Flower visitation by birds in Europe

Most flowering plants depend on animal pollination. Several animal groups, including many birds, have specialized in exploiting floral nectar, while simultaneously pollinating the flowers they visit. These specialized pollinators are present in all continents except Europe and Antarctica, and thus, insects are often considered the only ecologically relevant pollinators in Europe. Nevertheless, generalist birds are also known to visit flowers, and several reports of flower visitation by birds in this continent prompted us to review available information in order to estimate its prevalence. We retrieved reports of flower–bird interactions from 62 publications. Forty‐six bird species visited the flowers of 95 plant species, 26 of these being exotic to Europe, yielding a total of 243 specific interactions. The ecological importance of bird–flower visitation in Europe is still unknown, particularly in terms of plant reproductive output, but effective pollination has been confirmed for several native and exotic plant species. We suggest nectar and pollen to be important food resources for several bird species, especially tits Cyanistes and Sylvia and Phylloscopus warblers during winter and spring. The prevalence of bird flower‐visitation, and thus potential bird pollination, is slightly more common in the Mediterranean basin, which is a stopover to many migrant bird species, which might actually increase their effectiveness as pollinators by promoting long‐distance pollen flow. We argue that research on bird pollination in Europe deserves further attention to explore its ecological and evolutionary relevance.     

The conservation of declining butterfly populations in Britain and Europe: priorities, problems and successes

The status, ecology and conservation of butterflies in Europe and Britain are reviewed, as a background to the National Trust's past and future contribution to British conservation. Britain has a poor butterfly fauna by European standards, the main areas of endemism and species richness being in the Alps and southern Europe. To date, the main declines among European butterfly populations have occurred across central-northern Europe, with slightly higher extinction rates in mainland countries than in Britain. The main causes of decline are biotope destruction, the loss of certain species' habitats within surviving semi-natural biotopes due to changed land management, and a failure by several species to track the patches of their habitat that are still being generated in modern fragmented landscapes. Until recently, most conservation programmes failed to take account of the latter two factors, resulting in many local extinctions of rare butterfly species even in conservation areas. Recent measures have been much more successful; many were first tested on National Trust properties.     

Scale-dependent diversity effects of seed dispersal by a wild herbivore in fragmented grasslands

Dispersal limitation between habitat fragments is a known driver of landscape-scale biodiversity loss. In Europe, agricultural intensification during the twentieth century resulted in losses of both grassland habitat and traditional grassland seed dispersal vectors such as livestock. During the same period, populations of large wild herbivores have increased in the landscape. Usually studied in woodland ecosystems, these animals are found to disperse seeds from grasslands and other open habitats. We studied endozoochorous seed dispersal by roe deer (Capreolus capreolus) in fragmented grasslands and grassland remnants, comparing dispersed subcommunities of plant species to those in the established vegetation and the seed bank. A total of 652 seedlings of 67 species emerged from 219 samples of roe deer dung. This included many grassland species, and several local grassland specialists. Dispersal had potentially different effects on diversity at different spatial scales. Almost all sites received seeds of species not observed in the vegetation or seed bank at that site, suggesting that local diversity might not be dispersal limited. This pattern was less evident at the landscape scale, where fewer new species were introduced. Nonetheless, long-distance dispersal by large wild herbivores might still provide connectivity between fragmented habitats within a landscape in the areas in which they are active. Finally, as only a subset of the available species were found to disperse in space as well as time, the danger of future biodiversity loss might still exist in many isolated grassland habitats.     

When morphological identification meets genetic data: the case of Lucanus cervus and L. tetraodon (Coleoptera,Lucanidae)

The European stag beetle Lucanus cervus, widely distributed across Europe and in some Near East countries, is one of the best known coleopteran species listed in the European Habitats Directive 92/43/EEC and it is considered a flagship species for conservation of saproxylic fauna. Lucanus tetraodon is a closely related species whose geographical distribution is still poorly known and debated. The two species have a sympatric occurrence in central Italy, and in some localities of these areas, many individuals show a mosaic of morphological traits that makes species assignment nearly impossible. We used both mitochondrial and nuclear markers to analyse these specimens. The mitochondrial results evidenced that the two species represent well‐defined genetic entities with mitochondrial DNA introgression. This pattern could be the result of either hybridization or of a convergence of morphological characters under local selective pressures in areas of sympatric occurrence. The nuclear marker was polymorphic across the two species and therefore did not reveal hybridization, even if many are the supports to this phenomenon. The most plausible explanation for this genetic pattern is a very recent divergence of the two species which share a common origin and thus a common wg genotype.     

