Capercaillie Habitat Research Articles

Capercaillie (Tetrao urogallus) habitat in Romania – A landscape perspective revealed by Cold War spy satellite images

Long term analyses on habitat dynamics are challenging when data from the past is scarce. In addition, large scale perspectives are difficult to attain without proper modelling of habitat conditions. These drawbacks were overcome in the case of capercaillie in Romania with the help of satellite-based information and by finding relevant environmental variables which influence the species habitat. We used MaxEnt software with four variables (spruce distribution, elevation, precipitation and temperature in June) and 750 presence points. The model had a high predictive ability (area under the curve over 95%), elevation and spruce distribution being the most important variables. A separate set of 902 presence points was used for model crosschecking. Most of the crosscheck points (98.6%) fell inside the predicted habitat confirming the model performance. To detect habitat preferences the vegetation mosaic in 90 circles (3 km-radius) was analyzed using both historical (Cold War) and recent satellite information. The modelled habitat across the Romanian Carpathians was a mosaic of stands of different ages. Moreover, a similar structure was found inside and outside the analyzed circles: forests between 65 and 120 yr. dominated, followed by the younger classes (20–65 yr. and forests <20 yr.). The oldest class (> 120 yr.) was the least common. The majority (i.e., 90%) of the presence points used for model crosscheck fell within actively managed forests, including former large clearcuts (revealed by the Cold War spy-satellite images). This suggests that the species was tolerant to forest management and also able to recolonize areas when habitat became favorable again. Therefore, controlled forest management maintains the habitat favorability at very large scales in a shifting steady-state mosaic. This management-driven habitat together with the one produced by natural disturbances in natural forests provides favorable conditions for a habitat continuum along the Romanian Carpathians.

Habitat selection of Capercaillie (Tetrao urogallus) displaying males: Case from Rila Mountain, Bulgaria

Current habitat management of the peripheral, regionally unique, and isolated Balkan capercaillie Tetrao urogallus rudolfi Dombrowski, 1912 meta-population in Bulgaria is based on obsolete knowledge of the spatial requirements of the species. Thus, we studied the habitat availability and the patterns of use by Capercaillie adult males, at the home range scale to inform and contribute to the conservation-oriented management of the threatened subspecies and its habitats. The field study was conducted during 2014–2015 in the northeastern part of Rila Mtn., Southwestern Bulgaria. Using GPS tags (“Bird 2A”, e-obs Digital Telemetry, Grünwald, Germany), a total of 38,640 GPS fixes from 3 displaying males, associated with one lek were gained. On this basis, we calculated annual and seasonal Minimum Convex Polygons (MCP), traditionally used as a measure of the maximum area of activity. Capercaillie habitat preference was computed using Manly’s habitat selection ratios (w), design III, combined with 90% Bonferroni simultaneous confidence intervals. To calculate habitat selection, we determined surface (Steepness and Exposure), forest stand succession and vegetation cover categorical variables. The habitat and surface layers was rasterized into 8 m square pixels. At the home range (MCP) scale, tagged roosters used vegetation cover non-randomly (annual: Khi2L=5738.89, df=14, p&amp;lt;0.001; winter: Khi2L=3773.28, df=13, p&amp;lt;0.001; summer: Khi2L=3646.32, df=14, p&amp;lt;0.001), and preferred forests dominated by Scots pine and Macedonian pine, such as the annual selection of Scots pine and summer selection of Macedonian pine are significantly different. In terms of forest stage succession, roosters used forest stages non-randomly (annual: Khi2L=3492.57, df=8, p&amp;lt;0.001; winter: Khi2L=2075.18, df=8, p&amp;lt;0.001; summer: Khi2L=1670.1, df=6, p&amp;lt;0.001), and demonstrated clear avoidance of forests stands in age classes: “0 to 40” and “41 to 80” years within the summer and annual ranges. The roosters demonstrated significant preference for southeastern exposure during the winter and annually, and significant overall avoidance of northern exposure, as well as avoidance of north-eastern aspect during the winter and south aspect during the summer (annual: Khi2L=4671.87, df=18, p&amp;lt;0.001; winter: Khi2L=3909.04, df=16, p&amp;lt;0.001; summer: hi2L=3095.84, df=18, p&amp;lt;0.001). The slope class “63.1 to 73o” was not used. In the summer, Capercaillie males significantly preferred slopes within the class “27.1 to 36o” and avoided the classes “0 to 9o”, “9.1 to 18o” and “54.1 to 63o”. The birds also demonstrated significant avoidance of flat terrains within the “0 to 9o” class annually (annual: Khi2L=608.24, df=17, p&amp;lt;0.001; winter: Khi2L=1148.37, df=16, p&amp;lt;0.001; summer: Khi2L=906.54, df=17, p&amp;lt;0.001).

