129 research outputs found

    Pets becoming established in the wild: free–living Vietnamese potbellied pigs in Spain

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    Mascotas que se establecen en la naturaleza: cerdos vietnamitas que viven en libertad en España Los cerdos vietnamitas (Sus scrofa) son una mascota habitual en Norteamérica y Europa; sin embargo, su popularidad ha disminuido recientemente y esto ha provocado que se abandonen cada vez más. El objetivo principal de este trabajo es identificar casos de cerdos vietnamitas que viven en libertad en España a través de una búsqueda exhaustiva en Google. Se han identificado 42 casos de cerdos vietnamitas que viven en libertad distribuidos por todo el país. El número de casos aumenta cada año, aunque la abundancia de la especie aún parece ser baja. También se han observado indicios de que los cerdos vietnamitas se reproducen en libertad y de posibles híbridos de éstos con jabalíes o cerdos asilvestrados. El hecho de que los cerdos vietnamitas vivan en libertad podría reducir el patrimonio genético de la población española de jabalí, así como agravar los daños que este ya causa en España (como los daños a cultivos o los accidentes de tráfico). Con vistas a evitar que se establezcan en hábitats naturales, es urgente evaluar y gestionar debidamente las observaciones de cerdos vietnamitas salvajes.Vietnamese potbellied (VPB) pigs (Sus scrofa) are a common pet in North America and Europe, but their recent decrease in popularity has increased their abandonment. Our main aim was to identify potential cases of free–living VPB pigs in Spain through an in–depth Google search. We identified 42 cases of free–living VPB pigs distributed throughout the country. The number of free–living VPB pigs reported increased by year but the species abundance still seems to be low. Signs of VPB pig reproduction and possible hybrids between VPB pigs and wild boar or feral pigs have been also reported. Free–living VPB pigs could erode the gene pool of the Spanish wild boar population and exacerbate the damage (e.g. crop damage or spread of diseases) already caused by wild board. Urgent evaluation and adequate management of wild VPB pig sightings is needed to prevent their establishment in natural habitats.Mascotas que se establecen en la naturaleza: cerdos vietnamitas que viven en libertad en España Los cerdos vietnamitas (Sus scrofa) son una mascota habitual en Norteamérica y Europa; sin embargo, su popularidad ha disminuido recientemente y esto ha provocado que se abandonen cada vez más. El objetivo principal de este trabajo es identificar casos de cerdos vietnamitas que viven en libertad en España a través de una búsqueda exhaustiva en Google. Se han identificado 42 casos de cerdos vietnamitas que viven en libertad distribuidos por todo el país. El número de casos aumenta cada año, aunque la abundancia de la especie aún parece ser baja. También se han observado indicios de que los cerdos vietnamitas se reproducen en libertad y de posibles híbridos de éstos con jabalíes o cerdos asilvestrados. El hecho de que los cerdos vietnamitas vivan en libertad podría reducir el patrimonio genético de la población española de jabalí, así como agravar los daños que este ya causa en España (como los daños a cultivos o los accidentes de tráfico). Con vistas a evitar que se establezcan en hábitats naturales, es urgente evaluar y gestionar debidamente las observaciones de cerdos vietnamitas salvajes

    Provision of artificial warrens as a means to enhance native wild rabbit populations: what type of warren and where should they be sited?

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    In Spain, wild rabbits are essential for some highly endangered species, and, therefore, many actions have been undertaken to increase their populations. In the present study, artificial warrens are provided as a means to increase shelter for native wild rabbit populations in a given area. We evaluate the use of three types of warrens by rabbits and the effect on that use of five habitat characteristics at two spatial scales (500 × 500-m grids and 25-m plots). To evaluate that use, we identified pre-established signs at the entrances to each warren, and based on this, we calculated occupancy rate and activity. Our results indicate that rabbit abundance within a grid is the only variable which simultaneously explains both the greater occupancy and the higher activity in the artificial warrens located in that grid. Some 73.2% of the grids showed signs of rabbit use at the time of the evaluation. However, the pre-existing rabbit populations within the grids were not quantified and, hence, we cannot state that the warrens contributed to an increase in the rabbit abundance. Regarding the habitat, our results reveal that warrens should be situated in grids with food coverage of less than 50%, while the use of each individual refuge is greater where food availability in the immediate surroundings is at least 20% and shelter at least 50%. The tube warrens showed significantly greater rabbit use than the other types while there was little difference between the stone and pallet warrens in terms of use

    Effectiveness of habitat management in the recovery of low-density populations of wild rabbit.

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    Understanding the relationship between spatial patterns of landscape attributes and population presence and abundance is essential for understanding population processes as well as supporting management and conservation strategies. This study evaluates the influence of three factors: environment, habitat management, and season on the presence and abundance of the wild rabbit (Oryctolagus cuniculus), an important prey species for Mediterranean endangered predator species. To address this issue, we estimated wild rabbit presence and abundance by latrine counting in transects located in 45 plots within a 250×250 m grid from June 2007 until June 2009 in a 1,200 ha hunting area in southern Portugal.We then analyzed how wild rabbit presence and abundance correlatewith the aforementioned factors. Our results showed that the main variable influencing wild rabbit presence and abundance was the distance to the artificial warrens. North and northeast slope directions were negatively related to wild rabbit presence. Conversely, rabbit presence was positively correlated with short distances to ecotone, artificial warrens, and spring. Regarding rabbit abundance, in addition to artificial warrens, soft soils, bushes, and season also had a positive effect. We found that environmental variables, management practices, and season each affect wild rabbit presence and abundance differently at a home range scale in low-density population. Thus, our major recommendations are reducing the distance to artificial warrens and ecotone, ideally to less than 100 m, and promoting habitat quality improvement on slopes with plenty of sun exposure

