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Hunting and its impacts on wildlife are typically studied regionally, with a particular focus on the Global South. Hunting can, however, also undermine rewilding efforts or threaten wildlife in the Global North. Little is known about how hunting manifests under varying socioeconomic and ecological contexts across the Global South and North. Herein, we examined differences and commonalities in hunting characteristics across an exemplary Global South-North gradient approximated by the Human Development Index (HDI) using face-to-face interviews with 114 protected area (PA) managers in 25 African and European countries. Generally, we observed that hunting ranges from the illegal, economically motivated, and unsustainable hunting of herbivores in the South to the legal, socially and ecologically motivated hunting of ungulates within parks and the illegal hunting of mainly predators outside parks in the North. Commonalities across this Africa-Europe South-North gradient included increased conflict-related killings in human-dominated landscapes and decreased illegal hunting with beneficial community conditions, such as mutual trust resulting from community involvement in PA management. Nevertheless, local conditions cannot outweigh the strong effect of the HDI on unsustainable hunting. Our findings highlight regional challenges that require collaborative, integrative efforts in wildlife conservation across actors, while identified commonalities may outline universal mechanisms for achieving this goal.
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Animales Salvajes , Conservación de los Recursos Naturales , África , Animales , Europa (Continente) , Humanos , Caza , MamíferosRESUMEN
The increasing popularity of digital media among protected area visitors poses challenges to protected area management. It alters the way visitors move and behave in the area, potentially increasing disturbance of nature, and it might also affect their expectation prior to the visit and their reflection on it. Simultaneously, digital media allow protected area managers to develop and implement new methods of digital visitor management (DVM). This may help to avoid conflicts and ensure compliance with rules and regulations and may have much further reaching positive consequences. Based on an online survey across 131 parks in 46 countries covering all continents, this study examined for the first time how protected areas view DVM. The results showed that the majority of park managers see digitalization as an opportunity, with 91% agreeing that it enables them to reach larger numbers of visitors and to provide real-time information. The advantage of integrating digital media into visitor monitoring was recognized. However, some park managers perceived digitalization as problematic, with 42% agreeing that it increases visitor load in sensitive areas and 40% agreeing that it leads to more off-trail activity. A clear majority of the respondents (61-91%) saw the proposed methods of DVM as effective or very effective. Accordingly, 70% of them envisioned using DVM in the future. Our findings suggest that the effects of digitalization in outdoor recreation are largely similar across the globe, with no significant influence of economic status or region. They offer insights into the potential of DVM for protected area management, but also its main obstacles. Adoption will be facilitated by increasing staff and funding for DVM. Additionally, knowledge exchange between protected areas can ease the successful implementation of new digital tools.
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Conservación de los Recursos Naturales , Recreación , Humanos , Conservación de los Recursos Naturales/métodos , Internet , Conocimiento , Encuestas y CuestionariosRESUMEN
Vertebrate scavengers provide essential ecosystem services such as accelerating carrion decomposition by consuming carcasses, exposing tissues to microbial and invertebrate decomposers, and recycling nutrients back into the ecosystem. Some scavengers do not consume carcasses on site but rather scatter their remains in the surroundings, which might have important implications for nutrient transport, forensic investigations and the spread of diseases such as African Swine Fever. However, only a few studies have investigated and measured the scatter distances. Using wild boar (Sus scrofa) carcasses and limbs, we monitored scavenging behavior and measured scatter distances of mammals. We placed 20 carcasses (up to 25 kg) and 21 separate limbs equipped with very high frequency (VHF) transmitters and monitored scavenger activity using camera traps in a mountainous region in southeast Germany. Except for one carcass, all other carcasses and limbs were scattered. We measured 72 scatter distances (of 89 scattering events; mean = 232 m, maximum = 1250 m), of which 75% were dispersed up to 407 m. Scavengers moved scattered pieces into denser vegetation compared to the half-open vegetation at provisioning sites. Red foxes (Vulpes vulpes) were the most common scavenger species, contributing to 72 scattering events (58 measured scatter distances). Our results provide evidence of scatter distances farther than previously assumed and have far-reaching implications for disease management or forensic investigations, as the broader surroundings of carcasses must be included in search efforts to remove infectious material or relevant body parts for forensic analysis.
