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Wind energy facilities (WEFs) are a relatively novel impact on wildlife habitats, and an increasing number of studies show negative effects on wildlife. Increased stress‐associated hormone levels are an indicator of disturbance effects, and measuring fecal glucocorticoid metabolite (FCM) levels is an established noninvasive method to study disturbance effects on wildlife. We studied whether FCM levels of capercaillie (Tetrao urogallus), a locally threatened forest bird species with proven behavioral responses to WEF, are affected by WEF. Using a before–after–control–impact (BACI) study design at sites in Austria, Germany and Sweden we investigated whether mean FCM levels changed after the construction of WEF and whether there was spatial variation in FCM levels in relation to WEF impacts. By analyzing 553 fecal samples from five wind farms and five control sites, we did not find evidence of increased FCM levels due to WEF when comparing wind farm sites before and after WEF construction with control sites. We further could not detect any spatial variation in FCM levels at wind farms related to turbine effects. There was, however, temporal variation in FCM, with lower FCM levels toward the end of the winter season. Differences among individual study sites emphasize the importance of larger studies with a BACI study design. Facing some methodological limitations, we currently find no evidence for an increase in FCM levels in capercaillie due to WEF., We studied whether stress levels of capercaillie (Tetrao urogallus) are affected by wind turbines in three biogeographical regions in Europe. No evidence was found of increased stress levels due to wind turbines.

Genetic differentiation plays an essential role in the assessment of metapopulation systems of conservation concern. Migration rates affect the degree of genetic differentiation between subpopulations, with increasing genetic differentiation leading to increasing extinction risk. Analyses of genetic differentiation repeated over time together with projections into the future are therefore important to inform conservation. We investigated genetic differentiation in a closed metapopulation system of an obligate forest grouse, the Western capercaillie Tetrao urogallus, by comparing microsatellite population structure between a historic and a recent time period. We found an increase in genetic differentiation over a period of approximately 15 years. Making use of forward simulations accounting for population dynamics and genetics from both time periods, we explored future genetic differentiation by implementing scenarios of differing migration rates. Using migration rates derived from the recent dataset, simulations predicted further increase of genetic differentiation by 2050. We then examined effects of two realistic yet hypothetical migration scenarios on genetic differentiation. While isolation of a subpopulation led to overall increased genetic differentiation, the re-establishment of connectivity between two subpopulations maintained genetic differentiation at recent levels. Our results emphasize the importance of maintaining connectivity between subpopulations in order to prevent further genetic differentiation and loss of genetic variation. The simulation set-up we developed is highly adaptable and will aid researchers and conservationists alike in anticipating consequences of conservation strategies for metapopulation systems.

Open forest stands with high levels of sunlight and Bilberry Vaccinium myrtillus cover are important for Capercaillie Tetrao urogallus broods.To study the habitat use by Capercaillie broods in the ...

There is increasing concern about the impact of the current boom in wind energy facilities (WEF) and associated infrastructure on wildlife. However, the direct and indirect effects of these facilities on the mortality, occurrence and behaviour of rare and threatened species are poorly understood. We conducted a literature review to examine the potential impacts of WEF on grouse species. We studied whether grouse (1) collide with wind turbines, (2) show behavioural responses in relation to wind turbine developments, and (3) if there are documented effects of WEF on their population sizes or dynamics. Our review is based on 35 sources, including peer-reviewed articles as well as grey literature. Effects of wind turbine facilities on grouse have been studied for eight species. Five grouse species have been found to collide with wind turbines, in particular with the towers. Fifteen studies reported behavioural responses in relation to wind turbine facilities in grouse (seven species), including spatial avoidance, displacement of lekking or nesting sites, or the time invested in breeding vs. non-breeding behaviour. Grouse were affected at up to distances of 500 m by WEF infrastructure, with indications of effects also at bigger distances. In six cases, a local reduction in grouse abundance was reported in areas with wind turbines, which possibly affected population size. Due to the differences in study duration and design, we cannot provide general conclusions on the effects of WEF on grouse populations. We advise applying the precautionary principle by keeping grouse habitats free of wind energy developments, in particular where populations are small or locally threatened. Future studies should preferably apply a long-term before-after-control-impact design for multiple areas to allow for more general conclusions to be drawn on the effects of WEF on rare and threatened wildlife species.