    Rewilding and the risk of creating new, unwanted ecological interactions

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    Through a global and interdisciplinary lens, this book discusses, analyzes and summarizes the novel conservation approach of rewilding. The volume introduces key rewilding definitions and initiatives, highlighting their similarities and differences. It reviews matches and mismatches between the current state of ecological knowledge and the stated aims of rewilding projects, and discusses the role of human action in rewilding initiatives. Collating current scholarship, the book also considers the merits and dangers of rewilding approaches, as well as the economic and socio-political realities of using rewilding as a conservation tool. Its interdisciplinary nature will appeal to a broad range of readers, from primary ecologists and conservation biologists to land managers, policy makers and conservation practitioners in NGOs and government departments. Written for a scientifically literate readership of academics, researchers, students, and managers, the book also acts as a key resource for advanced undergraduate and graduate courses

    Daños: Evaluación de un problema

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    Mientras hay zonas en las que el conejo prácticamente ha desaparecido debido a enfermedades como la RHD, en otras sus desproporcionadas poblaciones causan grandes daños en los cultivos. En el artículo que publicamos a continuación, un equipo de investigadores analiza estadísticamente este fenómeno mediante las quejas de los agricultores aparecidas en internet comparadas con otros datos, una forma original y operativa de entender el problema a escala nacional

    A large-scale assessment of European rabbit damage to agriculture in Spain

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    BACKGROUND: Numerous small and medium-sized mammal pests cause widespread and economically significant damage to crops all over the globe. However, most research on pest species has focused on accounts of the level of damage. There are fewer studies concentrating on the description of crop damage caused by pests at large geographical scales, or on analysing the ecological and anthropogenic factors correlated with these observed patterns. We investigated the relationship between agricultural damage by the European rabbit (Oryctolagus cuniculus) and environmental and anthropogenic variables throughout Spain. RESULTS: Rabbit damage was mainly concentrated within the central-southern regions of Spain. We found that rabbit damage has increased significantly between the early 2000s and 2013. Greater losses were typical of those areas where farming dominated and natural vegetation was scarce, where main railways and highways were present, and where environmental conditions were generally favourable for rabbit populations to proliferate. CONCLUSIONS: From our analysis we suggest that roads and railway lines act as potential corridors along which rabbits can spread. The recent increase in Spain of such infrastructure may explain the rise in rabbit damage reported in this study. Our approach is valuable as a method for assessing drivers of wildlife pest damage at large spatial scales, and can be used to propose methods to reduce human-wildlife conflict

    Molecular characterisation of virulence graded field isolates of myxoma virus

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    <p>Abstract</p> <p>Background</p> <p><it>Myxoma virus </it>(MV) has been endemic in Europe since shortly after its deliberate release in France in 1952. While the emergence of more resistant hosts and more transmissible and attenuated virus is well documented, there have been relatively few studies focused on the sequence changes incurred by the virus as it has adapted to its new host. In order to identify regions of variability within the MV genome to be used for phylogenetic studies and to try to investigate causes of MV strain attenuation we have molecularly characterised nine strains of MV isolated in Spain between the years 1992 and 1995 from wide ranging geographic locations and which had been previously graded for virulence by experimental infection of rabbits.</p> <p>Results</p> <p>The findings reported here show the analysis of 16 genomic regions accounting for approximately 10% of the viral genomes. Of the 20 genes analysed 5 (M034L, M069L, M071L, M130R and M135R) were identical in all strains and 1 (M122R) contained only a single point mutation in an individual strain. Four genes (M002L/R, M009L, M036L and M017L) showed insertions or deletions that led to disruption of the ORFs.</p> <p>Conclusions</p> <p>The findings presented here provide valuable tools for strain differentiation and phylogenetic studies of MV isolates and some clues as to the reasons for virus attenuation in the field.</p

    Laying the Foundations for a Human-Predator Conflict Solution: Assessing the Impact of Bonelli's Eagle on Rabbits and Partridges

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    BACKGROUND: Predation may potentially lead to negative effects on both prey (directly via predators) and predators (indirectly via human persecution). Predation pressure studies are, therefore, of major interest in the fields of theoretical knowledge and conservation of prey or predator species, with wide ramifications and profound implications in human-wildlife conflicts. However, detailed works on this issue in highly valuable--in conservation terms--Mediterranean ecosystems are virtually absent. This paper explores the predator-hunting conflict by examining a paradigmatic, Mediterranean-wide (endangered) predator-two prey (small game) system. METHODOLOGY/PRINCIPAL FINDINGS: We estimated the predation impact ('kill rate' and 'predation rate', i.e., number of prey and proportion of the prey population eaten, respectively) of Bonelli's eagle Aquila fasciata on rabbit Oryctolagus cuniculus and red-legged partridge Alectoris rufa populations in two seasons (the eagle's breeding and non-breeding periods, 100 days each) in SE Spain. The mean estimated kill rate by the seven eagle reproductive units in the study area was c. 304 rabbits and c. 262 partridges in the breeding season, and c. 237 rabbits and c. 121 partridges in the non-breeding period. This resulted in very low predation rates (range: 0.3-2.5%) for both prey and seasons. CONCLUSIONS/SIGNIFICANCE: The potential role of Bonelli's eagles as a limiting factor for rabbits and partridges at the population scale was very poor. The conflict between game profitability and conservation interest of either prey or predators is apparently very localised, and eagles, quarry species and game interests seem compatible in most of the study area. Currently, both the persecution and negative perception of Bonelli's eagle (the 'partridge-eating eagle' in Spanish) have a null theoretical basis in most of this area
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