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Sus scrofa , Animales , Porcinos , Ecosistema , Fiebre Porcina Africana , Alemania , ZorrosRESUMEN
Old-growth forests are essential to preserve biodiversity and play an important role in sequestering carbon and mitigating climate change. However, their existence across Europe is vulnerable due to the scarcity of their distribution, logging, and environmental threats. Therefore, providing the current status of old-growth forests across Europe is essential to aiding informed conservation efforts and sustainable forest management. Remote sensing techniques have proven effective for mapping and monitoring forests over large areas. However, relying solely on remote sensing spectral or structural information cannot capture comprehensive horizontal and vertical structure complexity profiles associated with old-growth forest characteristics. To overcome this issue, we combined spectral information from Sentinel-2A multispectral imagery with 3D structural information from high-density point clouds of airborne laser scanning (ALS) imagery to map old-growth forests over an extended area. Four features from the ALS data and fifteen from Sentinel-2A comprising raw band (spectral reflectance), vegetation indices (VIs), and texture were selected to create three datasets used in the classification process using the random forest algorithm. The results demonstrated that combining ALS and Sentinel-2A features improved the classification performance and yielded the highest accuracy for old-growth class, with an F1-score of 92% and producer's and user's accuracies of 93% and 90%, respectively. The findings suggest that features from ALS and Sentinel-2A data sensitive to forest structure are essential for identifying old-growth forests. Integrating open-access satellite imageries, such as Sentinel-2A and ALS data, can benefit forest managers, stakeholders, and conservationists in monitoring old-growth forest preservation across a broader spatial extent.
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Monitoreo del Ambiente , Bosques , Tecnología de Sensores Remotos , Monitoreo del Ambiente/métodos , Europa (Continente) , Conservación de los Recursos Naturales/métodos , Biodiversidad , Imágenes Satelitales , Cambio Climático , Rayos LáserRESUMEN
Human activity and associated landscape modifications alter the movements of animals with consequences for populations and ecosystems worldwide. Species performing long-distance movements are thought to be particularly sensitive to human impact. Despite the increasing anthropogenic pressure, it remains challenging to understand and predict animals' responses to human activity. Here we address this knowledge gap using 1206 Global Positioning System movement trajectories of 815 individuals from 14 red deer (Cervus elaphus) and 14 elk (Cervus canadensis) populations spanning wide environmental gradients, namely the latitudinal range from the Alps to Scandinavia in Europe, and the Greater Yellowstone Ecosystem in North America. We measured individual-level movements relative to the environmental context, or movement expression, using the standardized metric Intensity of Use, reflecting both the directionality and extent of movements. We expected movement expression to be affected by resource (Normalized Difference Vegetation Index, NDVI) predictability and topography, but those factors to be superseded by human impact. Red deer and elk movement expression varied along a continuum, from highly segmented trajectories over relatively small areas (high intensity of use), to directed transitions through restricted corridors (low intensity of use). Human activity (Human Footprint Index, HFI) was the strongest driver of movement expression, with a steep increase in Intensity of Use as HFI increased, but only until a threshold was reached. After exceeding this level of impact, the Intensity of Use remained unchanged. These results indicate the overall sensitivity of Cervus movement expression to human activity and suggest a limitation of plastic responses under high human pressure, despite the species also occurring in human-dominated landscapes. Our work represents the first comparison of metric-based movement expression across widely distributed populations of a deer genus, contributing to the understanding and prediction of animals' responses to human activity.
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Ciervos , Ecosistema , Humanos , Animales , Ciervos/fisiología , Actividades Humanas , América del Norte , Sistemas de Información GeográficaRESUMEN
Kill rates are a central parameter to assess the impact of predation on prey species. An accurate estimation of kill rates requires a correct identification of kill sites, often achieved by field-checking GPS location clusters (GLCs). However, there are potential sources of error included in kill-site identification, such as failing to detect GLCs that are kill sites, and misclassifying the generated GLCs (e.g., kill for nonkill) that were not field checked. Here, we address these two sources of error using a large GPS dataset of collared Eurasian lynx (Lynx lynx), an apex predator of conservation concern in Europe, in three multiprey systems, with different combinations of wild, semidomestic, and domestic prey. We first used a subsampling approach to investigate how different GPS-fix schedules affected the detection of GLC-indicated kill sites. Then, we evaluated the potential of the random forest algorithm to classify GLCs as nonkills, small prey kills, and ungulate kills. We show that the number of fixes can be reduced from seven to three fixes per night without missing more than 5% of the ungulate kills, in a system composed of wild prey. Reducing the number of fixes per 24 h decreased the probability of detecting GLCs connected with kill sites, particularly those of semidomestic or domestic prey, and small prey. Random forest successfully predicted between 73%-90% of ungulate kills, but failed to classify most small prey in all systems, with sensitivity (true positive rate) lower than 65%. Additionally, removing domestic prey improved the algorithm's overall accuracy. We provide a set of recommendations for studies focusing on kill-site detection that can be considered for other large carnivore species in addition to the Eurasian lynx. We recommend caution when working in systems including domestic prey, as the odds of underestimating kill rates are higher.
