44 research outputs found

    Distribución y Aspectos Poblacionales del Lobo Ibérico en la Provincia de Ourense / Distribution and Population Aspects of the Iberian Wolf in the Province of Ourense, Spain

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    Para determinar el área de distribución del lobo en la provincia de Ourense (noroeste de España) se realizaron prospecciones de campo consistentes en itinerarios de muestreo para localizar indicios y se enviaron cuestionarios a los Agentes del Servicio de Conservación de la Naturaleza de la Xunta de Galicia y a las Sociedades de Cazadores del área de estudio. Los resultados se registraron sobre cuadrículas U.T.M. 10x10 Km. Se constata presencia del lobo en el 79,2% de las cuadrículas estudiadas, estimando el área de distribución en la provincia en 6.400 km2. Para la localización de los grupos familiares inicialmente se prospectó el territorio a nivel de cuadrículas U.T.M. 10x10 Km y en función de los resultados y la información recibida se eligieron determinadas zonas para realizar estaciones de escucha y espera. Determinamos durante el periodo de estudio la existencia de 25 grupos familiares. La densidad estimada en la provincia es de 2,10 – 3,28 lobos /100 km2. De los casos de mortalidad conocidos entre enero de 1999 y abril de 2002 (n=37), un elevado porcentaje se debió a atropellos (70,27%) principalmente en dos vías concretas y un 8,10% correspondió a envenenamientos. Actualmente la densidad del lobo en Ourense es superior a la obtenida en provincias limítrofes, pero amenazas de origen antrópico tanto directas (veneno, persecución ilegal...) como indirectas (incendios forestales, grandes infraestructuras viales, parques eólicos...) pueden estar condicionando la existencia de grupos familiares e incluso la presencia de la especie en determinadas zonas

    Distribución y Aspectos Poblacionales del Lobo Ibérico (Canis lupus signatus) en las Provincias de Pontevedra y A Coruña (Galicia)/Distribution and Population Aspects of the Iberian Wolf (Canis lupus signatus) in the Provinces of Pontevedra and A Coruña (Galicia, Spain)

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    Wolf distribution range in Pontevedra and A Coruña provinces (north-west of the Iberian Peninsula) was determined by field surveys involving sampling routes to locate wolf signs and by questionnaires sent to agents of the Regional Government of Galicia’s Nature Conservation Service and to game societies in the study area. Results were recorded using 10x10 UTM squares. Wolf presence was detected in 67.05% of the squares in the study area, wolf distribution range in both provinces being estimated at approximately 9,600 km2 (6,400 km2 in A Coruña province and 3,200 km2 in Pontevedra province). Wolf distribution is continuous between both provinces, covering mainly the Dorsal Gallega mountain system and the west of A Coruña province. The latter is connected with the rest of the wolf distribution range in Galicia via the north of Pontevedra province. The entire study area was surveyed using 10x10 squares. The areas where most signs were recorded were selected for howling stations and observation points in order to locate packs (cubs and adults). We detected 29 packs (14 and 15 in A Coruña and Pontevedra provinces, respectively), with breeding being confirmed in 52% of them. Population size was estimated at 87-129 wolves in A Coruña province (1.36-2.02 wolves/100 Km2) and 95-140 wolves in Pontevedra province (2.97-4.38 wolves/100 km2). Areas with high wolf density (core populations) were chiefly along the Dorsal Gallega mountain system. Some packs were in highly humanized areas, which may explain why the main cause of the deaths recorded between January 2000 and October 2003 (n=29) was road collision (n=21)

    Movement and heart rate in the Scandinavian brown bear (<i>Ursus arctos</i>)