Altitudinal Shift of Tetrao urogallus in an Alpine Natura 2000 Site: Implications for Habitat Restoration

Capercaillie (Tetrao urogallus L.), a territorial galliform species, is known to prefer mature conifer stands with canopy gaps and a vigorous understory of ericaceous species. Capercaillie is a useful umbrella species that has recently shown declining population trends and distribution changes in its southern geographic range. We aim to identify and assess the possible changes in summer capercaillie habitat selection between 2001 and 2011 in the Scanuppia Natura 2000 site (south-eastern Alps). The area is dominated by spruce (Picea abies (L.) Karsten) forests, followed by mixed forests, scrub, and open habitats. In both years, summer presence–absence of capercaillie was verified through the detection of droppings over 10 m radius circular plots located along contour lines (1500–1800 m). A set of environmental and habitat features was also surveyed. While overall population numbers remain unchanged over the surveyed period, results have shown an altitudinal shift in capercaillie distribution. Habitat variables had a stronger effect on the presence of capercaillie in 2001 than in 2011. Land cover and climate change are likely among the drivers of the shift in altitudinal distribution. This confirms the relevance of habitat restoration actions and to monitor changes in factors explaining capercaillie habitat selection.

Evaluating landscape connectivity in fragmented habitats: Cantabrian capercaillie (Tetrao urogallus cantabricus) in northern Spain

Cantabrian capercaillie (Tetrao urogallus cantabricus) is listed as endangered according to IUCN criteria. The high degree of fragmentation and anthropogenic disturbances in capercaillie habitat suggests that habitat patterns may be related to decline of capercaillie populations in northern Spain. The objectives of this study are: (1) determining critical territories for the maintenance of capercaillie connectivity; and (2) evaluating the importance of public forests and their appropriate management to maintain the habitat connectivity for this species. This study is focused on northern Spain, where forest areas are critical for the maintenance of capercaillie. We applied connectivity methodologies based on morphological spatial pattern analysis (MSPA) and the probability of connectivity (PC). The results of the MSPA were incorporated into a standard GIS and compared with the spatial distribution of the public forest. Most of the valuable areas for connectivity were inside the public forests. Moreover, these public forests mainly form continuous features. Therefore, forest planning and management, mainly in public forest, should approach this problem including connectivity considerations and, more specifically, identifying the most critical forest sites for the maintenance of capercaillie habitat.

Forest management impacts on capercaillie (Tetrao urogallus) habitat distribution and connectivity in the Carpathians