Outdoor recreation activities are growing in popularity, causing increasing pressure on wildlife. There are various ways in which wildlife reacts to recreation activities, ranging from behavioural to physiological responses, with regional variation in response-intensity within the same species. We tested whether the effects of human recreation are modulated by overall structural habitat suitability, using a model that included vegetation and topography, at both the regional and local habitat use scale. By undertaking a systematic, plot-based survey over 13 years in 13 study regions across central Europe, we studied how recreation infrastructure and habitat suitability interact and affect the variation in regional densities and local habitat use of an endangered model species: the western capercaillie (Tetrao urogallus). Both regional densities and local habitat use varied greatly between study years and regions. Capercaillie densities were positively correlated with average habitat suitability, but significantly reduced when over 50% of the area was influenced by recreation activities. Habitat suitability was the main predictor determining local habitat use. Recreation infrastructures were avoided: the effect being stronger in poor habitat conditions, while slightly mediated by high habitat suitability. Our results indicate that effects of recreation activities might be mitigated by improving habitat suitability; however this has limits because it only affects local scale habitat use but not regional densities. We stress the importance of recreation-free areas which must cover extensive (i.e. >50%) parts of the species range.

1. As a non‐invasive and inexpensive method, the use of faecal glucocorticoid metabolites (FGM) analysis in wildlife research is increasing. Various environmental factors have been shown to influence FGM levels, or faecal corticosteroid metabolites (FCM) levels in birds, but most studies do not account for inter‐individual variance, which we hypothesized may substantially affect results. 2. We combined FCM analysis with genetic analysis to identify the sex and individual's identity in samples collected in three consecutive winters; with repeated samples per individual, across the entire range of an endangered population of capercaillie Tetrao urogallus in south‐western Germany. Using generalized additive mixed models, we modelled FCM levels as a function of sex, season and environmental covariates at two spatial scales: location and home range. We compared two models: one including information on the individual animal and the other excluding this information (i.e. naive model) to assess the influence of individual heterogeneity on the results obtained. 3. Models accounting for inter‐individual differences explained 44.0% and 45.1% (at the location and home‐range scale respectively), while only very little (4.0% and 5.1%, respectively) was explained by the environmental predictors. When ignoring individual effects, the model results changed considerably with other, previously non‐informative predictors, becoming significant. 4. In the full models, accounting for inter‐individual variance, weather conditions had no effect at either scale. FCM levels were negatively correlated with habitat quality at the sampling location, while human recreation at the home‐range scale led to elevated FCM levels. In the naive models, two additional predictors appeared significant: one weather variable at the local scales and two at the home‐range scale. In all models, seasonal FCM patterns differed significantly between males and females. 5. Synthesis and applications. By combining faecal corticosteroid metabolites (FCM) analysis with genetic individual assessment, we demonstrate that individual heterogeneity can explain most of the variance in faecal corticosteroid metabolites levels and that ignoring this information can lead to erroneous conclusions when testing for environmental stressors. We therefore stress the importance of identifying individuals when studying faecal corticosteroid metabolites in wildlife and recommend combining faecal corticosteroid metabolites analyses with genetic analyses to adequately address this issue.