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    Background: Understanding animal movement facilitates better management and conservation. The link between movement and physiology holds clues to the basic drivers of animal behaviours. In bears, heart rate increases with the metabolic rate during the active phase. Their movement and heart rate change at seasonal and daily scales, and can also depend on environmental factors. Their behaviour is, therefore, flexible in activity patterns with high individual variations. The aim of this study was to establish the relationship between heart rate and distance travelled, and test whether this relationship was influenced by environmental (e.g., time of year and time of day) and biological (e.g., reproductive status, sex, body mass and age of the bears) factors. We analysed data of distance travelled and heart rate of 15 GPS-collared brown bears, both males and females, equipped with cardiac loggers in the south of Sweden in 2014–2017. Results: Heart rate increased with distances travelled exceeding 50 m in an hour, but this correlation depended on the day-of-year with higher heart rate in August than in May. Bears accompanied by cubs had lower heart rate than solitary bears especially in May. When movement was minimum (< 50 m in an hour), heart rate was not related to distance travelled and was very variable, regardless of the months. Conclusions: Our findings suggest that heart rate increases with long distances travelled, but varies with day-of-year and reproductive status, depending on the metabolic rate. Studying the change in heart rate in bears can help to evaluate their seasonal rhythms and how different factors affect them. This study illustrates the usefulness of combined bio-logging proxies, i.e., movement and heart rates in our case, in animal ecology. Distance travelled, GPS positions, Cardiac bio-logger, Seasonal variation, Reproductive statuspublishedVersio

    Wolves, people, and brown bears influence the expansion of the recolonizing wolf population in Scandinavia

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    Interspecific competition can influence the distribution and abundance of species and the structure of ecological communities and entire ecosystems. Interactions between apex predators can have cascading effects through the entire natural community, which supports broadening the scope of conservation from single species to a much wider ecosystem perspective. However, competition between wild large carnivores can hardly be measured experimentally. In this study, we analyzed the expansion of the Scandinavian wolf ( Canis lupus ) population during its recovery from the early 1990s. We took into account wolf-, habitat-, human- and brown bear ( Ursus arctos )-related factors, because wolf expansion occurred within an area partially sympatric with bears. Wolf pair establishment was positively related to previous wolf presence and was negatively related to road density, distance to other wolf territories, and bear density. These findings suggest that both human-related habitat modification and interspecific competition have been influential factors modulating the expansion of the wolf population. Interactions between large carnivores have the potential to affect overall biodiversity. Therefore, conservation-oriented management of such species should consider interspecific interactions, rather than focusing only on target populations of single species. Long-term monitoring data across large areas should also help quantify and predict the influence of biotic interactions on species assemblages and distributions elsewhere. This is important because interactive processes can be essential in the regulation, stability, and resilience of ecological communitie

    Behavioral reactions of brown bears to approaching humans in Fennoscandia

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    Human disturbance causes behavioral responses in wildlife, including large carnivores. Previous research in Scandinavia has documented that brown bears (Ursus arctos) show a variety of behavioral reactions to different human activities. We investigated how proximity to human settlements and roads, as proxies of human influence, affected brown bears' reactions to encountering humans. We analyzed experimental approaches to GPS collared bears, 18 males and 23 single females, in Sweden (n = 148 approaches) and Finland (n = 33), conducted between 2004 and 2012. The bears in Finland inhabited areas with higher human density compared to Sweden. However, the proportion of bears staying or moving when approached and the flight initiation distances were similar in both countries. In Sweden, the flight responses were not dependent on human densities or roads inside the bears' home ranges or the distances from the bears to roads and settlements. Brown bears in Fennoscandia live in areas with relatively low human population densities, but in many areas with high forestry road densities. Our results show that bears' flight reactions were consistent between areas, which is an important message for management, reinforcing previous studies that have documented human avoidance by bears at different spatial and temporal scales.Peer reviewe

    Of wolves and bears: Seasonal drivers of interference and exploitation competition between apex predators

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    This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made. © 2022 The Authors. Ecological Monographs published by Wiley Periodicals LLC on behalf of Ecological Society of America.Competition between apex predators can alter the strength of top-down forcing, yet we know little about the behavioral mechanisms that drive competition in multipredator ecosystems. Interactions between predators can be synergistic (facilitative) or antagonistic (inhibitive), both of which are widespread in nature, vary in strength between species and across space and time, and affect predation patterns and predator–prey dynamics. Recent research has suggested that gray wolf (Canis lupus) kill rates decrease where they are sympatric with brown bears (Ursus arctos), however, the mechanisms behind this pattern remain unknown. We used data from two long-term research projects in Scandinavia (Europe) and Yellowstone National Park (North America) to test the role of interference and exploitation competition from bears on wolf predatory behavior, where altered wolf handling and search time of prey in the presence of bears are indicative of interference and exploitation competition, respectively. Our results suggest the mechanisms driving competition between bears and wolves were dependent on the season and study system. During spring in Scandinavia, interference competition was the primary mechanism driving decreased kill rates for wolves sympatric with bears; handling time increased, but search time did not. In summer, however, when both bear and wolf predation focused on neonate moose, the behavioral mechanism switched to exploitation competition; search time increased, but handling time did not. Alternartively, interference competition did affect wolf predation dynamics in Yellowstone during summer, where wolves prey more evenly on neonate and adult ungulates. Here, bear presence at a carcass increased the amount of time wolves spent at carcasses of all sizes and wolf handling time for small prey, but decreased handling time for the largest prey. Wolves facilitate scavenging opportunities for bears, however, bears alter wolf predatory behavior via multiple pathways and are primarily antagonistic to wolves. Our study helps to clarify the behavioral mechanisms driving competition between apex predators, illustrating how interspecific interactions can manifest into population-level predation patterns.publishedVersio