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Carnívoros , Lynx , Animales , Europa (Continente) , Conducta Predatoria , ProbabilidadRESUMEN
Visibility (viewshed) plays a significant and diverse role in animals' behaviour and fitness. Understanding how visibility influences animal behaviour requires the measurement of habitat visibility at spatial scales commensurate to individual animal choices. However, measuring habitat visibility at a fine spatial scale over a landscape is a challenge, particularly in highly heterogeneous landscapes (e.g. forests). As a result, our ability to model the influence of fine-scale visibility on animal behaviour has been impeded or limited. In this study, we demonstrate the application of the concept of three-dimensional (3D) cumulative viewshed in the study of animal spatial behaviour at a landscape level. Specifically, we employed a newly described approach that combines terrestrial and airborne light detection and ranging (LiDAR) to measure fine-scale habitat visibility (3D cumulative viewshed) on a continuous scale in forested landscapes. We applied the LiDAR-derived visibility to investigate how visibility in forests affects the summer habitat selection and the movement of 20 GPS-collared female red deer Cervus elaphus in a temperate forest in Germany. We used integrated step selection analysis to determine whether red deer show any preference for fine-scale habitat visibility and whether visibility is related to the rate of movement of red deer. We found that red deer selected intermediate habitat visibility. Their preferred level of visibility during the day was substantially lower than that of night and twilight, whereas the preference was not significantly different between night and twilight. In addition, red deer moved faster in high-visibility areas, possibly mainly to avoid predation and anthropogenic risk. Furthermore, red deer moved most rapidly between locations in the twilight. For the first time, the preference for intermediate habitat visibility and the adaption of movement rate to fine-scale visibility by a forest-dwelling ungulate species at a landscape scale was revealed. The LiDAR technique used in this study offers fine-scale habitat visibility at the landscape level in forest ecosystems, which would be of broader interest in the fields of animal ecology and behaviour.
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Ciervos , Ecosistema , Animales , Femenino , Bosques , Conducta Animal , MovimientoRESUMEN
Research on decomposer communities has traditionally focused on plant litter or deadwood. Even though carrion forms highly nutrient-rich necromass that enhance ecosystem heterogeneity, the factors influencing saprophytic communities remain largely unknown. For deadwood, experiments have shown that different drivers determine beetles (i.e., decay stage, microclimate, and space), fungi (i.e., decay stage and tree species) and bacteria (decay stage only) assemblages. To test the hypothesis that similar factors also structure carrion communities, we sampled 29 carcasses exposed for 30 days that included Cervus elaphus (N = 6), Capreolus capreolus (N = 18), and Vulpes vulpes (N = 5) in a mountain forest throughout decomposition. Beetles were collected with pitfall traps, while microbial communities were characterized using amplicon sequencing. Assemblages were determined with a focus from rare to dominant species using Hill numbers. With increasing focus on dominant species, the relative importance of carcass identity on beetles and space on bacteria increased, while only succession and microclimate remained relevant for fungi. For beetle and bacteria with focus on dominant species, host identity was more important than microclimate, which is in marked contrast to deadwood. We conclude that factors influencing carrion saprophytic assemblages show some consistency, but also differences from those of deadwood assemblages, suggesting that short-lived carrion and long-lasting deadwood both provide a resource pulse with different adaptions in insects and microbes. As with deadwood, a high diversity of carcass species under multiple decay stages and different microclimates support a diverse decomposer community.