Primary forests are characterized by high vertical and horizontal stand diversity, which provides habitat for a diverse range of species with complex habitat requirements. Detailed knowledge of related ecological processes and habitat development of primary forest species are essential to inform forest management and biodiversity conservation decisions, but relationships are not well documented. We collected dendrochronological data and inventoried numerous structural elements in permanent plots throughout the primary temperate forests within the Carpathian Mountains. We fit and compared multiple predictive models to quantify the importance of 200 years of natural disturbance dynamics on the occurrence probability of an umbrella species – the capercaillie (Tetrao urogallus). We showed that a mixed-severity disturbance regime ranging from low through moderate to high severity disturbances is required to generate diverse forest habitats suitable for capercaillie. The variation in natural disturbance severity and its timing promoted key structural habitat elements, such as low natural regeneration density, low mature tree density, high ground vegetation cover, availability of forest gaps, and abundance of standing deadwood. This study demonstrates the importance of natural disturbance in maintaining the variety of conditions necessary to support primary forest specialist species. Managers of protected areas should be mindful that natural disturbances generate habitat for the capercaillie in mountain Norway spruce forests. Further intervention is unnecessary. Conservation planning and forest reserve design should shift focus to the large-scale spatial requirements needed to ensure that a wide range of forest developmental phases are represented in protected areas.

Outdoor recreation inflicts a wide array of impacts on individual animals, many of them reflected in the avoidance of disturbed areas. The scale and spatial extent, however, at which wildlife populations are affected, are mostly unclear. Particularly in geographically isolated populations, where restricted habitat availability may preclude a relocation to undisturbed areas, effective habitat reduction may remain underestimated or even unnoticed, when animals stay in disturbed areas and only show small-scale responses. Based on telemetry data, we investigated the spatial and seasonal effects of outdoor recreation - in relation to landscape and vegetation conditions – on western capercaillie Tetrao urogallus, considering two scales, homerange and within-homerange habitat selection. We determined the distance-thresholds up to which recreation infrastructures were avoided and estimated the extent of affected habitat for the isolated Black Forest (Southwestern Germany) study population. While outdoor recreation did not affect homerange selection, strong effects on habitat use within the homerange were detected: Distance to recreation infrastructure (hiking and cross-country skiing trails, ski pistes) was the main determinant of habitat selection in winter; in summer, mountain bike trails and hiker's restaurants were avoided up to an average distance of 145m (CI: 60-1092m). Around winter-infrastructure, relative avoidance was recorded up to 320m (CI: 36-327m), it was reduced, however, when dense understory provided visual cover. Of the entire population area, between 8- 20% (summer) and 8- 40% (winter) were affected by outdoor recreation, mainly in the high altitudes. Even without evident large-scale shifts in species distribution, local-scale avoidance of outdoor recreation can substantially contribute to effective habitat reduction. Based on our results we recommend a general reduction in recreation infrastructure density in key habitats, the establishment of undisturbed wildlife refuges with a diameter of at least 800m, as well as enhancing visual protection by maintaining a strip of dense understory along trails. This article is protected by copyright. All rights reserved.

The degradation of forest habitats in managed forests is a major threat to biodiversity. Accordingly, the conservation of forest-dwelling species has to be integrated with other goals and paradigms of production forestry. As those objectives may differ, it is crucial to quantify the potential effectiveness of habitat management for conservation to demonstrate its actual value. Here, we analysed detailed field-based distribution maps of a declining population of capercaillie (Tetrao urogallus), an indicator of open, structurally diverse conifer-dominated forests, in southwestern Germany to quantify the potential effect size of habitat management. We modelled range loss dynamics as a function of habitat structures obtained from high-resolution aerial stereo imagery, in order to estimate the potential increase in the probability of local capercaillie persistence under different management scenarios. Furthermore we identified situations in which habitat management would produce the largest conservation benefits. The probability of local capercaillie persistence during the study period was positively related to population connectivity, winter snow height and the availability of suitable forest structures. The positive effect of habitat management was largest at sites where persistence probability would otherwise be low to intermediate. Potential negative effects of decreasing snow load under climate change on local capercaillie persistence could be compensated more effectively by habitat improvement than a lack of population connectivity, implying that focusing habitat management on the edges of the distribution in addition to core areas would maximize conservation returns. Our results may thus contribute to an effective allocation of conservation investments where their leverage is highest.

