33 research outputs found

    Human disturbance is the most limiting factor driving habitat selection of a large carnivore throughout Continental Europe

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    Habitat selection is a multi-scale process driven by trade-offs between benefits, such as resource abundance, and disadvantages, such as the avoidance of risk. The latter includes human disturbances, to which large carnivores, with their large spatial requirements, are especially sensitive. We investigated the ecological processes underlying multi-scale habitat selection of a large carnivore, namely Eurasian lynx, across European landscapes characterized by different levels of human modification. Using a unique dataset of 125 lynx from 9 study sites across Europe, we compared used and available locations within landscape and home-range scales using a novel Mixed Effect randomForest approach, while considering environmental predictors as proxies for human disturbances and environmental resources. At the landscape scale, lynx avoided roads and human settlements, while at the home-range scale natural landscape features associated with shelter and prey abundance were more important. The results showed sex was of relatively low variable importance for lynx's general habitat selection behaviour. We found increasingly homogeneous responses across study sites with finer selection scales, suggesting that study site differences determined coarse selection, while utilization of resources at the finer selection scale was broadly universal. Thereby describing lynx's requirement, if not preference, for heterogeneous forests and shelter from human disturbances and implying that regional differences in coarse-scale selection are driven by availability rather than preference. These results provide crucial information for conserving this species in human-dominated landscapes, as well as for the first time, to our knowledge, generalising habitat selection behaviour of a large carnivore species at a continental scale.acceptedVersio

    Integrating animal tracking datasets at a continental scale for mapping Eurasian lynx habitat

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    Aim: The increasing availability of animal tracking datasets collected across many sites provides new opportunities to move beyond local assessments to enable de-tailed and consistent habitat mapping at biogeographical scales. However, integrating wildlife datasets across large areas and study sites is challenging, as species' varying responses to different environmental contexts must be reconciled. Here, we compare approaches for large-area habitat mapping and assess available habitat for a recolo-nizing large carnivore, the Eurasian lynx (Lynx lynx).Location: Europe.Methods: We use a continental-scale animal tracking database (450 individuals from 14 study sites) to systematically assess modelling approaches, comparing (1) global strategies that pool all data for training versus building local, site-specific models and combining them, (2) different approaches for incorporating regional variation in habi-tat selection and (3) different modelling algorithms, testing nonlinear mixed effects models as well as machine-learning algorithms.Results: Testing models on training sites and simulating model transfers, global and local modelling strategies achieved overall similar predictive performance. Model performance was the highest using flexible machine-learning algorithms and when incorporating variation in habitat selection as a function of environmental variation. Our best-performing model used a weighted combination of local, site-specific habi-tat models. Our habitat maps identified large areas of suitable, but currently unoccu-pied lynx habitat, with many of the most suitable unoccupied areas located in regions that could foster connectivity between currently isolated populations.Main Conclusions: We demonstrate that global and local modelling strategies can achieve robust habitat models at the continental scale and that considering regional variation in habitat selection improves broad-scale habitat mapping. More generally, we highlight the promise of large wildlife tracking databases for large-area habitat mapping. Our maps provide the first high-resolution, yet continental assessment of lynx habitat across Europe, providing a consistent basis for conservation planning for restoring the species within its former range.publishedVersio

    Modelling ranging behaviour of female orang-utans: a case study in Tuanan, Central Kalimantan, Indonesia

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    Quantification of the spatial needs of individuals and populations is vitally important for management and conservation. Geographic information systems (GIS) have recently become important analytical tools in wildlife biology, improving our ability to understand animal movement patterns, especially when very large data sets are collected. This study aims at combining the field of GIS with primatology to model and analyse space-use patterns of wild orang-utans. Home ranges of female orang-utans in the Tuanan Mawas forest reserve in Central Kalimantan, Indonesia were modelled with kernel density estimation methods. Kernel results were compared with minimum convex polygon estimates, and were found to perform better, because they were less sensitive to sample size and produced more reliable estimates. Furthermore, daily travel paths were calculated from 970 complete follow days. Annual ranges for the resident females were approximately 200 ha and remained stable over several years; total home range size was estimated to be 275 ha. On average, each female shared a third of her home range with each neighbouring female. Orang-utan females in Tuanan built their night nest on average 414 m away from the morning nest, whereas average daily travel path length was 777 m. A significant effect of fruit availability on day path length was found. Sexually active females covered longer distances per day and may also temporarily expand their ranges

