Birds like it Corky: the influence of habitat features and management of 'montados' in breeding bird communities.

In the southwest part of the Iberian Peninsula the dominant land-use are the Portuguese montados and Spanish dehesas, parkland forested areas of anthropogenic origin dominated by cork oak. They form a wooded matrix with open areas, scattered woodlands and undisturbed patches of Mediterranean forest and scrublands. The montados are characterized by a rich bird community. We have focus our study in a multidisciplinary approach, evaluating how management and landscape patterns influence the bird community in order to identify potential threats to its conservation. The study was conducted in the Site of Community Importance of Serra de Monfurado were 70% of the area is cork and holm oaks. We used data from 120 10-min point counts. Using variation partitioning, we determined the independent and joint effects of Forest, Management and Habitat variables. The variation captured in bird assemblage was 65.06%. Most of the explained variation was related to the Habitat and Management variables. The explanatory variables that were highlighted as important predictors were variables that reflected tree and shrub density and cork removal. Modelling for forest species through generalized linear models (GLM) emphasize that the management plays an important role in the species distribution. The most important variables selected in models reflected cattle grazing and cork removal. Our results point out that the type of management is crucial to maintain the equilibrium in bird community associated to montados. Farmland and forest species will benefit from areas with different tree densities, small patches of Mediterranean scrubs in the understory and correct livestock numbers

Exploring nest destruction and bird mortality in mown Mediterranean dry grasslands: an increasing threat to grassland bird conservation

In recent years, haying has extended to Iberian Mediterranean dry grasslands potentially impacting on grassland bird ecology. We evaluated the impact of haying on a grassland bird community of South Portugal. Our main goals were: (1) to investigate the exposure of different species to haying, (2) to investigate potential removal of nests and dead birds from hayed fields by haying machinery using the ratio (REC) between the expected number of records and the number of records collected and (3) to link clutch destruction and bird mortality with haying management practices. Hayed fields were surveyed for signs of breeding and birds censused prior to mowing. Linear models were computed, linking the REC with haying machinery and sward properties. GLMs and model averaging were used to obtain models linking clutch destruction, bird mortality and haying management variables. Only 4 % of records evidenced successful nesting attempts (N = 177). REC evaluation suggested high nest or dead bird removal by the machinery, particularly in fields with lower vegetation biomass prior to cutting. Sickle bar mowers and one-rotor rotary rakes returned higher REC but lower probability of found nests removed from the original nesting sites comparatively to discs mowers and wheel rakes. Higher probabilities of mortality events were found in fields mown earlier (but not in all years). On the other hand, lower mortality was found in fields raked with two-rotor rotary rakes. Delayed haying, silage production in temporary crops and the use haying machinery enabling simultaneously mowing and gathering hay in lines are discussed as management alternatives

Towards a legal definition of ecological restoration: Reviewing international, European and Member States' case law

Ecological restoration is of crucial importance to mitigate the impact of human activity on the environment and preserve biodiversity and ecosystem services. Therefore, the concept of restoration is at the core of international and European Union (EU) environmental policy and governance. This article seeks to shed light on this concept in international and European case law. To this end, it reviews the definition, objectives and scope of restoration according to international scientific standards. It further distinguishes restoration from other related terms such as compensation, mitigation, conservation and rehabilitation. The article then analyses judgements rendered by the International Court of Justice, the Court of Justice of the EU and EU Member States' courts pertaining to restoration. It concludes that there are wide discrepancies in the use of the term restoration by the judiciary, in particular with regard to objectives, baselines and reference conditions. In light of these conclusions, the authors support the adoption of a legal definition of restoration

Barn owl feathers as biomonitors of mercury: sources of variation in sampling procedures.