    Of wolves and bears: Seasonal drivers of interference and exploitation competition between apex predators

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    Competition between apex predators can alter the strength of top-down forcing, yet we know little about the behavioral mechanisms that drive competition in multipredator ecosystems. Interactions between predators can be synergistic (facilitative) or antagonistic (inhibitive), both of which are widespread in nature, vary in strength between species and across space and time, and affect predation patterns and predator–prey dynamics. Recent research has suggested that gray wolf (Canis lupus) kill rates decrease where they are sympatric with brown bears (Ursus arctos), however, the mechanisms behind this pattern remain unknown. We used data from two long-term research projects in Scandinavia (Europe) and Yellowstone National Park (North America) to test the role of interference and exploitation competition from bears on wolf predatory behavior, where altered wolf handling and search time of prey in the presence of bears are indicative of interference and exploitation competition, respectively. Our results suggest the mechanisms driving competition between bears and wolves were dependent on the season and study system. During spring in Scandinavia, interference competition was the primary mechanism driving decreased kill rates for wolves sympatric with bears; handling time increased, but search time did not. In summer, however, when both bear and wolf predation focused on neonate moose, the behavioral mechanism switched to exploitation competition; search time increased, but handling time did not. Alternartively, interference competition did affect wolf predation dynamics in Yellowstone during summer, where wolves prey more evenly on neonate and adult ungulates. Here, bear presence at a carcass increased the amount of time wolves spent at carcasses of all sizes and wolf handling time for small prey, but decreased handling time for the largest prey. Wolves facilitate scavenging opportunities for bears, however, bears alter wolf predatory behavior via multiple pathways and are primarily antagonistic to wolves. Our study helps to clarify the behavioral mechanisms driving competition between apex predators, illustrating how interspecific interactions can manifest into population-level predation patterns.publishedVersio

    A Standardized Method for Experimental Human Approach Trials on Wild Wolves

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    "Copyright © 2022 Eriksen, Versluijs, Fuchs, Zimmermann, Wabakken, Ordiz, Sunde, Wikenros, Sand, Gillich, Michler, Nordli, Carricondo-Sanchez, Gorini and Rieger. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms"As wolves recolonize areas of Europe ranging from moderate to high anthropogenic impact, fear of wolves is a recurring source of conflict. Shared tools for evaluating wolf responses to humans, and comparing such responses across their range, can be valuable. Experiments in which humans approach wild wolves can increase our understanding of how wolves respond to humans, facilitating human-wolf coexistence. We have developed the first standardized protocol for evaluating wolf responses to approaching humans using high-resolution GPS data, and tested it on wild wolves. We present a field protocol for experimentally approaching GPS-collared wolves, a descriptive comparison of two statistical methods for detecting a measurable flight response, a tutorial for identifying wolf flight initiation and resettling positions, and an evaluation of the method when reducing GPS positioning frequency. The field protocol, a data collection form, and the tutorial with R code for extracting flight parameters are provided. This protocol will facilitate studies of wolf responses to approaching humans, applicable at a local, national, and international level. Data compiled in a standardized way from multiple study areas can be used to quantify the variation in wolf responses to humans within and between populations, and in relation to predictors such as social status, landscape factors, or human population density, and to establish a baseline distribution of wolf response patterns given a number of known predictors. The variation in wolf responses can be used to assess the degree to which results can be generalized to areas where GPS studies are not feasible, e.g., for predicting the range of likely wolf behaviors, assessing the likelihood of wolf-human encounters, and complementing existing tools for evaluating reports of bold wolves. Showing how wolves respond to human encounters should help demystify the behavior of wild wolves toward humans in their shared habitat.publishedVersio
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