International cooperation on western corn rootworm ecology research: state-of-the-art and future research

1 Invasive pest species are challenging partly because the invasion process may be highly dynamic and because of the lack of knowledge of many researchers, professionals and farmers in the newly-invaded regions. The chrysomelid Diabrotica virgifera virgifera LeConte is such an invasive pest. It has been the main pest of continuous maize in the U.S.A. for more than 60 years and is currently spreading throughout Europe.
2 In the area with a long history of this pest (Central and North America), scientific knowledge concerning the ecology of this pest has accumulated over the last decades. This resource is of great importance to both America and Europe and has to be gathered, shared and adapted to new situations. We therefore examined, both qualitatively and quantitatively, the scientific literature relating to D.   virgifera virgifera ecology.
3 The quantitative analysis suggests that research on D.   virgifera virgifera ecology is still in its infancy in Europe and suffers from geographical barriers (between Europe and North America and between linguistic areas within Europe) and that scientific communication should be strengthened both between North America and Europe and within Europe.
4 As a first solution to this problem, we introduce three companion review articles that constitute a landmark for D.   virgifera virgifera research, enabling European and American scientists and decision-makers to orient themselves and discover new opportunities for research. We also stress that international research cooperation is the most important key to successfully manage invasive species.     

Kragge-woodlands in the Netherlands as a new community-type within the Alnion glutinosae

In the low-lying parts of The Netherlands peat-cutting in the past resulted in many large and small lakes. The larger ones were often reclaimed and turned into arable land. In smaller ones a process of secondary succession led to the establishment of reed and sedge fens. Due to changes in the management many of the still existing fens have been left over to natural developments over the last decades. Here succession rapidly led to woodland communities. These woodlands are initially often dominated by Salix species, soon followed by Alnus glutinosa and Betula pubescens. In species composition these young woodlands are closely related to the Carici elongatae-Alnetum glutinosae. There are, however, considerable differences in species composition. This woodland type as found in the western parts of The Netherlands was also recognized in relevés from Belgium, western Germany and Norfolk in the UK. As it also differs in ecological conditions from the brooks and rivulets accompanying forms of the Alnion glutinosae elsewhere in western Europe, it is here proposed to treat these communities as a separate community-type within the Alnion glutinosae.     

Eurycercus glacialis in Ireland (Cladocera,Chydoridae)

The taxon Eurycercus glacialis of Western Europe has been discovered living in the turloughs (tuar loch = dry lake) of Western Ireland. Only four populations were found during three field excursions, but because of the multitude of these waterbodies in the region, there must be many populations present. Turloughs are mainly periodic waterbodies occupying depressions in the drift overlying limestone. Most of them dry every year, and the bottoms are then used for grazing cattle. This periodicity prevents the establishment of fish populations, which would rapidly eliminate the cladoceran by size-selective predation. Only one of the many populations known from Western Europe survives in the presence of fishes. A species of the glacialis group in Newfoundland (not yet described), which is the southernmost known location of E. glacialis sens. lat. in the world, occurs commonly with salmonid or gasterosteid fishes, but this is a completely different species. Scanning electron micrographs of E. glacialis and E. lamellatus in Western Europe will aid in understanding their morphological differences.     