Distribution and connectivity of suitable habitat for species of conservation concern is critical for effective conservation planning. Capercaillie (Tetrao urogallus), an umbrella species for biodiversity conservation, is increasingly threatened because of habitat loss and fragmentation. We assessed the impact of drastic changes in forest management in the Carpathian Mountains, a major stronghold of capercaillie in Europe, on habitat distribution and connectivity. We used field data surveys with a forest disturbance dataset for 1985–2010 to map habitat suitability, and we used graph theory to analyse habitat connectivity. Climate, topography, forest proportion and fragmentation, and the distance to roads and settlements best identified capercaillie presence. Suitable habitat area was 7510 km2 in 1985; by 2010, clear-cutting had reduced that area by 1110 km2. More suitable habitat was lost inside protected areas (571 km2) than outside (413 km2). Habitat loss of 15 % reduced functional connectivity by 33 % since 1985. Forest management, particularly large-scale clear-cutting and salvage logging, have substantially diminished and fragmented suitable capercaillie habitat, regardless of the status of forest protection. Consequently, larger areas with suitable habitat are now isolated and many patches are too small to sustain viable populations. Given that protection of capercaillie habitat would benefit many other species, including old-growth specialists and large carnivores, conservation actions to halt the loss of capercaillie habitat is urgently needed. We recommend adopting policies to protect natural forests, limiting large-scale clear-cutting and salvage logging, implementing ecological forestry, and restricting road building to reduce forest fragmentation.

Severe decline in Cantabrian Capercaillie Tetrao urogallus cantabricus habitat use after construction of a wind farm

SummaryTetrao urogallus cantabricus is the most endangered capercaillie subspecies and unlike the others it inhabits deciduous forests in the Cantabrian Mountains (north-west Spain). Its southernmost distribution occurs in Mediterranean forests outside conservation areas where wind farm construction is increasing. We surveyed Cantabrian Capercaillie presence in a wintering site one year before and four years after wind farm construction. Sign abundance greatly decreased after wind farm construction indicating a likely negative effect on Cantabrian Capercaillie habitat use. According to the precautionary principle, in order to conserve Cantabrian Capercaillie, all its range should be legally protected to avoid further wind farm construction and human disturbance.

Waldbauliche Massnahmen für das Auerhuhn im Sonderwaldreservat Amden: ein erstes Fazit

Silvicultural habitat restoration measures for the capercaillie in the special forest reserve of Amden: a first review As a threatened forest grouse species, the capercaillie (Tetrao urogallus) depends on conservation actions in core areas of its Alpine distribution. In this study, we looked at the species' response to silvicultural measures in the special forest reserve of Amden in the canton of St. Gallen, Switzerland. Here, silvicultural measures were taken between 2006 and 2009 in stands that had previously been classified as less or not suitable for capercaillie. In summer 2010, we investigated how stands used by the species differed from unused ones by relating indirect evidence of species presence with forest structural and compositional variables. Evidence of species' habitat use was found in 12 out of 33 surveyed stands. Used stands showed a significantly higher share of bilberry in the ground vegetation layer, a higher proportion of coniferous trees and a lower canopy cover. Furthermore, the proportion of suitable habitat in immediate vicinity of the treated forest stand was higher in used stands. Our results support that habitat restoration by logging is a promising method to improve capercaillie habitat, in particular in fir-spruce forests, where the effectivity of restoration measures was higher compared to fir-beech forests. Hence, managing guidance for the future selection of stands for restoration should be based on habitat suitability of the stand itself and on an appropriate habitat quality of adjacent forest stands.

An evaluation of thinning to improve habitat for capercaillie (Tetrao urogallus)