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Escarabajos , Ecosistema , Animales , Biodiversidad , Bosques , Insectos , HongosRESUMEN
Wildlife can perceive humans as predators and human disturbance, whether lethal (e.g., hunting) or non-lethal (e.g., hiking, biking, and skiing), triggers antipredator behavior among prey. Visibility is the property that relates habitat structure to accessibility of visual information that allows animals to detect predators and evaluate predation risk. Thus, the visibility of a habitat (hereafter referred to as habitat visibility) for prey species alters the perceived risk of predation and therefore has a strong influence on their antipredator behavior. Yet, knowledge of how habitat visibility affects the response of animals to different types of human disturbance is limited, partly, because it is challenging to measure habitat visibility for animals at a fine spatial scale over a landscape, particularly in highly heterogeneous landscapes (e.g., forests). In this study, we employed a newly described approach that combines terrestrial and airborne LiDAR to contiguously measure fine-scale habitat visibility in a forested landscape. We applied the LiDAR-derived habitat visibility to examine how habitat visibility in forests affects the summer space use of 20 GPS-collared female red deer (Cervus elaphus) modeled with integrated step-selection functions in the Bavarian Forest National Park, Germany when exposed to various types of human disturbance including recreational activities, forest roads, hiking trails, and hunting. We found that red deer in our study area avoided areas with higher all types of human disturbance, especially during daylight hours. Furthermore, habitat visibility significantly modified the use of space by red deer in response to human recreational activities, forest roads, and hiking trails, but not to the hunting area. Red deer tended to tolerate a higher intensity of human recreational activities and to use areas closer to forest roads or hiking trails when they have lower habitat visibility (i.e., more cover). Our findings highlight the importance of considering visual perception when studying the response of wild animals to human disturbance. We emphasize the potential to mitigate negative consequences of human disturbance on wildlife, through measures such as maintaining vegetative buffers around recreational infrastructure (e.g., roads and skiing tracks) in order to reduce habitat visibility around areas frequented by humans.
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Ciervos , Herbivoria , Humanos , Animales , Femenino , Ciervos/fisiología , Ecosistema , Bosques , Conducta Predatoria , Animales SalvajesRESUMEN
Aim: Macroecological studies that require habitat suitability data for many species often derive this information from expert opinion. However, expert-based information is inherently subjective and thus prone to errors. The increasing availability of GPS tracking data offers opportunities to evaluate and supplement expert-based information with detailed empirical evidence. Here, we compared expert-based habitat suitability information from the International Union for Conservation of Nature (IUCN) with habitat suitability information derived from GPS-tracking data of 1,498 individuals from 49 mammal species. Location: Worldwide. Time period: 1998-2021. Major taxa studied: Forty-nine terrestrial mammal species. Methods: Using GPS data, we estimated two measures of habitat suitability for each individual animal: proportional habitat use (proportion of GPS locations within a habitat type), and selection ratio (habitat use relative to its availability). For each individual we then evaluated whether the GPS-based habitat suitability measures were in agreement with the IUCN data. To that end, we calculated the probability that the ranking of empirical habitat suitability measures was in agreement with IUCN's classification into suitable, marginal and unsuitable habitat types. Results: IUCN habitat suitability data were in accordance with the GPS data (> 95% probability of agreement) for 33 out of 49 species based on proportional habitat use estimates and for 25 out of 49 species based on selection ratios. In addition, 37 and 34 species had a > 50% probability of agreement based on proportional habitat use and selection ratios, respectively. Main conclusions: We show how GPS-tracking data can be used to evaluate IUCN habitat suitability data. Our findings indicate that for the majority of species included in this study, it is appropriate to use IUCN habitat suitability data in macroecological studies. Furthermore, we show that GPS-tracking data can be used to identify and prioritize species and habitat types for re-evaluation of IUCN habitat suitability data.
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Conservation grazing uses semi-feral or domesticated herbivores to limit encroachment in open areas and to promote biodiversity. However, we are still unaware of its effects on wild herbivores. This study investigates the influence of herded sheep and goats on red deer (Cervus elaphus) spatial behavior by testing three a-priori hypotheses: (i) red deer are expected to avoid areas used by livestock, as well as adjacent areas, when livestock are present, albeit (ii) red deer increase the use of these areas when sheep and goats are temporarily absent and (iii) there is a time-lagged disruption in red deer spatial behavior when conservation grazing practice ends. Using GPS-telemetry data on red deer from a German heathland area, we modelled their use of areas grazed by sheep and goats, using mixed-effect logistic regression. Additionally, we developed seasonal resource selection functions (use-availability design) to depict habitat selection by red deer before, during, and after conservation grazing. Red deer used areas less during conservation grazing throughout all times of the day and there was no compensatory use during nighttime. This effect mostly persisted within 21 days after conservation grazing. Effects on habitat selection of red deer were detectable up to 3000 meters away from the conservation grazing sites, with no signs of either habituation or adaption. For the first time, we demonstrate that conservation grazing can affect the spatio-temporal behavior of wild herbivores. Our findings are relevant for optimizing landscape and wildlife management when conservation grazing is used in areas where wild herbivores are present.