Use of multiple markers demonstrates a cryptic western refugium and postglacial colonisation routes of Atlantic salmon (Salmo salar L.) in northwest Europe

Glacial and postglacial processes are known to be important determinants of contemporary population structuring for many species. In Europe, refugia in the Italian, Balkan and Iberian peninsulas are believed to be the main sources of species colonising northern Europe after the glacial retreat; however, there is increasing evidence of small, cryptic refugia existing north of these for many cold-tolerant species. This study examined the glacial history of Atlantic salmon in western Europe using two independent classes of molecular markers, microsatellites (nuclear) and mitochondrial DNA variation. Alongside the well-documented refuge in the Iberian Peninsula, evidence for a cryptic refuge in northwest France is also presented. Critically, methods utilised to estimate divergence times between the refugia indicated that salmon in these two regions had diverged a long time before the last glacial maximum; coalescence analysis (as implemented in the program IMa2) estimated divergence times at around 60 000 years before present. Through the examination of haplotype frequencies, previously glaciated areas of northwest Europe, that is, Britain and Ireland, appear to have been colonised from salmon expanding out of both refugia, with the southwest of England being the primary contact zone and exhibiting the highest genetic diversity.     

Climate patterns and the stochastic dynamics of migratory birds

We analyse time series data of 17 bird species trapped at Ottenby Bird Observatory, Sweden, during spring migration 1972–1999. The species have similar demography but respond differently to variation in the North Atlantic Oscillation (NAO) – a strong determinant of winter climate in the northern Hemisphere. Species wintering in northern Europe, compared to species having winter quarters in the Mediterranean area, tend to respond positively to variation in NAO. The variation within each group is high due to wide-ranging winter-distribution in many species, probably smoothing out the effect of spatial variation in NAO. Whereas mild winters (high NAO) is benign for many – but not all – birds wintering in northern Europe, the effect of drier-than-normal conditions in the Mediterranean area during high NAO index winters are uncertain. The work presented here goes beyond simple correlative studies and help identifying which species that are most affected by variation in winter climate. This is a first important step that calls for a more mechanistic approach when analysing possible changes to climate change.     

Mamulichthys ignotus gen. et sp. nov., a new actinopterygian from the Middle Permian of the southeastern East Europe Platform

A new actinopterygian genus and species of the family Discordichthyidae, Mamulichthys ignotus gen. et sp. nov., from the upper part of the Urzhumian Stage of the Middle Permian of the southeastern East Europe Platform is described. The fish has a large rounded operculum and dorsal and pectoral fin spines. The side scales are high. The abdomen has longitudinal rows of large, massive, strongly overlapping falciform scales. All dermal bones are ornamented with many hollow tubercles varying in shape and size. At present, representatives of Discordichthyidae are only known from Eastern Europe.     

A checklist of British and Irish freshwater fish parasites with notes on their distribution

One hundred and sixty eight species of parasite are listed from 36 species of freshwater fish from Britain and Ireland, and notes on their distribution are provided. A list of hosts together with the parasites recorded from them is also given. Although almost twice as many species are listed as in the most recent published reference list, the parasite fauna of Britain appears to be considerably poorer in number of species than that of mainland Europe, and that of Ireland poorer still. The distribution of most species, apart from two endemic species and a very few which have clearly been introduced into Britain in recent years from America or the mainland of Europe, appears to show no peculiarities and is probably contiguous with that of their hosts.     

The status of the otter (Lutra lutra) in the British Isles

National field surveys for otters were carried out between 1977 and 1981. The species is apparently absent from large areas of England, although healthy populations still occur in the south-west. In many other areas, populations are isolated and fragmented and there is some evidence for continuing declines. In Wales the otter is rare or absent from the south and parts of the north. Healthy populations are present in the Highland Region of Scotland, on the north and west coasts and in the islands but there is evidence of a decline in the south and east-central lowlands. Otters are widespread and common in Ireland which sustains the best of the known populations in Europe.
Pollution by pesticides probably caused the initial rapid decline of the species but habitat destruction is increasingly important and where habitat is poor, human disturbance assumes greater significance. There is no evidence of competition with mink. The otter is now a protected species but if it is to recover some of its former range, remaining habitat must be retained.
While otter populations have decreased over much of northern Europe, the animal survives, albeit somewhat precariously, in a few southern parts of the continent.     