In Scots pine (Pinus sylvestris) forests the composition of the ground flora can be affected by the amount of light reaching the forest floor, influencing the balance between the three common ericaceous shrubs bilberry (Vaccinium myrtillus), cowberry (Vacciniumvitis-idaea) and heather (Calluna vulgaris). A pinewood ground flora with more than 20% bilberry cover is considered good habitat for capercaillie (Tetrao urogallus), a large forest grouse of considerable conservation interest throughout Europe. Old, semi-natural Scots pine woodland is considered its prime habitat in Scotland, although this is limited in area compared to twentieth century planted forests. Action to manipulate environmental conditions within Scots pine plantations by altering light levels to favour bilberry through thinning and felling could potentially increase greatly the area of available capercaillie habitat in Scotland. We implemented a five year study to look at bilberry response to variable intensity thinning in two Scots pine plantations, where thinning followed management guidance for capercaillie available at the time. Bilberry was present in both forests but a positive response to thinning was not universal; although at both sites bilberry cover increased significantly over five years with levels >20% cover reached, this could only be attributed to the thinning treatment at one of the sites. A treatment of small patch clearfelling did not lead to losses in bilberry. Management guidance published after the trial had begun, identified the appropriate intensity of thinning for enhancing bilberry cover at our study sites, indicated by the relative increase of bilberry in the plots where the prescription had been followed. Although there was no significant treatment effect by year five, 42% average bilberry cover was reached at one site tested. However the format of this guidance, a range of stem density-tree height combinations, was difficult to apply using typical forest management data and we explore redefining the guidance as a post thinning stand basal area range. We suggest >22 to <31m2ha−1 basal area would be appropriate in Scots pine plantations established at normal spacing and subject to the commonest form of selective thinning regime. This range in basal area can be achieved without conflicting with management for timber production. Our results also support small patch clearfelling as a method of diversifying plantation age structure which is compatible with maintaining capercaillie brood habitat.

Burning and mowing as habitat management for capercaillie Tetrao urogallus: An experimental test

In Scots pine Pinus sylvestris forests, the important ecological effects of natural fires could be emulated using prescribed fire. Species that may benefit from fire effects include capercaillie Tetrao urogallus, a large forest grouse. A key component of forest habitats for capercaillie is the ericaceous shrub, bilberry Vaccinium myrtillus, which is eaten by capercaillie, and supports abundant arthropods, taken by young chicks. We carried out an experiment testing whether prescribed burning would be a valuable technique for capercaillie habitat management. The study took place at Abernethy Forest, the largest ancient native pinewood in Britain, and a key capercaillie site, holding c 8–20% of the British population. Prescribed fire in woodland is highly novel in Britain. We therefore also tested mowing, which might replicate some fire effects more cheaply and safely. Twenty-five experimental blocks were established within open pine stands with ground vegetation including bilberry, but dominated by heather Calluna vulgaris. Each block held three 700 m 2 plots, randomly assigned to control, mow and burn. Vegetation, arthropods and capercaillie dung were monitored over a 7-year period, including 1 year prior to treatment. Mean bilberry cover, initially around 12%, increased in mown and burnt areas, but there were also increases in controls, following unusual natural die-back of heather. By the sixth season after treatment, bilberry cover was significantly higher in burnt and mown areas than controls, averaging 27% (95% confidence intervals 24–30), compared to 20% (19–21) in controls. Biomass of spiders, an important dietary group for capercaillie chicks, as measured by pitfall trapping, was significantly higher in burnt and mown plots than controls, by about 56% (38–76). However, biomass of caterpillars, often considered a more important dietary group, did not show clear differences between treatments. An alternative analysis was used to ‘statistically remove’ natural heather die-back; this enhanced the treatment differences in bilberry cover and spider biomass. Capercaillie dung counts suggested that burnt, and especially mown areas, had more summer capercaillie usage than controls. Capercaillie conservation at sites similar to Abernethy is likely to benefit from either prescribed fire or mowing, because these techniques increase bilberry and spider abundance. This study illustrates the value of collaboration between researchers and land-managers, in developing and testing novel management techniques. We support the idea that ‘dominance reduction’, delivered through managed disturbance, offers a general principle to guide land-managers wishing to maintain biodiversity, particularly where key species, like capercaillie, are strongly associated with sub-dominant plant species like bilberry.