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Ciervos , Animales , Biodiversidad , Conservación de los Recursos Naturales , Ecosistema , Cabras , Herbivoria , Ovinos , Conducta EspacialRESUMEN
Disturbances play a key role in driving forest ecosystem dynamics, but how disturbances shape wildlife habitat across space and time often remains unclear. A major reason for this is a lack of information about changes in habitat suitability across large areas and longer time periods. Here, we use a novel approach based on Landsat satellite image time series to map seasonal habitat suitability annually from 1986 to 2017. Our approach involves characterizing forest disturbance dynamics using Landsat-based metrics, harmonizing these metrics through a temporal segmentation algorithm, and then using them together with GPS telemetry data in habitat models. We apply this framework to assess how natural forest disturbances and post-disturbance salvage logging affect habitat suitability for two ungulates, roe deer (Capreolus capreolus) and red deer (Cervus elaphus), over 32 yr in a Central European forest landscape. We found that red and roe deer differed in their response to forest disturbances. Habitat suitability for red deer consistently improved after disturbances, whereas the suitability of disturbed sites was more variable for roe deer depending on season (lower during winter than summer) and disturbance agent (lower in windthrow vs. bark-beetle-affected stands). Salvage logging altered the suitability of bark beetle-affected stands for deer, having negative effects on red deer and mixed effects on roe deer, but generally did not have clear effects on habitat suitability in windthrows. Our results highlight long-lasting legacy effects of forest disturbances on deer habitat. For example, bark beetle disturbances improved red deer habitat suitability for at least 25 yr. The duration of disturbance impacts generally increased with elevation. Methodologically, our approach proved effective for improving the robustness of habitat reconstructions from Landsat time series: integrating multiyear telemetry data into single, multi-temporal habitat models improved model transferability in time. Likewise, temporally segmenting the Landsat-based metrics increased the temporal consistency of our habitat suitability maps. As the frequency of natural forest disturbances is increasing across the globe, their impacts on wildlife habitat should be considered in wildlife and forest management. Our approach offers a widely applicable method for monitoring habitat suitability changes caused by landscape dynamics such as forest disturbance.
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Ciervos , Ecosistema , Animales , Animales Salvajes , Bosques , Estaciones del AñoRESUMEN
Hopkins' Bioclimatic Law predicts geographical patterns in phenological timing by establishing a correspondence between latitudinal and altitudinal gradients. First proposed for key phenological events of plants, such as leaf sprouting or flowering dates, this law has rarely been used to assess the geographical equivalence of key life-history traits of mammals. We hypothesize that (H1) parturition dates of European roe deer Capreolus capreolus are delayed and more synchronized at higher latitudes and altitudes, (H2) parturition timing varies along latitudinal and altitudinal gradients in a way that matches the Hopkins' Bioclimatic Law and (H3) females adjust parturition timing to match the period of high energy demand with peak resource availability. We used parturition dates of 7,444 European roe deer from Switzerland to assess altitudinal variation in birth timing and synchrony from 288 to 2,366 m a.s.l. We then performed a literature survey to compare altitudinal results with those from different populations along the species' latitudinal range of distribution. Finally, we performed spatial analysis combining our highly resolved altitudinal data on parturition dates with plant phenology data. As expected, parturition dates were delayed with increasing latitude and altitude. This delay matched the Bioclimatic Law, as the effect of 1º increase in latitude was similar to 120 m increase in altitude. However, while parturitions were more synchronized with increasing altitude, we did not detect any trend along the latitudinal gradient. Finally, plant phenology explained altitudinal variation in parturition timing better than a linear effect of altitude. Our findings clearly demonstrate the ability of a large herbivore to match parturition timing with phenological conditions across the altitudinal gradient, even at the smallest spatial scales.