Regional and local patterns in plant species richness with respect to resource availability

The hump-shaped relationship between plant species richness and productivity is a well-established and important paradigm. While plot-based species richness patterns on local scales have received much attention, little is currently known about species-based patterns on a regional scale. Using Ellenberg's indicator values for 1802 plant species in central Europe, we assess the patterns in regional species richness with respect to light, water, and mineral nutrient availability – three variables that strongly influence productivity. The results of this analysis are compared to those of published studies on smaller scales leading to the following conclusions:

• 1.

  On a regional scale in central Europe there is a hump-shaped relationship between soil nutrient supply and plant species richness within a given biome.

       
  
  

Tracing the radiation of Maniola (Nymphalidae) butterflies: new insights from phylogeography hint at one single incompletely differentiated species complex

The use of DNA sequence data often leads to the recognition of cryptic species within putatively well‐known taxa. The opposite case, detecting less diversity than originally described, has, however, far more rarely been documented. Maniola jurtina, the Meadow Brown butterfly, occurs all over Europe, whereas all other six species in the genus Maniola are restricted to the Mediterranean area. Among them, three are island endemics on Sardinia, Cyprus, and Chios, respectively. Maniola species are almost indistinguishable morphologically, and hybridization seems to occur occasionally. To clarify species boundaries and diversification history of the genus, we reconstructed the phylogeography and phylogeny of all seven species within Maniola analyzing 138 individuals from across its range using mitochondrial and nuclear genetic markers. Examination of variation in mitochondrial and nuclear DNA surprisingly revealed a case of taxonomic “oversplitting”. The topology of the recovered phylogenetic tree is not consistent with accepted taxonomy, but rather reveals haplotype clades that are incongruent with nominal species boundaries: instead of seven species, we recognized only two major, yet incompletely segregated, lineages. Our results are consistent with the hypothesis that Maniola originated in Africa. We suggest that one lineage dispersed over the Strait of Gibraltar and the Iberian Peninsula to the west of Europe, while the other lineage spreads eastward through Asia Minor and over the Bosporus to Eastern Europe.     

Phylogeny, classification and taxonomy of European dragonflies and damselflies (Odonata): a review

Although Europe is the cradle of dragonfly systematics and despite great progress in the last 2 decades, many issues in naming its species and understanding their evolutionary history remain unresolved. Given the public interest, conservation importance and scientific relevance of Odonata, it is time that remaining questions on the species?? status, names and affinities are settled. We review the extensive but fragmentary literature on the phylogeny, classification and taxonomy of European Odonata, providing summary phylogenies for well-studied groups and an ecological, biogeographic and evolutionary context where possible. Priorities for further taxonomic, phylogenetic and biogeographic research are listed and discussed. We predict that within a decade the phylogeny of all European species will be known.     

Poor water quality constrains the distribution and movements of twaite shad <Emphasis Type="Italic">Alosa fallax</Emphasis><Emphasis Type="Italic">fallax</Emphasis> (Lacépède, 1803) in the watershed of river Scheldt

Worldwide, river fragmentation is primarily responsible for the decline of populations of migrating fish. In particular, anadromous fish species, which necessarily migrate to fresh water to reproduce, are endangered since many are no longer able to reach their natural spawning sites. In addition, pollution of rivers effectively prevents upstream or downstream movements and blocks access to spawning grounds. This article investigates how poor water quality interferes with the life history cycle of twaite shad Alosa fallax fallax (Lacépède, 1803), an anadromous clupeid fish, in the watershed of River Scheldt, a heavily impacted environment in West Europe. We used two models based on known ecological and environmental information to explain past and present twaite shad distribution within the watershed and to make inferences about a future population recovery and juvenile habitat value. We demonstrated that historical spawning areas satisfy water quality conditions necessary to support spawning and successful development of early life history stages of the twaite shad. However, poor water quality conditions just upstream the freshwater–saltwater boundary still act as an effective migration barrier for upstream movement. As a consequence, spawning grounds are inaccessible and the population is dominated by seasonal adults occurring in the lower estuarine part of the watershed. This article provides testable and diagnostic information to the watershed management in that it identifies habitat and water quality requirements needed to support the expected recovery of an endangered anadromous fish population. Guest editors: S. Dufour, E. Prévost, E. Rochard & P. Williot Fish and diadromy in Europe (ecology, management, conservation)     

