, may determine the distribution and function of local populations. However, the matrix is often heterogeneous, and its various components may differentially contribute to metapopulation processes at different spatial scales, a phenomenon that has rarely been investigated. The aim of this study was to estimate the relative importance of matrix composition and spatial scale, habitat quality, and management intensity on the occurrence and density of local populations of two endangered large blue butterflies: Phengaris teleius and P. nausithous. Presence and abundance data were assessed over two years, 2011-12, in 100 local patches within two heterogeneous regions (near Kraków and Tarnów, southern Poland). The matrix composition was analyzed at eight spatial scales. We observed high occupancy rates in both species, regions and years. With the exception of area and isolation, almost all of the matrix components contributed to Phengaris sp. densities. The different matrix components acted at different spatial scales (grassland cover within 4 and 3 km, field cover within 0.4 and 0.3 km and water cover within 4 km radii for P. teleius and P. nausithous, respectively) and provided the highest independent contribution to the butterfly densities. Additionally, the effects of a 0.4 km radius of forest cover and a food plant cover on P. teleius, and a 1 km radius of settlement cover and management intensity on P. nausithous densities were observed. Contrary to former studies we conclude that the matrix heterogeneity and spatial scale rather than general matrix type are of relevance for densities of butterflies. Conservation strategies for these umbrella species should concentrate on maintaining habitat quality and managing matrix composition at the most appropriate spatial scales.

1. Wild bees are one of the most important groups of pollinators in the temperate zone. Therefore, population declines have potentially negative impacts for both crop and wildflower pollination. Although heavy metal pollution is recognized to be a problem affecting large parts of the European Union, we currently lack insights into the effects of heavy metals on wild bees. 2. We investigated whether heavy metal pollution is a potential threat to wild bee communities by comparing (i) species number, (ii) diversity and (iii) abundance as well as (iv) natural mortality of emerging bees along two independent gradients of heavy metal pollution, one at Olkusz (OLK), Poland and the other at Avonmouth (AVO), UK. We used standardized nesting traps to measure species richness and abundance of wild bees, and we recorded the heavy metal concentration in pollen collected by the red mason bee Osmia rufa as a measure of pollution. 3. The concentration of cadmium, lead and zinc in pollen collected by bees ranged from a background level in unpolluted sites [OLK: 1·3, 43·4, 99·8 (mg kg−1); AVO: 0·8, 42·0, 56·0 (mg kg−1), respectively] to a high level on sites in the vicinity of the OLK and AVO smelters [OLK: 6·7, 277·0, 440·1 (mg kg−1); AVO: 9·3, 356·2, 592·4 (mg kg−1), respectively]. 4. We found that with increasing heavy metal concentration, there was a steady decrease in the number, diversity and abundance of solitary, wild bees. In the most polluted sites, traps were empty or contained single occupants, whereas in unpolluted sites, the nesting traps collected from 4 to 5 species represented by up to ten individuals. Moreover, the proportion of dead individuals of the solitary bee Megachile ligniseca increased along the heavy metal pollution gradient at OLK from 0·2 in uncontaminated sites to 0·5 in sites with a high concentration of pollution. 5. Synthesis and applications. Our findings highlight the negative relationship between heavy metal pollution and populations of wild bees and suggest that increasing wild bee richness in highly contaminated areas will require special conservation strategies. These may include creating suitable nesting sites and sowing a mixture of flowering plants as well as installing artificial nests with wild bee cocoons in polluted areas. Applying protection plans to wild pollinating bee communities in heavy metal-contaminated areas will contribute to integrated land rehabilitation to minimize the impact of pollution on the environment.

The success of ectoparasites depends primarily on the site of attachment and body condition of their hosts. Ticks usually tend to aggregate on vertebrate hosts in specific areas, but the distribution pattern may depend on host body size and condition, sex, life stage or skin morphology. Here, we studied the distribution of ticks on lizards and tested the following hypothesis: occurrence or high abundance of ticks is confined with body parts with smaller scales and larger interscalar length because such sites should provide ticks with superior attachment conditions. This study was performed in field conditions in central Poland in 2008-2011. In total, 500 lizards (Lacerta agilis) were caught and 839 ticks (Ixodes ricinus, larvae and nymphs) were collected from them. Using generalised linear mixed models, we found that the ticks were most abundant on forelimbs and their axillae, with 90% of ticks attached there. This part of the lizard body and the region behind the hindlimb were covered by the smallest scales with relatively wide gaps between them. This does not fully support our hypothesis that ticks prefer locations with easy access to skin between scales, because it does not explain why so few ticks were in the hindlimb area. We found that the abundance of ticks was positively correlated with lizard body size index (snout-vent length). Tick abundance was also higher in male and mature lizards than in female and young individuals. Autotomy had no effect on tick abundance. We found no correlation between tick size and lizard morphology, sex, autotomy and body size index. The probability of occurrence of dead ticks was positively linked with the total number of ticks on the lizard but there was no relationship between dead tick presence and lizard size, sex or age. Thus lizard body size and sex are the major factors affecting the abundance of ticks, and these parasites are distributed nearly exclusively on the host's forelimbs and their axillae.