Assessing the spatio-temporal pattern of winter sports activities to minimize disturbance in capercaillie habitats

Outdoor activities may have serious consequences for wildlife species that are sensitive to human disturbance. The pressure of outdoor activities on natural landscapes has increased dramatically in recent decades. However, we generally lack information on the spatial and temporal patterns of outdoor activities – a fact that makes it difficult to quantify the impact on wildlife and thus to implement and justify measures to constrain outdoor activities. In the winter seasons 2008 / 2009 and 2009 / 2010, we equipped 303 recreationists in the Val Müstair Biosphere Reserve, eastern Swiss Alps, with GPS loggers to record their spatial and temporal pattern of landscape use. We then analysed how the resulting pattern of spatial use overlapped with the habitat of capercaillie Tetrao urogallus, an endangered woodland grouse species that is highly sensitive to disturbance. For our study we used the official capercaillie core winter habitats observed by the game wardens of the Canton Grisons. The recorded 319 trips of 188 backcountry skiers and snowboarders and 231 trips of 115 snowshoers combined show an inhomogeneous use of subareas in the region. With one exception, the trips are located in the main valley and the adjoining southern and northern slopes and peaks. The trips of snowshoers result in a dispersed use pattern across the main valley, while the trips of the backcountry skiers and snowboarders are concentrated more on official and popular routes. Rarely did recreationists trespass official wildlife sanctuaries or cross capercaillie habitat patches. However, one official, very popular backcountry skiing route crosses one of the largest capercaillie habitats. Here the recorded trips show wide-ranging spatial use with many connectors to the main route. As a consequence, this capercaillie habitat patch is dissected into smaller undisturbed patches. GPS logging in combination with camera trap data provides detailed information on the spatio-temporal land-use pattern of outdoor activities. Based on these data, we identified a conflict of interest in the Val Müstair Biosphere Reserve that has to be resolved by management in a joint participatory process with the main stakeholders. Our methods and results could be transferred to other Alpine regions and be used for any land cover types. In this way we hope to contribute to mitigating conflicts between human outdoor activities and wildlife populations.

Aufzuchtshabitate für Auerhühner – ein Experiment mit Haushuhnküken | Capercaillie chick habitat – an experiment with barn fowl chicks

Capercaillie (Tetrao urogallus) populations in Switzerland declined seriously in the past decades. The national capercaillie action plan defines actions to improve forest structure and composition in order to further the populations of the largest grouse species. These habitat measures should focus on improving summer habitat for hens with chicks, because winter habitats are available in good quality and quantity. However, our knowledge on reproduction habitats in alpine conditions is limited. In this study, we investigated microclimatic conditions, i.e. plant wetness, and movement ability of barn fowl chicks in seven characteristic field layer types in the northern Swiss Lower Alps. In the experiment on movement ability, we worked with barn fowl instead of capercaillie chicks for methodological reasons. In the bilberry-dominated vegetation, we measured a significantly lower quantity of water than in the vegetation types without bilberry. In the movement experiment, we found no significant differences between the vegetation types. As a qualitative result, we observed that the chicks moved easily even in high (&amp;gt; 30 cm) and close bilberry vegetation. Our results suggest that bilberry-dominated vegetation provides better conditions for grouse chicks than wet meadows and pastures, because less water adheres to the bilberry plants. Thus, the chicks get less wet in bilberry vegetation, which probably has a positive influence on the survival of the chicks. Even tall and dense vegetation seems not to impede the movement of the chicks. The results of our experiment may not be directly transferable to the demands of capercaillie chicks. Nevertheless, our study provides further evidence for the importance of bilberry as capercaillie chick habitat, especially in regions with high precipitations.