    Carrion Availability in Space and Time

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    Introduction Availability of carrion to scavengers is a central issue in carrion ecology and management, and is crucial for understanding the evolution of scavenging behaviour. Compared to live animals, their carcasses are relatively unpredictable in space and time in natural conditions, with a few exceptions (see below, especially Sect. “Carrion Exchange at the Terrestrial-Aquatic Interface”). Carrion is also an ephemeral food resource due to the action of a plethora of consumers, from microorganisms to large vertebrates, as well as to desiccation (i.e., loss of water content; DeVault et al. 2003; Beasley et al. 2012; Barton et al. 2013; Moleón et al. 2014). With a focus on vertebrate carcasses, here we give an overview of (a) the causes that produce carrion, (b) the rate of carrion production, (c) the factors affecting carrion quality, and (d) the distribution of carrion in space and time, both in terrestrial and aquatic environments (including their interface). In this chapter, we will focus on naturally produced carrion, whereas non-natural causes of animal mortality are described in chapter “Human-Mediated Carrion: Effects on Ecological Processes”. However, throughout this chapter we also refer to extensive livestock carrion, because in the absence of strong restrictions such as those imposed in the European Community after the bovine spongiform encephalopathy crisis (Donázar et al. 2009; Margalida et al. 2010), the spatiotemporal availability of carrion of extensive livestock and wild ungulates is similar

    Linx individual B132

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    Context-dependent behaviour and connectivity of recolonizing brown bear populations identify transboundary conservation challenges in Central Europe

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    Following historical restrictions to isolated and patchy populations, large carnivores like the brown bear Ursus arctos are recolonizing areas of their historical range in Europe. This process is of particular interest in the Alps and the Dinaric Mountains in Central Europe, the largest mountain range in the continent and of transboundary conservation interest. To assist policies focused on the expansion of bears in this region, we conducted habitat selection analyses accounting for different behaviour between three populations (Trentino, pre-Alps and Dinaric) where bears have adapted to different intensities of human persecution. We then identified the landscape connectivity between these fragmented populations that could provide viable habitat and stepping-stone patches for recolonization. To handle individual and population differences in space-use, we modelled habitat selection per population from an individual-level and integrated results into a multi-population model using scale-integrated resource selection functions. We then calculated connectivity indices per patch and the contribution of various countries involved in bear management in the region to enhancing connectivity. Bears mostly selected forests across all populations while preferences for other variables differed among populations and across scales. Bears in the highly humanized habitats of the Trentino selected the most intricate topography, where they could more easily find refuge. Suitable but fragmented habitat patches were common all over the study area with the most suitable habitat in the pre-Alpine and Dinaric populations. However, the Trentino and pre-Alp included the patches of maximum/medium priority as stepping-stones to connect these populations. Transboundary initiatives for the conservation of existing habitat and the facilitation of connectivity are required to promote current bear expansion and reduce conflicts with humans. Our framework provides insight into the adaptive behaviour of large carnivores in human-dominated landscapes in a conservation context

    Status of the Eurasian lynx (Lynx lynx) in the Italian Alps: an overview 2000-2004

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    To assess the status of lynx we analysed lynx signs of presence within the Italian Alps from 2000\u20132004. A total of 411 signs of lynx presence have been collected, compared to 261 signs during the previous pentad. Lynx tracks were the most frequent sign of presence, followed by prey remains and direct observations. Livestock depredation has so far not been a problem in Italy. Most of the presence signs (84%) are still concentrated in the Eastern Italian Alps in Friuli V.G. and the province of Belluno. A few confi rmed lynx signs of presence indicate a recolonisation of the Trentino Alto Adige region. In the western Alps (Piemonte region), most signs of lynx presence are concentrated close to the French border. The number of lynx occurring in Italy is roughly estimated to less than 20 individuals. The population cannot be considered viable and is still depending on immigration from neighboring countries. Keywords: Lynx lynx, Italy, monitoring, status, Alp

    ABS 1 - 2006.indd

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    Abstract: To assess the status of lynx we analysed lynx signs of presence within the Italian Alps from [2000][2001][2002][2003][2004]. A total of 411 signs of lynx presence have been collected, compared to 261 signs during the previous pentad. Lynx tracks were the most frequent sign of presence, followed by prey remains and direct observations. Livestock depredation has so far not been a problem in Italy. Most of the presence signs (84%) are still concentrated in the Eastern Italian Alps in Friuli V.G. and the province of Belluno. A few confirmed lynx signs of presence indicate a recolonisation of the Trentino Alto Adige region. In the western Alps (Piemonte region), most signs of lynx presence are concentrated close to the French border. The number of lynx occurring in Italy is roughly estimated to less than 20 individuals. The population cannot be considered viable and is still depending on immigration from neighbouring countries. Abstract. To assess the status of lynx we analysed lynx signs of presence within the Italian Alps from [2000][2001][2002][2003][2004]. A total of 411 signs of lynx presence have been collected, compared to 261 signs during the previous pentad. Lynx tracks were the most frequent sign of presence, followed by prey remains and direct observations. Livestock depredation has so far not been a problem in Italy. Most of the presence signs (84%) are still concentrated in the Eastern Italian Alps in Friuli V.G. and the province of Belluno. A few confi rmed lynx signs of presence indicate a recolonisation of the Trentino Alto Adige region. In the western Alps (Piemonte region), most signs of lynx presence are concentrated close to the French border. The number of lynx occurring in Italy is roughly estimated to less than 20 individuals. The population cannot be considered viable and is still depending on immigration from neighboring countries. 13 ACT
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