Vor zwölf Jahren wurde vom Bundesamt für Umwelt der Aktionsplan Auerhuhn Schweiz in Kraft gesetzt. Eine Zwischenbilanz über seine Wirkung zeigt, dass das Verbreitungsgebiet des Auerhuhns in den Bündner Alpen sowie am zentralen und östlichen Alpennordrand mehr oder weniger stabil geblieben ist. Auf einem Höhenzug ist zudem eine Wiederbesiedlung gelungen. Auch die Populationsgrössen scheinen stabil zu verlaufen, sofern die verfügbaren Daten eine Beurteilung zulassen. Im Jura dagegen hat sich die dramatische Verkleinerung des Auerhuhn-Verbreitungsgebiets unvermindert fortgesetzt. Bereits vor 15 Jahren wurde in Amden im Kanton St. Gallen ein Sonderwaldreservat mit dem Hauptziel der Auerhuhn-Förderung gegründet. Die waldbauliche Wirkungskontrolle zeigt, dass hier die Lebensraumqualität maximal zehn Jahre nach Umsetzung der Massnahmen bereits deutlich besser war. Zudem wurde etwa die Hälfte der aufgewerteten Flächen vom Auerhuhn neu als Lebensraum angenommen. Mit geeigneten waldbaulichen Massnahmen kann die Eignung eines Waldes als Lebensraum für Auerhühner deutlich verbessert werden. Besonders erfolgreich ist man damit an Standorten mit Nadelwäldern oder Mischwäldern, in denen Laubholzarten nicht zu dominant werden.

Modeling the population dynamics of patchily distributed species is a challenge, particularly when inference must be based on incomplete and small data sets such as those from most species of conservation concern. Open population spatial capture-recapture (SCR) models are ideally suited to quantify population trends, but have seen only limited use since their introduction. To investigate population trend and sex-specific population dynamics, we applied an open SCR model to a capercaillie ( Tetrao urogallus ) population in Switzerland living in eight distinct forest patches totalling 22 km 2 within a region of 908 km 2 . The population was surveyed using genetic sampling of scat in 2009, 2012 and 2015. We fit an open SCR model with sex-specific detection and population dynamics parameters while accounting for the patchy distribution of habitat and the uncertainty introduced by observing the population in three years only. Between 2009 and 2015, a total of 143 males, 112 females and 4 individuals of uncertain sex were detected. The annual per capita recruitment rate was estimated at 0.115 (SE 0.0144) for males and 0.127 (0.0168) for females. The estimated annual survival probability for males was 0.758 (0.0241) and 0.707 (0.0356) for females. The population trajectory implied by these survival and recruitment estimates was a decline of 2% per year; however, the sex specificity of the model revealed a decline in the male population only, with no evidence of decline in the female population. Further, the population decline observed in males was explained by the demography of just two of the eight patches. Using a customized open population SCR model, we determined that the endangered capercaillie in our Swiss study area had a stable female population and a declining male population, with the male decline due to population dynamics in a subset of the study area. Our study highlights the flexibility of open population SCR models for assessing population trajectories through time and across space and emphasizes the desirability of estimating sex-stratified population trends especially in species of conservation concern.

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.

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.

Die Entwicklung der Verbreitung der Schweizer Brutvögel ist ein Spiegelbild unseres Umgangs mit Natur und Umwelt. Mit dem Brutvogelatlas 2013-2016 wurden die aktuellen Vorkommen, die Häufigkeit und die Höhenverbreitung aller Brutvögel der Schweiz und des Fürstentums Liechtenstein dokumentiert. Zusammen mit den drei früheren Brutvogelatlanten lassen sich damit die Veränderungen in der Schweizer Vogelwelt in den letzten 20 bis 60 Jahren aufzeigen. So weist, im Vergleich zu anderen Lebensraumgilden, der Bestandsindex der Waldvögel den positivsten Verlauf auf. Trotzdem gibt es auch im Wald gefährdete Vogelarten mit sehr kleinen und/oder abnehmenden Beständen. Es handelt sich primär um Arten, die auf hohe Alt- und Totholzmengen, lichte Wälder oder Waldränder mit breiten Übergangszonen zum Kulturland angewiesen sind.