There are growing concerns about the effects of wind turbines on wildlife. Additional mortality due to collisions with wind turbines has long been recognized as a direct negative effect, but less obvious effects such as changes in behaviour or displacement of disturbance sensitive wildlife are increasingly moving into focus. We combined systematic mapping of habitat structure and species presence before and after turbine-construction at 6 study areas in Germany, Austria and Sweden to study the effects of wind turbine presence on a large forest grouse species: the capercaillie (Tetrao urogallus). We studied effects of wind turbines on the observation density (percent of sampling plots with capercaillie presence per year and study area) and habitat selection. We did not find a significant difference in overall observation densities between turbine and control areas after turbine construction. At the sampling-plot scale, however, selection of habitats affected by wind turbines was reduced, indicating a form of habitat deterioration. This was detectable up to 650 m distance to the turbines, present across all study areas and independent of the structural habitat suitability at the respective site. Our results show that a disturbance-sensitive forest bird species is affected by wind energy development, and that critical-distances should be taken into account when planning wind energy development in grouse habitats.

Outdoor recreation inflicts a wide array of impacts on individual animals, many of them reflected in the avoidance of disturbed areas. The scale and spatial extent, however, at which wildlife populations are affected, are mostly unclear. Particularly in geographically isolated populations, where restricted habitat availability may preclude a relocation to undisturbed areas, effective habitat reduction may remain underestimated or even unnoticed, when animals stay in disturbed areas and only show small-scale responses. Based on telemetry data, we investigated the spatial and seasonal effects of outdoor recreation - in relation to landscape and vegetation conditions – on western capercaillie Tetrao urogallus, considering two scales, homerange and within-homerange habitat selection. We determined the distance-thresholds up to which recreation infrastructures were avoided and estimated the extent of affected habitat for the isolated Black Forest (Southwestern Germany) study population. While outdoor recreation did not affect homerange selection, strong effects on habitat use within the homerange were detected: Distance to recreation infrastructure (hiking and cross-country skiing trails, ski pistes) was the main determinant of habitat selection in winter; in summer, mountain bike trails and hiker's restaurants were avoided up to an average distance of 145m (CI: 60-1092m). Around winter-infrastructure, relative avoidance was recorded up to 320m (CI: 36-327m), it was reduced, however, when dense understory provided visual cover. Of the entire population area, between 8- 20% (summer) and 8- 40% (winter) were affected by outdoor recreation, mainly in the high altitudes. Even without evident large-scale shifts in species distribution, local-scale avoidance of outdoor recreation can substantially contribute to effective habitat reduction. Based on our results we recommend a general reduction in recreation infrastructure density in key habitats, the establishment of undisturbed wildlife refuges with a diameter of at least 800m, as well as enhancing visual protection by maintaining a strip of dense understory along trails. This article is protected by copyright. All rights reserved.

Feces of wildlife species are commonly used indicators for species’ presence or relative abundance. These might however be biased due to inconspicuousness, due to rapid decay and disappearance, or due to high site-dependent variance in decay dynamics. Mapping of indirect signs is a frequently applied approach to study habitat use or distribution of grouse species. However, only a few studies addressed avian dropping decay up to now, and no study focused on dropping decay of European grouse species. Consequently, we conducted field surveys and greenhouse trials, studying time spans over which capercaillie (Tetrao urogallus) droppings persist and factors influencing the decay rates (i.e., habitat type, small mammal access, and precipitation regime). In the field survey, after an exposure of 98 days, only 6% of droppings (n = 156) decayed completely and most droppings remained nearly unchanged. The decay rate was influenced by microsite conditions (i.e., vegetation and location), with lowest decay rates in areas with little ground vegetation or on tree stubs. Destruents were not found to play a major role in affecting decay rate. The greenhouse trial revealed the impact of precipitation on the decay rate of droppings (n = 400): under high-amount and high-intensity precipitation regime droppings decayed faster compared to low-amount and low-intensity precipitation. The slow decay rate, and resulting long time period that they can be detected, therefore means that capercaillie droppings are a valid proxy for species’ occurrence.