Given their central role in mercury (Hg) excretion and suitability as reservoirs, bird feathers are useful Hg biomonitors. Nevertheless, the interpretation of Hg concentrations is still questioned as a result of a poor knowledge of feather physiology and mechanisms affecting Hg deposition. Given the constraints of feather availability to ecotoxicological studies, we tested the effect of intra-individual differences in Hg concentrations according to feather type (body vs. flight feathers), position in the wing and size (mass and length) in order to understand how these factors could affect Hg estimates. We measured Hg concentration of 154 feathers from 28 un-moulted barn owls (Tyto alba), collected dead on roadsides. Median Hg concentration was 0.45 (0.076-4.5) mg kg(-1) in body feathers, 0.44 (0.040-4.9) mg kg(-1) in primary and 0.60 (0.042-4.7) mg kg(-1) in secondary feathers, and we found a poor effect of feather type on intra-individual Hg levels. We also found a negative effect of wing feather mass on Hg concentration but not of feather length and of its position in the wing. We hypothesize that differences in feather growth rate may be the main driver of between-feather differences in Hg concentrations, which can have implications in the interpretation of Hg concentrations in feathers. Finally, we recommend that, whenever possible, several feathers from the same individual should be analysed. The five innermost primaries have lowest mean deviations to both between-feather and intra-individual mean Hg concentration and thus should be selected under restrictive sampling scenarios

Progress in analytical approaches integrating Livestock and Biodiversity to identify HNV Montados

The World Congress Silvo-Pastoral Systems 2016 aims to gather researchers from different disciplines, practitioners and policy makers at different governance levels that deal with the management and sustainability of silvo-pastoral systems. In this way the congress will create a fertile context to progress through interdisciplinarity research approaches that can help translate scientific knowledge into new adaptive management solutions, and thus bridge from science to practice. The aim is also to gather and compare knowledge from silvo-pastoral systems around the world, which share drought as a limiting factor, so that they can be discussed and evaluated

Zonas Ribeirinhas Sustentáveis - um guia de gestão

The publication "Sustainable Riparian Zones. A Management Guide" is a compilation of themes related with the ecology, restoration and assessment of riparian zones. This guide is intended as a practical tool that will be very useful for managers and those professionally engaged in river and riverside conservation and/or restoration. This book aims to give the reader an overall view of what these natural systems are and how they function. This volume can be approached either in order of chapters or by singling out individual chapters as the reader's own interests and needs dictate. It attempts to address most of the main subjects and aspects that affect the integrity of riparian ecosystems, always trying to take a broad view that will be applicable to the vast majority of cases. Nevertheless, a marked Mediterranean tendency is evident, owing to the origin of most of the authors and to the context in which it arose. This book was produced and published under the RipiDurable project (www.ripidurable.eu), an INTERREG IIIC South Program partnership of 10 partners from Portugal, Spain, France and Greece aiming to contribute to improve the know-how and overcoming limitations in the development of management strategies for riparian zones, taking into account the natural features, the economic potential, and the importance of these habitats as ecological corridors. In this respect, the Project aims to contribute to the rehabilitation and/or restoration of these ecosystems

Superpredation patterns in four large Eupropean raptors

Predatory interactions among top predators, like superpredation or intraguild predation (IGP), can influence community structure. Diurnal raptors occupy high trophic levels in terrestrial food webs, and thus can regulate the presence of mesopredators. We studied superpredation (the killing and eating of another predator)in four large European raptors. We gathered 121 dietary studies, totalling 161,456 prey for the Goshawk Accipiter gentilis L., Golden Eagle Aquila chrysaetos L., Bonelli’s Eagle Aquila fasciata Vieillot, and Eagle Owl Bubo bubo L. Results showed that superpredation: (1) is a widespread interaction in large raptors, but it can vary according to the top predator species; (2) is not an important energetic resource for large raptors, but rather seems mostly related to diet diversification when the main prey decreases; (3) is spatially clustered reflecting habitat heterogeneity, but shows no temporal or large-scale spatial trends; and (4) it is associated with lower breeding success of the top predator species. These findings support the food stress hypothesis as the main driving force behind increases in superpredation and IGP in raptors, with the decrease in breeding performance as a side effect. Superpredation by large raptors deserves future research to understand its effects on mesopredators, because on one hand it might contribute to promote biodiversity, while on the other hand, it can sometimes represent an additional risk for small populations of endangered mesopredators

Superpredation increases mercury levels in a generalist top predator, the eagle owl