Capercaillie (Tetrao urogallus) habitat characteristics in north-boreal Finland

This study aimed to identify tools for taking capercaillie habitats into consideration in forest management. This would provide new alternatives for ecologically more sustainable forest management. Capercaillie summer and winter locations, from wildlife monitoring counts (1998–2004) in northern Finland, and reference, non-capercaillie locations were combined with forest planning data, and the area proportions of different landscape classes in an 800-m radius circle surrounding capercaillie and reference locations were compared. Thinning stands (in summer and winter) and spruce mires (in summer) were more abundant in capercaillie habitats than in reference landscapes, whereas e.g. seedling stands, mature stands and waste land areas were less abundant. The relative habitat use was highest in mean tree diameter (DBH) classes from 10.5 to 14.5 cm in summer habitats of adult capercaillie in heath forests, whereas in peatland forests, in brood habitats and in winter habitats it peaked in diameter classes 14.5 to 18.5 cm. The tree layer density was positively associated with the relative habitat use. A trend of lower habitat use was detected in the largest diameters (17–40 cm) in comparison to middle-sized diameters (10–16 cm) in heath forests, but not in peatland forests. Relatively young managed forests (age 30–40 years or more) can form suitable capercaillie habitats in north-boreal forests. However, this suitability is not necessarily permanent. Understorey management, longer rotations and multicohort forest management are suitable tools for capercaillie habitat management, because they can increase the available cover close to the ground, canopy cover, overall forest cover at the landscape scale and bilberry cover.

Capercaillie (&lt;em&gt;Tetrao urogallus&lt;/em&gt; L.) habitats in managed Finnish forests – the current status, threats and possibilities

The aim of this study was to provide applicable knowledge for taking capercaillie into consideration in forest management and thus progress ecologically sustainable forestry. Capercaillie is a respected game species, but it also has indicator and umbrella species characteristics. Therefore capercaillie is closely linked to many other species. The study focused on the question: which structural characteristics of forest are important for the capercaillie? To gain a thorough view of capercaillie habitat needs, various capercaillie habitats were studied at several spatial scales in Finland in 1990s and 2000s. Species data were mostly from the wildlife monitoring counts. Forest planning data from Metsahallitus and data from the national forest inventories formed the landscape data. At large spatial scale (2500 km study units) the capercaillie population density was positively associated with the proportion of young thinning stands throughout the country. The association between capercaillie and young thinning stands was also positive at smaller scales in summer habitats, winter habitats and lek surroundings in northern Finland, where also the stand density was found to be positively associated with capercaillie in the summer habitats. The positive relationship between capercaillie and mature forests was found at the beginning of 1990s, but later this association was weak. The managed boreal forests become suitable for the capercaillie within 30 – 40 years, and so the large areas clear-cut in 1950s and 1960s in Finland became suitable for the capercaillie mostly in the 1990s. But the habitat quality may also decrease in the later successional stages of forest. The shortterm effects of thinnings on the capercaillie microhabitat quality can vary depending on the stand characteristics and season, and between adult birds and broods, but in the long term low cover on the ground may be the factor, which reduces the habitat quality in older managed forests especially in the low-productive areas and sites. Overall forest cover at the landscape scale, canopy cover and cover on the ground are important forest characteristics for the capercaillie. Longer rotations, understorey management and selective cuts are suitable methods to increase the capercaillie habitat availability and quality in the managed Finnish forests. Capercaillie habitat management calls also for spatial planning and preserving the availability of pine specifically in southern Finland. Also the costs and benefits of cutting residue management and possibilities to reduce the ditch restoration intensity in peatland forest management deserve a careful evaluation in the future. Furthermore, the connections between the abovementioned forest characteristics and other species deserve also to be studied.

Ongoing population decline and range contraction in Norwegian forest grouse

Forest grouse diverge in niche, where Capercaillie Tetrao urogallu s thrives in older forests, Hazelgrouse Bonasa bonasia is a habitatspecialist (middle-aged decidous-rich coniferous forest) and Black Grouse T. tetrix is an early succesionalist. We analysed the hunting statistics over four decades in Norway to explore divergence among forest grouse in spatio-temporal trends and discuss these findings in relation to factors changing habitats for these species. Overall, modern forestry has continuously modified the forests, especially Hazelgrouse and Capercaillie habitats. In the same time, climate has become warmer and more humid pushing climate zones northwards. In this study, all species revealed declines compared to the 1970s, especially profound into south and in the northernmost county. This response was strongest for Hazelgrouse and next Capercaillie. Central, inland counties along the Swedish border reveal smaller declines and are probably source areas. We propose that the effect of climate and forestry interact to reduce habitat optimality for forest grouse, and that these effects are stronger in sinks, potentially initiating range-contraction.

