The role of scale in ecology is widely recognized as being of vital importance for understanding ecological patterns and processes. The capercaillie (Tetrao urogallus) is a forest grouse species with large spatial requirements and highly specialized habitat preferences. Habitat models at the forest stand scale can only partly explain capercaillie occurrence, and some studies at the landscape scale have emphasized the role of large-scale effects. We hypothesized that both the ability of single variables and multivariate models to explain capercaillie occurrence would vary with the spatial scale of the analysis. To test this hypothesis, we varied the grain size of our analysis from 1 to just over 1100 hectares and built univariate and multivariate habitat suitability models for capercaillie in the Swiss Alps. The variance explained by the univariate models was found to vary among the predictors and with spatial scale. Within the multivariate models, the best single-scale model (using all predictor variables at the same scale) worked at a scale equivalent to a small annual home range. The multi-scale model, in which each predictor variable was entered at the scale at which it had performed best in the univariate model, did slightly better than the best single-scale model. Our results confirm that habitat variables should be included at different spatial scales when species-habitat relationships are investigated.

Because of limited resources, biodiversity conservation practice is often reduced to measures directed at single species in the hope that this will simultaneously benefit other species in the same community. Such "umbrella species" should therefore have habitat requirements that are similar to those of the other species, whereas their spatial needs should be more extensive. The umbrella-species concept is often applied in management yet rarely tested beforehand. The Capercaillie ( Tetrao urogallus ) is a large forest grouse that is declining over much of its range in Central Europe. It is considered a good example of an umbrella species and is now widely receiving attention from forestry managers. We tested its usefulness as an umbrella species in the Swiss Prealps by analyzing relationships between Capercaillie occurrence and avian biodiversity and asked whether both were associated with the same habitat-structure parameters. Study plots with Capercaillie did not hold significantly higher bird diversity than plots without the grouse. However, the species richness and abundance of birds that are more or less restricted to subalpine forests (mountain birds) and that at the same time are on the red list was considerably higher in Capercaillie plots than in those without Capercaillie. Both Capercaillie and mountain birds responded positively to forest structure characterized by intermediate openness, multistoried tree layer, presence of ecotonal conditions, and abundant cover of ericaceous shrubs. Capercaillie may therefore be a useful umbrella species, at least for that part of avian biodiversity of conservation interest.Capercaillie ( Tetrao urogallus ) y Biodiversidad de Aves: Probando el Concepto de Especie Sombrilla Resumen: Debido a la escasez de recursos, la práctica de la biología de la conservación se reduce a menudo a medidas dirigidas a una sola especie con la esperanza de que esto beneficiará simultáneamente a otras especies de la misma comunidad. Por lo tanto, esas "especies sombrilla" deben tener requerimientos de hábitat similares a los de las otras especies, mientras que sus necesidades espaciales deben ser mayores. El concepto de especie sombrilla se aplica en manejo a menudo, sin embargo rara vez es probado antes. El Capercaillie ( Tetrao urogallus ) es un urogallo que esta declinando en gran parte de su rango en Europa Central. Es considerado un buen ejemplo de una especie sombrilla y esta recibiendo considerable atención de los manejadores de bosques. Probamos su utilidad como especie sombrilla en los Prealpes Suizos analizando relaciones entre la ocurrencia de Capercaillie y la biodiversidad de aves y preguntando si ambos estaban asociados con los mismos parámetros de la estructura del hábitat. Las parcelas de estudio con Capercaillie no presentaron significativamente mayor biodiversidad que las parcelas sin urogallos. Sin embargo, la riqueza y abundancia de especies de aves que están más o menos restringidas a bosques subalpinos (aves de montaña) y, al mismo tiempo, están en la Lista Roja fue c...

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Summary1. Although dung of mammalian herbivores is an important pathway for nutrient return in savanna ecosystems, differences in dung decomposition rates among species have been little studied. 2. We measured the rates of dung deposition and decomposition for various herbivores in a moist Tanzanian savanna and the related differences among species to nutrient concentrations and the activities of soil macrofauna (e.g. different mesh sizes of decomposition bags, or presence and absence of dung beetles). 3. Dung C : N : P stoichiometry varied widely among species, which could in part be explained by differences in feeding strategy (browsers vs. grazers) and digestive physiology (ruminants vs. non-ruminants). Rates of both decomposition and nutrient release were influenced by the C : N : P stoichiometry of dung, with lower relative losses of the least abundant nutrient in the dung. Surprisingly, soil macrofauna increased the relative losses of the least abundant nutrient, thereby stabilizing the ratio of N loss to P loss. Dung beetles increased rates of N and P release from wildebeest dung significantly and also increased N availability in the soil. 4. We conclude that rates of nutrient return in dung depend not only on where herbivores deposit their dung, but also on its C : N : P stoichiometry, the activity of soil macrofauna and interactions between these factors. These factors may therefore influence the relative availabilities of N and P in the soil and hence the functioning of savanna ecosystems.

Habitat selection in ungulates should ensure access to abundant forage of sufficiently high quality. Species living in rugged mountain areas have to face nutritional bottlenecks regularly and should show particularly sophisticated habitat selection behaviour. However, patterns and mechanisms of such adaptations remain little studied. We analysed habitat selection and its seasonal variability of 10 GPS-collared red deer Cervus elaphus living in a topographically challenging landscape of the Swiss Alps. We hypothesised that resource selection by red deer was scale-dependent and predicted that scale-dependence would vary among seasons in relation to seasonal changes of available forage biomass and quality, which we sampled across the entire study area of 250 km 2 . The studied population of Alpine red deer undertook altitudinal migrations and showed scale-dependent habitat selection that was strongest in winter and declined through spring and summer. Selection occurred mostly at the larger (landscape/home-range location) scale and less so at the smaller (within home-range) scale. Topographic parameters were selected mainly at the landscape scale and mostly in winter. About 70% of all instances of preference for habitat parameters were associated with above-average forage characteristics, represented mostly by higher crude protein content, in a few cases also by higher biomass or both. The overall pattern of space use by red deer characterised by migration and seasonal habitat selection was therefore closely linked to the quality of food resources, although some trade-offs with avoiding human disturbance may also have been involved.