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Ciervos , Herbivoria , Altitud , Animales , Cambio Climático , Femenino , Parto , Embarazo , SuizaRESUMEN
Humans, as super predators, can have strong effects on wildlife behaviour, including profound modifications of diel activity patterns. Subsequent to the return of large carnivores to human-modified ecosystems, many prey species have adjusted their spatial behaviour to the contrasting landscapes of fear generated by both their natural predators and anthropogenic pressures. The effects of predation risk on temporal shifts in diel activity of prey, however, remain largely unexplored in human-dominated landscapes. We investigated the influence of the density of lynx Lynx lynx, a nocturnal predator, on the diel activity patterns of their main prey, the roe deer Capreolus capreolus, across a gradient of human disturbance and hunting at the European scale. Based on 11 million activity records from 431 individually GPS-monitored roe deer in 12 populations within the EURODEER network (http://eurodeer.org), we investigated how lynx predation risk in combination with both lethal and non-lethal human activities affected the diurnality of deer. We demonstrated marked plasticity in roe deer diel activity patterns in response to spatio-temporal variations in risk, mostly due to human activities. In particular, roe deer decreased their level of diurnality by a factor of 1.37 when the background level of general human disturbance was high. Hunting exacerbated this effect, as during the hunting season deer switched most of their activity to night-time and, to a lesser extent, to dawn, although this pattern varied noticeably in relation to lynx density. Indeed, in the presence of lynx, their main natural predator, roe deer were relatively more diurnal. Overall, our results revealed a strong influence of human activities and the presence of lynx on diel shifts in roe deer activity. In the context of the recovery of large carnivores across Europe, we provide important insights about the effects of predators on the behavioural responses of their prey in human-dominated ecosystems. Modifications in the temporal partitioning of ungulate activity as a response to human activities may facilitate human-wildlife coexistence, but likely also have knock-on effects for predator-prey interactions, with cascading effects on ecosystem functioning.
Résumé Les humains, en tant que 'super-prédateurs', peuvent avoir des effets importants sur le comportement de la faune sauvage, y compris des modifications profondes de leurs rythmes circadiens d'activité. A la suite du retour des grands carnivores dans les écosystèmes anthropisés, de nombreuses espèces proies ont ajusté leur comportement spatial à ces paysages de la peur contrastés, générés à la fois par les pressions liées aux risques anthropiques et à la présence de leurs prédateurs naturels. Les effets du risque de prédation sur les modifications temporelles des rythmes circadiens d'activité des proies restent cependant largement inconnus dans les écosystèmes dominés par l'homme. Ici, nous avons étudié l'influence de la densité de lynx Lynx lynx, un prédateur nocturne, sur les rythmes circadiens d'activité de leur proie principale, le chevreuil Capreolus capreolus, à travers un gradient de pressions anthropiques à l'échelle Européenne. Sur la base de plus de 11 million de données d'activité issues de 431 suivis individuels de chevreuils équipés de colliers GPS provenant de 12 populations au sein du réseau EURODEER (http://eurodeer.org), nous avons analysé comment le risque de prédation par le lynx, associé aux risques létaux et non-létaux des activités humaines, influence la diurnalité des chevreuils. Nous avons démontré une forte plasticité des rythmes circadiens d'activité des chevreuils en réponse aux variations spatio-temporelles du risque, et notamment face aux activités humaines. Plus particulièrement, les chevreuils diminuent leur degré de diurnalité d'un facteur de 1.37 lorsque le dérangement humain est important. La chasse accentue cet effet, puisque durant la saison de chasse les chevreuils basculent la plupart de leur activité de nuit, et dans une moindre mesure, durant l'aube également, bien que ce patron soit essentiellement variable en fonction de la densité de lynx. En effet, en présence de lynx, leur principal prédateur, les chevreuils sont relativement plus diurnes. Globalement, nos résultats révèlent une forte influence des activités humaines et de la présence de lynx sur l'ajustement des rythmes circadiens d'activité des chevreuils. Dans le contexte du retour des grands carnivores en Europe, notre étude apporte de nouvelles connaissances sur les effets des prédateurs sur la réponse comportementale de leur proie dans des écosystèmes anthropisés. La modification de la répartition temporelle de l'activité des ongulés en réponse aux activités humaines pourrait être un facteur facilitant la coexistence homme-faune sauvage, avec toutefois des conséquences autres sur les interactions prédateurs-proies et leurs effets en cascade sur le fonctionnement des écosystèmes.
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Ciervos , Lynx , Animales , Ecosistema , Europa (Continente) , Miedo , Humanos , Conducta PredatoriaRESUMEN
Restricting movements to familiar areas should increase individual fitness as it provides animals with information about the spatial distribution of resources and predation risk. While the benefits of familiarity for locating resources have been reported previously, the potential value of familiarity for predation avoidance has been accorded less attention. It has been suggested that familiarity should be beneficial for anti-predator behaviour when direct cues of predation risk are unclear and do not allow prey to identify well-defined spatial refuges. However, to our knowledge, this hypothesis has yet to be tested. Here, we assessed how site familiarity, measured as the intensity of use of a given location, is associated with the probability of roe deer Capreolus capreolus being killed by two predators with contrasting hunting tactics, the Eurasian lynx Lynx lynx and human hunters. While risk of human hunting was confined to open habitats, risk of lynx predation was more diffuse, with no clear refuge areas. We estimated cause-specific mortality rates in a competing risk framework for 212 GPS-collared roe deer in two ecologically distinct areas of Central Europe to test the hypothesis that the daily risk of being killed by lynx or hunters should be lower in areas of high familiarity. We found strong evidence that site familiarity reduces the risk of being predated by lynx, whereas the evidence that the risk of being hunted is linked to site familiarity was weak. We suggest that local knowledge about small-scale differences in predation risk and information about efficient escape routes affect an individual's ability to avoid or escape an attack by an ambush predator. Our study emphasizes the role of site familiarity in determining the susceptibility of prey to predation. Further research will be required to understand better how a cognitive map of individual spatial information is beneficial for avoiding predation in the arms race that drives the predator-prey shell game.