Superpredation can increase the length of the food chain and potentially lead to mercury (Hg) bioaccumulation in top predators. We analysed the relationship of Hg concentrations in eagle owls Bubo bubo to diet composition and the percentage of mesopredators in the diet. Hg levels were measured in the adult feathers of eagle owls from 33 owl territories in the south-western Iberian Peninsula, and in three trophic levels of their prey: primary consumers, secondary consumers and mesopredators. In addition, we studied 6,181 prey in the eagle owl diet. Hg concentrations increased along the food chain, but the concentrations in eagle owls showed considerable variation. The Hg concentration in eagle owls increased when the percentage of mesopredators in the diet increased and the percentage of primary consumers decreased. Superpredation is often related to food stress, and the associated increase in accumulation of Hg may cause additional negative effects on vertebrate top predators. Hg levels in these eagle owl populations are relatively low, but future monitoring is recommended

Kill fore being killed: an experimental approach supports the predator-removal hypothesis as a determinant of intraguild predation in top predators

Intraguild predation (IGP) has been explained in terms of competitor-removal, food-stress and predator removal hypotheses. Only the first two hypotheses have been fairly well studied. To test the predator-removal hypothesis as a force determining IGP in avian predators, we performed a field experiment to simulate the presence of an IG predator (eagle owl Bubo bubo dummy) in the surrounding of the nests of four potential IG prey (black kite Milvus migrans, red kite Milvus milvus, booted eagle Aquila pennata and common buzzard Buteo buteo). To discard the possibility that an aggressive reaction towards the eagle owl was not related to the presence of the IG predator, we also presented a stuffed tawny owl Strix aluco, which is a potential competitor but cannot be considered an IG predator of the studied diurnal raptors considered in the experiment. While almost always ignoring the tawny owl, raptors chiefly showed an interspecific aggressive behaviour towards their IG predator. Our results seem to support the predator-removal hypothesis, as the IG prey may take advantage of the diurnal inactivity of the IG predator to remove it from their territory. However, the recorded behaviour may be also considered as a special variety of mobbing (i.e. a prey’s counter-strategy against its predator), where the mobber is sufficiently powerful to escalate predator harassment into deliberate killing attempts. In their turn, eagle owls can respond with an IG predatory behaviour aimed at removing IG prey species which are highly aggressive mobbers

Situation of red-billed Leiothrix (Leiothrix lutea) in Europe and interactions with native species

During the last decades, the Asian-native red-billed leiothrix (Leiothrix lutea) has become established in Europe due to escapes or deliberate introductions. Despite a potential negative effect on ecosystems identified in other invaded regions, its situation in Europe and their potential effect on native birds are poorly known. We studied the behavioural and ecological relationships between leiothrix and the species composing the native bird community in central Portugal. We assessed which native species are more likely to compete for food (i.e., potential competitors) based on their structural size and diet composition (invertebrates and fruits). Our results showed that robin (Erithacus rubecula) and blackcap (Sylvia atricapilla) were the main potential competitors of leiothrix. We identified possible competitive advantages of leiothrix over its potential competitors considering its foraging morphology (e.g., a wider bill gape which promotes food swallowing). We also evaluated the role of behavioural dominance and aggressiveness on the establishment of leiothrix. We conducted a feeding experiment in a closed environment forcing dyadic interactions between a robin or a blackcap facing a leiothrix. We found that leiothrix were the initiators of the first interaction in most experiments, being apparently dominant over both native species.During the breeding season (spring), we used interactive playbacks to measure the behavioural response of blackcaps and robins (henceforth focal species) towards simulated intrusions by leiothrix. Leiothrix playbacks affected the singing behaviour of both focal species. Robins exhibited a longer latency to sing after leiothrix than after control playback. Both focal species avoided singing near the loudspeaker after leiothrix playback compared with control playback, which generally suggests a subordinate behaviour. Considering that our previous work indicated that leiothrix may displace some native species as result of its superior dominance, we decided to assess its distribution and population status in Europe. For that, we collected all public data available at citizen science databases and literature up to the end of 2017. We obtained records for 37 regions in 10 countries, and identified established populations in France, Italy, Spain, and Portugal. Its distribution range in Europe almost doubled in less than 20 years. A species distribution model showed that species presence probability increased with increasing combined values of human population density, spatial trend of occurrences, precipitation seasonality, precipitation of the driest quarter, and minimum temperature of the coldest month. Our results indicated high introduction rate near large urban areas resulting in a broad spread into adjacent forests. The establishment of leiothrix in natural habitats in Europe, and not in highly disturbed habitats as other invasive species, may constitute a new challenge for conservation