Breeding bird fauna in a coniferous forest in the northern Prealps after storm Lothar In a 70-hectare large coniferous forest located on the northern edge of the Alps in central Switzerland, Canton of Obwalden, at an altitude of 1260 to 1550 metres above sea level, we surveyed the local breeding bird fauna in 2002 and 2013 by means of point counts as well as additional area searches for rare species. In December 1999, hurricane Lothar caused two large windthrow areas and several smaller areas with scattered throws in the survey range. We found a total of 48 breeding bird species, which is a very diverse species composition for a mountain forest. In the eleven years between surveys, a decline in distribution or abundance was recorded for four species, while seven species showed an increase; a further four species showed no change. For the remaining species, the data sets were too small to reliably estimate changes. A comparison with forest structure data provided by the Swiss Federal Institute of Forest, Snow and Landscape Research WSL revealed that for five bird species, the changes in distribution or abundance could be explained at least partially by forest succession. In order to obtain realistic distribution and abundance values in this kind of breeding bird survey, it is essential to collect large enough samples and to consider the detection probability of each individual species using appropriate statistical methods.

We conducted a survey of an endangered and cryptic forest grouse, the capercaillie Tetrao urogallus, based on droppings collected on two sampling occasions in eight forest fragments in central Switzerland in early spring 2009. We used genetic analyses to sex and individually identify birds. We estimated sex-dependent detection probabilities and population size using a modern spatial capture-recapture (SCR) model for the data from pooled surveys. A total of 127 capercaillie genotypes were identified (77 males, 46 females, and 4 of unknown sex). The SCR model yielded a total population size estimate (posterior mean) of 137.3 capercaillies (posterior sd 4.2, 95% CRI 130-147). The observed sex ratio was skewed towards males (0.63). The posterior mean of the sex ratio under the SCR model was 0.58 (posterior sd 0.02, 95% CRI 0.54-0.61), suggesting a male-biased sex ratio in our study area. A subsampling simulation study indicated that a reduced sampling effort representing 75% of the actual detections would still yield practically acceptable estimates of total size and sex ratio in our population. Hence, field work and financial effort could be reduced without compromising accuracy when the SCR model is used to estimate key population parameters of cryptic species.

Due to a national species action plan, in Switzerland the capercaillie (Tetrao urogallus) stands in the center of the forestry measures taken to promote the preservation of biodiversity in mountain forests. Special forest reserves are suitable instruments for the conservation of capercaillie because the consecutive reduction of standing stock is the most important measure to improve the species' habitat quality in Swiss forests. In this article, we describe the ecological conditions, fundamentals and the instruments used to delineate the special forest reserve of Amden (Canton St Gallen, Swiss Pre-Alps) in 2006. Further, we report the planning of the measures and the first experiences with the actions done. The special forest reserve encompasses a national priority area for capercaillie conservation and has a surface of 1772 ha. Forest, particularly high-montane fir-beech forest and high-montane fir-spruce forest, interspersed with many mires and fens, covers 55 percent. For the planning we used an area-wide map of forest stands and one showing habitat suitability. We derived the measures that have to be taken in the near future by comparing the actual and the target state of the forest stands on eleven habitat reference areas. The range of the measures includes thinning for regeneration, the creation of flight and escape aisles, the partial clearing of the proximity of roosting trees, the regulation of young growth in favour of conifers, the planting of silver firs, forest edge improvements, increasing the number of lying logs and pulling down trunks. Until the end of 2009 52 harvests had been done with a volume of 14000 m3, 8 ha of young growth were tended and 3700 young silver firs planted. The procedure has worked well during the first four project years. But only success control regarding the development of habitat quality and the species' population response will show how effective the management concept was. The newly developed principle of habitat reference areas that has been applied for the first time will provide valuable support for such a task ten years after the first measures have been taken.