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Ciervos , Lynx , Animales , Ecosistema , Europa (Continente) , Herbivoria , Conducta PredatoriaRESUMEN
1. Primary objectives of national parks usually include both, the protection of natural processes and species conservation. When these objectives conflict, as occurs because of the cascading effects of large mammals (i.e., ungulates and large carnivores) on lower trophic levels, park managers have to decide upon the appropriate management while considering various local circumstances. 2. To analyse if ungulate management strategies are in accordance with the objectives defined for protected areas, we assessed the current status of ungulate management across European national parks using the naturalness concept and identified the variables that influence the management. 3. We collected data on ungulate management from 209 European national parks in 29 countries by means of a large-scale questionnaire survey. Ungulate management in the parks was compared by creating two naturalness scores. The first score reflects ungulate and large carnivore species compositions, and the second evaluates human intervention on ungulate populations. We then tested whether the two naturalness score categories are influenced by the management objectives, park size, years since establishment, percentage of government-owned land, and human impact on the environment (human influence index) using two generalized additive mixed models. 4. In 67.9% of the national parks, wildlife is regulated by culling (40.2%) or hunting (10.5%) or both (17.2%). Artificial feeding occurred in 81.3% of the national parks and only 28.5% of the national parks had a non-intervention zone covering at least 75% of the area. Furthermore, ungulate management differed greatly among the different countries, likely because of differences in hunting traditions and cultural and political backgrounds. Ungulate management was also influenced by park size, human impact on the landscape, and national park objectives, but after removing these variables from the full model the reduced models only showed a small change in the deviance explained. In areas with higher anthropogenic pressure, wildlife diversity tended to be lower and a higher number of domesticated species tended to be present. Human intervention (culling and artificial feeding) was lower in smaller national parks and when park objectives followed those set by the International Union for the Conservation of Nature (IUCN). 5. Our study shows that many European national parks do not fulfil the aims of protected area management as set by IUCN guidelines. In contrast to the USA and Canada, Europe currently has no common ungulate management policy within national parks. This lack of a common policy together with differences in species composition, hunting traditions, and cultural or political context has led to differences in ungulate management among European countries. To fulfil the aims and objectives of national parks and to develop ungulate management strategies further, we highlight the importance of creating a more integrated European ungulate management policy to meet the aims of national parks.
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Conservación de los Recursos Naturales , Parques Recreativos , Animales , Canadá , Europa (Continente) , Humanos , MamíferosRESUMEN
Much research on large herbivore movement has focused on the annual scale to distinguish between resident and migratory tactics, commonly assuming that individuals are sedentary at the within-season scale. However, apparently sedentary animals may occupy a number of sub-seasonal functional home ranges (sfHR), particularly when the environment is spatially heterogeneous and/or temporally unpredictable. The roe deer (Capreolus capreolus) experiences sharply contrasting environmental conditions due to its widespread distribution, but appears markedly sedentary over much of its range. Using GPS monitoring from 15 populations across Europe, we evaluated the propensity of this large herbivore to be truly sedentary at the seasonal scale in relation to variation in environmental conditions. We studied movement using net square displacement to identify the possible use of sfHR. We expected that roe deer should be less sedentary within seasons in heterogeneous and unpredictable environments, while migratory individuals should be seasonally more sedentary than residents. Our analyses revealed that, across the 15 populations, all individuals adopted a multi-range tactic, occupying between two and nine sfHR during a given season. In addition, we showed that (i) the number of sfHR was only marginally influenced by variation in resource distribution, but decreased with increasing sfHR size; and (ii) the distance between sfHR increased with increasing heterogeneity and predictability in resource distribution, as well as with increasing sfHR size. We suggest that the multi-range tactic is likely widespread among large herbivores, allowing animals to track spatio-temporal variation in resource distribution and, thereby, to cope with changes in their local environment.