Changes in landscape-scale habitat selection of capercaillie (Tetrao urogallus) in managed north-boreal forest

We studied changes in habitat selection of capercaillie in northern Finnish boreal forests at two spatial scales during two time periods, 1989–1992 and 2000–2003. We studied capercaillie densities and their changes between the study periods in relation to the landscape class proportions within 3-km buffer zones around the wildlife triangle center points. Furthermore, we compared the landscape class proportions in 800-meter buffer zones around capercaillie wildlife triangle count observations and around the counted wildlife triangle transects using t-tests and compositional analysis. At the local population scale (3 km) the change in adult density between the study periods was associated positively with the proportion of young thinning stands in 2003 and reversely with the mature stand (1992 and 2003) and clear-cut (1992) proportions. Capercaillie juvenile and pooled densities during 2000–2003 were positively associated with the advanced thinning stand proportion in 2003. At the capercaillie home range scale (800 m) habitats were rich in mature stands during 1989–1992 in relation to available habitats, but not during 2000–2003 when young thinning stands were more abundant in relation to available habitats. Relatively young managed forests can be suitable for capercaillie, but mature managed forests as capercaillie habitats may have deteriorated between the study periods. Spatial planning may help to form suitable areas that are large enough for the species, but the highest potential may lay in the forest stand scale, where increased cover on the ground could promote the habitat quality.

Large-Scale Landscape Composition and Capercaillie (Tetrao urogallus) Density in Finland

We studied the relationship between landscape composition and capercaillie density in 50 km × 50 km grids in Finland, where modern forestry started in the 1950s and most of the forests are in commercial use. Capercaillie density was positively associated with the young thinning stand proportion throughout the country, but unlike in numerous older studies, it wasn't positively associated with the mature stand proportion in any part of the country. In central Finland this relationship was even negative. In central and southern Finland capercaillie density was associated positively with the forest land proportion, and negatively with the open area proportion. Results suggest that the overall amount of the forest cover is important for the capercaillie, and that clear-cut areas in the 1950s and 1960s, known as ‘large age classes’, have developed as suitable for them. A new aspect based on results is the potential reduction in the mature forest quality as capercaillie habitats.

Ski tourism affects habitat use and evokes a physiological stress response in capercaillie Tetrao urogallus: a new methodological approach

Summary Human outdoor recreational activities are increasing and have a significant impact on wildlife. There are few methods suitable for investigating the response of rare and endangered species to human recreational activities, although the impact can be assessed at various scales by measuring both physiological and behavioural responses to disturbance. Capercaillie Tetrao urogallus are suffering strong population declines throughout central Europe. We examined the effects of ski tourism on capercaillie habitat use and adrenocortical activity, measured non‐invasively in droppings. During three winters, 2003–06, we radio‐tracked 13 capercaillie. In the southern Black Forest in Germany, we sampled 396 droppings of these and additional individuals before and after the start of the ski season. We tested whether the intensity of human winter recreational activities affected home range location and habitat use, and we identified those factors influencing the concentration of corticosterone metabolites (CM) in droppings. Capercaillie used habitats subject to ski tourism. Although the latter did not affect home range location, capercaillie preferred undisturbed forests within their home ranges and avoided areas with high recreation intensity in the ski season. Faecal CM levels of individuals in areas with low recreation intensity were significantly lower than those in areas with moderate or high recreation intensity during the entire study period. We conclude that ski tourism affects both habitat use and endocrine status in capercaillie, with potential negative consequences on body condition and overall fitness. Synthesis and applications. This study demonstrates the relevance of studying wildlife responses at various temporal and spatial scales, and the value of using multiple methods applied to the same individuals to monitor the impact of human recreational activities on a free‐ranging species. In order to protect capercaillie populations, we recommend that managers keep forests inhabited by capercaillie free from tourism infrastructure and retain undisturbed forest patches within skiing areas.