Background.One of the most difficult challenges for conservation biology is to reconcile growing human demands for resources with the rising need for protecting nature. Wind farms producing renewable energy have been recognised to be a threat for birds, but clear directives for environmental planning are still missing.Methods.Point counts were performed to study the relationship between eight environmental variables and bird populations in different parts of a year on the largest Polish wind farm between March 2011 and February 2013. Variables potentially related to species richness (Chao 1 estimator) and the abundance of the entire bird community as well as five selected farmland species were analysed with the use of generalized linear mixed models.Results.Some associations between the studied variables and bird populations were season/year specific, while others had a constant direction (positive or negative) across seasons and/or years. The latter were distance to the nearest turbine, field size, number of wind turbines, proximity of settlements and water bodies. Spatial autocorrelation and counting time were significantly correlated with bird population estimates but the directions of these relationships varied among seasons and years. Associations between abundance of individual species and environmental variables were species-specific.Conclusions.The results demonstrated a constant negative relationship between wind turbine proximity and bird numbers. Other environmental variables, such as field size, proximity of settlements and water bodies that also had constant associations with bird populations across seasons may be taken into account when minimizing adverse effects of wind farm development on birds or choosing optimal locations of new turbines.

Birds are commonly used as an example of the strongly declining farmland biodiversity in Europe. The populations of many species have been shown to suffer from intensification of management, reduction of landscape heterogeneity, and habitat loss and fragmentation. These conditions particularly dominate farmland in the economically well developed countries of Western Europe. Currently, the farmland environment in Central-Eastern Europe is generally more extensive than in Western Europe and a larger proportion of people still live in rural areas; thus generating different conditions for birds living in agricultural areas. Furthermore, the quasi-subsistence farming in much of Central-Eastern Europe has resulted in agricultural landscapes that are generally more complex than those in Western Europe. To protect declining bird populations living in farmland, detailed knowledge on both species and communities is necessary. However, due to scientific tradition and availability of funding, the majority of studies have been carried out in Western Europe. In consequence this provokes a question: are findings obtained in western conditions useful to identify the fate of farmland bird biodiversity in Central-Eastern Europe? Therefore, the major goal of this paper is to highlight some local and regional differences in biodiversity patterns within EU farmland by comparing intensive agricultural landscapes with more extensive ones. More specifically, we aim to outline differences in agricultural landscapes and land use history in the two regions, use farmland birds to provide examples of the differences in species dynamics and species-habitat interactions between the two regions, and discuss possible social and ecological drivers of the differences in the context of biodiversity conservation. Factors governing spatio-temporal dynamics of farmland bird populations may differ in intensive and extensive landscapes as illustrated here using the Grey Partridge Perdix perdix and the Red-backed Shrike Lanius collurio as examples. The unevenness of farmland bird studies distribution across Europe was also presented. We call for more emphasis on pluralism in furthering both pan-European research on farmland bird ecology and conservation strategies. We also highlight some features specific to Central-Eastern Europe that merit consideration for the more efficient conservation of farmland birds and farmland biodiversity across Europe.

Although shell colour polymorphism of the land snail Cepaea nemoralis is a well-known phenomenon, proximate and ultimate factors driving its evolution remain uncertain. Polymorphic species show variation in behavioural responses to selective forces. Therefore, we estimated effects of various environmental factors (temperature, humidity, food availability, (micro)habitat structure and predatory pressure) on behavioural response (frequency of locomotion, climbing and hiding) of C. nemoralis morphs, in experimental and natural conditions. In the experimental part of study, the frequency of locomotion was negatively affected by temperature and the presence of food and positively influenced by the presence of light. Morphs significantly differed in behavioural responses to environmental variability. Pink mid-banded and yellow five-banded morphs climbed less often and hide in shelter more often than yellow and pink unbanded individuals when temperature was low and food was absent. Snails fed most often at moderate temperature compared to low and high temperatures. Field investigations partially confirmed differences among morphs in frequency of climbing, but not in terms of probability of hiding in sheltered sites. In natural colonies, temperature and (micro)habitat structure significantly affected frequency of climbing as well as hiding in shelter. Snails more often hid in sheltered sites where thrushes preyed on Cepaea. Tendency of unbanded morphs to climb trees may have evolved under avian predatory pressure as thrushes forage on a ground. Tendency of banded morphs to hide in sheltered sites may reflect prey preferences for cryptic background. The results implicate that differential behaviour of C. nemoralis morphs compensate for their morphological and physiological limitations of adaptation to habitat. Electronic supplementary material The online version of this article (10.1007/s00114-018-1560-2) contains supplementary material, which is available to authorized users.