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Ciervos , Herbivoria , Animales , Europa (Continente) , Fenómenos de Retorno al Lugar Habitual , Estaciones del AñoRESUMEN
Boreal and mountainous forests are a primary focus of conservation efforts and are naturally prone to large-scale disturbances, such as outbreaks of bark beetles. Affected stands are characterised by biological legacies which persist through the disturbance and subsequent succession. The lack of long-term monitoring data on post-disturbance forest structure precludes understanding of the complex pathways by which natural disturbances affect forest structure and subsequently species presence. We analysed the response of capercaillie (Tetrao urogallus) and hazel grouse (Tetrastes bonasia) to bark beetle infestations. We combined high-resolution airborne light detection and ranging (LiDAR) with a 23-year time series of aerial photography to quantify present-day forest structure and stand disturbance history. Species presence was assessed by collecting droppings of hazel grouse and capercaillie in a citizen science project. Structural equation models showed that the probability of hazel grouse presence increased with increasing disturbance, and the probability of both hazel grouse and capercaillie presence increased with succession. Indirect effects of bark beetle infestations, such as a reduced abundance of deciduous trees and an enhanced herb layer cover, were positively associated with capercaillie presence. Decreasing canopy cover increased the probability of hazel grouse presence. The high temporal and spatial heterogeneity of bark beetle infestations created forest structures that meet the contrasting habitat requirements of both, capercaillie and hazel grouse. This heterogeneity resulted from biological legacies such as decomposing snags, and the simultaneous regrowth of natural regeneration. A benign-neglect strategy towards bark beetle infestations could hence foster capercaillie and hazel grouse in mountainous forests.
RESUMEN
The habitat-amount hypothesis challenges traditional concepts that explain species richness within habitats, such as the habitat-patch hypothesis, where species number is a function of patch size and patch isolation. It posits that effects of patch size and patch isolation are driven by effects of sample area, and thus that the number of species at a site is basically a function of the total habitat amount surrounding this site. We tested the habitat-amount hypothesis for saproxylic beetles and their habitat of dead wood by using an experiment comprising 190 plots with manipulated patch sizes situated in a forested region with a high variation in habitat amount (i.e., density of dead trees in the surrounding landscape). Although dead wood is a spatio-temporally dynamic habitat, saproxylic insects have life cycles shorter than the time needed for habitat turnover and they closely track their resource. Patch size was manipulated by adding various amounts of downed dead wood to the plots (~800 m³ in total); dead trees in the surrounding landscape (~240 km2 ) were identified using airborne laser scanning (light detection and ranging). Over 3 yr, 477 saproxylic species (101,416 individuals) were recorded. Considering 20-1,000 m radii around the patches, local landscapes were identified as having a radius of 40-120 m. Both patch size and habitat amount in the local landscapes independently affected species numbers without a significant interaction effect, hence refuting the island effect. Species accumulation curves relative to cumulative patch size were not consistent with either the habitat-patch hypothesis or the habitat-amount hypothesis: several small dead-wood patches held more species than a single large patch with an amount of dead wood equal to the sum of that of the small patches. Our results indicate that conservation of saproxylic beetles in forested regions should primarily focus on increasing the overall amount of dead wood without considering its spatial arrangement. This means dead wood should be added wherever possible including in local landscapes with low or high dead-wood amounts. For species that have disappeared from most forests owing to anthropogenic habitat degradation, this should, however, be complemented by specific conservation measures pursued within their extant distributional ranges.
Asunto(s)
Escarabajos/fisiología , Bosques , Animales , Ecosistema , Árboles , MaderaRESUMEN
The forage maturation hypothesis (FMH) states that herbivores should follow the onset of growth in spring to obtain access to forage of higher quality and quantity, the so-called "green wave surfing." Several studies have found correlative evidence in support of this by associating animal movement with plant phenology. However, experimental manipulation of vast natural systems determining causes of large herbivore movement is usually beyond reach. The unique management system involving winter enclosures for wild red deer (Cervus elaphus) in Germany facilitated an opportunity for an experimental approach. We manipulated release dates of red deer into free-ranging conditions in spring, predicting increased overall access to high quality forage if released early (1 April), and more rapid initial movement speed towards higher elevation if released late (15 May). The latter had lower access to high quality forage than individuals released early, as they missed parts of the green wave. In strong support of the FMH, individuals released late moved at faster initial speed than early released individuals which tracked the green wave more closely, both settling when reaching similar elevations. This shows that red deer were flexible in their movements, and they can adapt to new patterns of phenology by phenotypic plasticity.