DNA sequence analyses reveal abundant diversity, endemism and evidence for Asian origin of the porcini mushrooms

The wild gourmet mushroom Boletus edulis and its close allies are of significant ecological and economic importance. They are found throughout the Northern Hemisphere, but despite their ubiquity there are still many unresolved issues with regard to the taxonomy, systematics and biogeography of this group of mushrooms. Most phylogenetic studies of Boletus so far have characterized samples from North America and Europe and little information is available on samples from other areas, including the ecologically and geographically diverse regions of China. Here we analyzed DNA sequence variation in three gene markers from samples of these mushrooms from across China and compared our findings with those from other representative regions. Our results revealed fifteen novel phylogenetic species (about one-third of the known species) and a newly identified lineage represented by Boletus sp. HKAS71346 from tropical Asia. The phylogenetic analyses support eastern Asia as the center of diversity for the porcini sensu stricto clade. Within this clade, B. edulis is the only known holarctic species. The majority of the other phylogenetic species are geographically restricted in their distributions. Furthermore, molecular dating and geological evidence suggest that this group of mushrooms originated during the Eocene in eastern Asia, followed by dispersal to and subsequent speciation in other parts of Asia, Europe, and the Americas from the middle Miocene through the early Pliocene. In contrast to the ancient dispersal of porcini in the strict sense in the Northern Hemisphere, the occurrence of B. reticulatus and B. edulis sensu lato in the Southern Hemisphere was probably due to recent human-mediated introductions.     

Threat of non-native crayfish introductions into Turkey: global lessons

Introductions of crayfish species from their home range to new environments have been carried out in many parts of the world. The most important introduced crayfish species are Procambarus clarkii, Pacifastacus leniusculus, Cherax destructor, C. quadricarinatus, Orconectes limosus, O. rusticus and Astacus leptodactylus. The environmental impact of crayfish introductions can be positive, negative or neutral. However, native crayfish populations in Europe have been negatively affected by introductions of non-indigenous crayfish species from America. Negative effects of non-native crayfish introductions included displacement of native crayfish species, transfer of disease (crayfish plague), consumption of fish eggs, reduction of fish stocks, consumption of large amounts of macrophytes, indirect and direct effects on other invertebrates and upsetting production in rice fields. As a result of non-native crayfish introductions, the natural harvest and crayfish industry in Europe have been severely affected. Large quantities of Turkish A. leptodactylus were harvested (approximately 7,000 tonnes annually) and exported to Europe before the crayfish plague was observed in these populations. The total harvest of A. leptodactylus in Turkey reduced dramatically to 320 in 1991 after the plague. Therefore, although Turkey currently has no known non-native crayfish species, there is a threat of non-native crayfish introduction in order to increase crayfish productions and subsequent harvest. The North American spiny-cheek crayfish, O. limosus, has been spreading quickly down the River Danube and could soon reach neighboring countries including Turkey. The North American signal crayfish, P. leniusculus is known from Greece and could be a threat to native stocks if it is introduced into Turkey for aquaculture. Additional threats may come from the release of other North American species, which are widely available through the aquarium trade. We conclude that the spread of non-native crayfish introductions throughout Turkey will increase local problems, because introductions of non-native crayfish in many parts of the world have been known to have caused important reductions in population density and numbers of native crayfish species. Furthermore, freshwater ecosystems may be altered by such introductions and the economic viability of native crayfish species fisheries could be severely reduced in Turkey.     

Nature versus nurture? Consequences of short captivity in early stages

Biological changes occurring as a consequence of domestication and/or captivity are not still deeply known. In Atlantic salmon (Salmo salar), endangered (Southern Europe) populations are enhanced by supportive breeding, which involves only 6 months of captive rearing following artificial spawning of wild‐collected adults. In this work, we assess whether several fitness‐correlated life‐history traits (migratory behavior, straying rate, age at maturity, and growth) are affected by early exposure to the captive environment within a generation, before reproduction thus before genetic selection. Results showed significant differences in growth and migratory behavior (including straying), associated with this very short period of captivity in natural fish populations, changing even genetic variability (decreased in hatchery‐reared adults) and the native population structure within and between rivers of the species. These changes appeared within a single generation, suggesting very short time of captivity is enough for initiating changes normally attributed to domestication. These results may have potential implications for the long‐term population stability/viability of species subjected to restoration and enhancement processes and could be also considered for the management of zoo populations.     