The precautionary principle is an essential guideline in decision making, particularly for regulating novel developments with unknown or insufficiently proven environmental impact. However, due to the inherent component of uncertainty it has been widely criticized for being “unscientific”, i.e. hindering progress without sufficient evidence. The consequential postulation, that precautionary measures are only justified if the addressed threats are plausible and the measures reasonable, calls for methods to guide action in the face of uncertainty. Using the example of species conservation versus wind-farm construction, an expanding development with hypothesized – but unexplored – effects on our model species the capercaillie (Tetrao urogallus), we present an approach that aims at compensating the lack of knowledge about the threat itself by making best use of the available knowledge about the object at risk. By systematically combining information drawn from population monitoring and spatial modelling with population ecological thresholds, we identified areas of different functionality and importance to metapopulation persistence and connectivity. We integrated this information into a spatial concept defining four area-categories with different implications for wind power development. Highest priority was assigned to areas covering the spatial and functional requirements of a minimum viable population, i.e. sites where the plausibility for threat is highest, the uncertainty as regards importance for the population is lowest, and thus the justification for precautionary measures is strongest. This gradated approach may also enhance public acceptance, as it attempts to avoid either error-minimization bias (i.e. being too restrictive or permissive) the precautionary principle is frequently criticized for.

Correlative species distribution models are frequently used to predict species’ range shifts under climate change. However, climate variables often show high collinearity and most statistical approaches require the selection of one among strongly correlated variables. When causal relationships between species presence and climate parameters are unknown, variable selection is often arbitrary, or based on predictive performance under current conditions. While this should only marginally affect current range predictions, future distributions may vary considerably when climate parameters do not change in concert. We investigated this source of uncertainty using four highly correlated climate variables together with a constant set of landscape variables in order to predict current (2010) and future (2050) distributions of four mountain bird species in central Europe. Simulating different parameterization decisions, we generated a) four models including each of the climate variables singly, b) a model taking advantage of all variables simultaneously and c) an un-weighted average of the predictions of a). We compared model accuracy under current conditions, predicted distributions under four scenarios of climate change, and – for one species – evaluated back-projections using historical occurrence data. Although current and future variable-correlations remained constant, and the models’ accuracy under contemporary conditions did not differ, future range predictions varied considerably in all climate change scenarios. Averaged models and models containing all climate variables simultaneously produced intermediate predictions; the latter, however, performed best in back-projections. This pattern, consistent across different modelling methods, indicates a benefit from including multiple climate predictors in ambiguous situations. Variable selection proved to be an important source of uncertainty for future range predictions, difficult to control using contemporary information. Small, but diverging changes of climate variables, masked by constant overall correlation patterns, can cause substantial differences between future range predictions which need to be accounted for, particularly when outcomes are intended for conservation decisions.

Outdoor recreation, particularly in winter, causes pressure on wildlife. While many species seem to adjust well to predictable on-trail recreation activities, unpredictable off-trail activities are considered harmful. Measures to minimise human disturbance require the identification of ‘conflict-sites’ where human activities are likely to interfere with the requirements of wildlife. We used winter recreation data combined with spatial modelling to predict where recreationists move from marked trails into wildlife habitats in winter and to determine the environmental factors that trigger this off-trail behaviour. We surveyed marked winter trails in the southern Black Forest, Germany, by foot or ski for tracks of people leaving the trail, with three types of recreationists distinguished: hikers, snowshoe users and cross-country skiers. Using a maximum entropy approach, the probability of leaving the trail was modelled as a function of topographic, forest structure and tourism infrastructure variables. By co...