The present study investigated whether the flushing distance, the territorial use and the stress hormone physiology of the capercaillie (Tetrao urogallus) were influenced in the winter by the presence of a large number of people engaged in sporting activities. In most cases flushing distances were greater, and higher concentrations of stress hormone were found in the blood serum, in areas having a high intensity of sporting activities than in forest stands relatively undisturbed by tourists. During the ski season capercaillie avoided forest patches within their home ranges where there was a high level of recreational activity. The results lead to the conclusion that intensive winter tourism can be a serious threat to the remaining capercaillie populations in middle Europe. It is recommended that the construction of new recreational facilities and new developments should be avoided in the most important habitats for capercaillie. The important habitats which today already lie in the immediate vicinity of areas intensively used by tourists could clearly receive enhanced status, according to each situation, either as tranquility areas for wildlife where entrance is forbidden or with regulations requiring winter tourists to stay on trails.

Results from the monitoring programs of the Swiss Ornithological Institute show that the breeding populations of several forest species for which deadwood is an important habitat element (black woodpecker, great spotted woodpecker, middle spotted woodpecker, lesser spotted woodpecker, green woodpecker, three-toed woodpecker as well as crested tit, willow tit and Eurasian tree creeper) have increased in the period 1990 to 2008, although not to the same extent in all species. At the same time the white-backed woodpecker extended its range in eastern Switzerland. The Swiss National Forest Inventory shows an increase in the amount of deadwood in forests for the same period. For all the mentioned species, with the exception of green and middle spotted woodpecker, the growing availability of deadwood is likely to be the most important factor explaining this population increase.

Numbers and distribution of Capercaillie Tetrao urogallus in Switzerland 2001 and their changes in the 19th and 20th century. - Male Capercaillie were censused at their leks in spring 2001 in most parts of their range in Switzerland. A large part in the canton of Grisons was not censused with the same method but by a stratified sampling of tracks, droppings and feathers. The Capercaillie is distributed in the Jura mountains, along the northern slopes of the Alps and in the central Alps of the canton of Grisons. On 147 leks, 252 Ca- percaillie were counted. The total number of Capercaillie males in Switzerland is estimated to be between 450 and 500. In 196 8/ 1971 and in 1985 two censuses had been carried out with the same method. The first revealed an estimated number of Capercaillie males of at least 1100, the second of 55 0- 650. Since 1985, the range has shrunk, too. Capercaillie has almost completely disappeared from the northwestern slopes of the Alps. The main reasons for the long-term negative trend in population numbers of Capercaillie seem to be changes in forest structure and human disturbances. Meteorological data suggest that between 1985 and 2001 the decline has been overlayed by population fluctuation caused by changing weather conditions.

Numbers and distribution of Capercaillie Tetrao urogallus in Switzerland 2001 and their changes in the 19th and 20th century. – Male Capercaillie were censused at their leks in spring 2001 in most parts of their range in Switzerland. A large part in the canton of Grisons was not censused with the same method but by a stratified sampling of tracks, droppings and feathers. The Capercaillie is distributed in the Jura mountains, along the northern slopes of the Alps and in the central Alps of the canton of Grisons. On 147 leks, 252 Capercaillie were counted. The total number of Capercaillie males in Switzerland is estimated to be between 450 and 500. In 1968 / 1971 and in 1985 two censuses had been carried out with the same method. The first revealed an estimated number of Capercaillie males of at least 1100, the second of 550 – 650. Since 1985, the range has shrunk, too. Capercaillie has almost completely disappeared from the northwestern slopes of the Alps. The main reasons for the long-term negative trend in population numbers of Capercaillie seem to be changes in forest structure and human disturbances. Meteorological data suggest that between 1985 and 2001 the decline has been overlayed by population fluctuation caused by changing weather conditions.