Emerging rickettsioses

Ticks are known to carry and transmit a number of microbial agents that cause diseases in humans and animals. Among these are members of the order Rickettsiales (alpha-proteobacteria), which include the genera Rickettsia and Ehrlichia. The most common and well-known Rickettsial human disease in Europe is Mediterranean Spotted Fever (MSF), caused by Rickettsia conorii. In recent years, a number of new Rickettsia species have been discovered in Europe, some of which have been shown to be pathogenic to humans. These discoveries have been facilitated by use of sequence-based molecular identification techniques. In Italy, it is generally believed that R. conorii is the only Rickettsia species present, and clinical tests for MSF rely on antigens raised against this bacterium. We are currently undertaking a molecular screening study of Rickettsiales-bacteria in ticks from various regions of Italy, to check for the potential presence of species from this order recently discovered in other parts of Europe. So far, we have identified a number of additional species in ticks collected from northern, central and southern regions. These include the known pathogens R. helvetica and R. slovaca as well as two species which may or may not be of medical relevance: R. monacensis and R. sp. IRS4. As a part of this survey, we have identified a novel alphaproteobacterium from the medically important tick Ixodes ricinus. This bacterium, tentatively named IricES1, has the unusual property of existing within the mitochondria, as well as the cytoplasm, of ovarian cells. To our knowledge, this is the only known example of a bacterium that is able to enter the mitochondria of animals. Our recently published electron microscopic data indicates that the bacterium enters mitochondria between the inner and outer membranes, and then proceeds to consume the inner mitochondrial matrix. We will present further data on this bacterium, including: 1) its phylogenetic position based on various molecular sequences, 2) its localization within the tick based on in situ hybridization; 3) its distribution among tick populations in Europe; 4) preliminary data on attempts at culturing this bacterium in a variety of cell types. Possible interactions between the bacterium and its host will be discussed. Ticks are known to carry and transmit a number of microbial agents that cause diseases in humans and animals. Among these are members of the order Rickettsiales (alpha-proteobacteria), which include the genera Rickettsia and Ehrlichia. The most common and well-known Rickettsial human disease in Europe is Mediterranean Spotted Fever (MSF), caused by Rickettsia conorii. In recent years, a number of new Rickettsia species have been discovered in Europe, some of which have been shown to be pathogenic to humans. These discoveries have been facilitated by use of sequence-based molecular identification techniques. In Italy, it is generally believed that R. conorii is the only Rickettsia species present, and clinical tests for MSF rely on antigens raised against this bacterium. We are currently undertaking a molecular screening study of Rickettsiales-bacteria in ticks from various regions of Italy, to check for the potential presence of species from this order recently discovered in other parts of Europe. So far, we have identified a number of additional species in ticks collected from northern, central and southern regions. These include the known pathogens R. helvetica and R. slovaca as well as two species which may or may not be of medical relevance: R. monacensis and R. sp. IRS4. As a part of this survey, we have identified a novel alphaproteobacterium from the medically important tick Ixodes ricinus. This bacterium, tentatively named IricES1, has the unusual property of existing within the mitochondria, as well as the cytoplasm, of ovarian cells. To our knowledge, this is the only known example of a bacterium that is able to enter the mitochondria of animals. Our recently published electron microscopic data indicates that the bacterium enters mitochondria between the inner and outer membranes, and then proceeds to consume the inner mitochondrial matrix. We will present further data on this bacterium, including: 1) its phylogenetic position based on various molecular sequences, 2) its localization within the tick based on in situ hybridization; 3) its distribution among tick populations in Europe; 4) preliminary data on attempts at culturing this bacterium in a variety of cell types. Possible interactions between the bacterium and its host will be discussed.