A Model for Evaluating the ‘Habitat Potential’ of a Landscape for Capercaillie Tetrao urogallus: A Tool for Conservation Planning

Most habitat models developed for defining priority conservation sites target areas currently exhibiting suitable habitat conditions. For species whose habitats have been altered by land use practices, these models may fail to identify sites with the potential of producing suitable habitats, if management practices were modified. Using capercaillie Tetrao urogallus as an example, we propose a model for evaluating the potential of ecological conditions at the landscape level to provide suitable habitat at the local scale. Initially, we evaluated the influence of selected landscape parameters on the structural characteristics of vegetation relevant to capercaillie. Then we used capercaillie presence data and an ecological niche factor analysis (ENFA) to identify landscape and land use variables relevant to capercaillie habitat selection. We also studied the effect of scale on predictive model quality. Despite high variance, correlations between landscape variables and forest structure were detected. The greatest influence on forest structure was recorded for climate and soil conditions, which were also found to be the best predictors of capercaillie habitat selection in the ENFA. The final model, retaining only two landscape variables (soil conditions and days with snow) and three land use variables (proportion of forest, distance to roads and forest-agricultural borders), explained a high degree of capercaillie habitat selection, even before considering patch size and connectivity. By restricting the analyses to areas with stable subpopulations and a set of relatively stable landscape variables capable of explaining habitat quality at a local scale, we were able to identify areas with long-term relevance to conservation of capercaillie.

Integrating landscape connectivity in broad-scale forest planning through a new graph-based habitat availability methodology: application to capercaillie (Tetrao urogallus) in Catalonia (NE Spain)

The loss of connectivity of forest landscapes is seriously hindering dispersal of many forest-dwelling species, which may be critical for their viability and conservation. In this context, explicitly incorporating connectivity considerations is an important challenge in current forest planning and management, but as yet there is a lack of operative methods for appropriate decision making in this respect. We describe a new methodology based on graph structures and a habitat availability index (integral index of connectivity) that integrates forest attributes (like habitat quality) and network connectivity in a single measure. We apply this methodology to examine the connectivity of the highly fragmented habitat of capercaillie (Tetrao urogallus) in Catalonia (NE Spain), where the threatened status of this forest bird species calls for landscape-level forest planning solutions. We analyse data on the distribution of capercaillie forest habitat at 1 km spatial resolution obtained from the recent Catalan Breeding Bird Atlas. We determine the functionally connected regions existing within its habitat distribution and identify the forest habitat areas that are more important for the maintenance of overall landscape connectivity for this species. Based on these results, we provide recommendations on certain critical public forests where management oriented to the conservation of capercaillie habitat is more necessary. These results highlight the potential and practical interest of the proposed methodology for successfully integrating landscape connectivity in broad scale forest planning.

Die Entwicklung der Wälder auf der Schwägalp im 20. Jahrhundert und ihre Bedeutung für den Lebensraum des Auerhuhns (Tetrao urogallus L.) | Forest development on the Schwägalp in the 20th century and its significance for the habitat of capercaillie (Tetrao urogallus L.) (reviewed paper)

Capercaillie populations in Switzerland declined significantly during the 20th century. The loss of suitable habitats is considered to be the main reason for this decline. For the Pre-Alpine region of the Schwägalp, aerial photographs and a statistic model were used to quantify changes in the availability and distribution of capercaillie habitat. We detected a loss of suitable habitats. However, this loss alone can not explain the extensive decline in the population of this endangered species.