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

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?

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.

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

Adaptive anti-predatory responses of European rabbits exposed to different predation pressure

Prey species develop anti-predatory strategies as a response to minimising the risk of being predated. However, how the European rabbit (Oryctolagus cuniculus) adapts to different predator pressure is not fully known. Here, we studied the adaptive anti-predatory responses of European rabbits exposed to different terrestrial predation pressure. To do this, we took advantage of a rabbit translocation programme in the Sierra Norte Natural Park of Sevilla (SW Spain), where rabbits from the same donor population were translocated in plots with and without terrestrial predator exclusion fences (aerial predation was not excluded in any of the plots). This presented an ideal opportunity to observe whether the behaviour of individuals from the same population adapts to situations with different predator pressure; thus, their behaviour was evaluated through direct observations. Although most rabbits were observed close to cover, differences in distance to cover, group size and behaviour were observed between fenced and unfenced plots. Overall, both adult and juvenile rabbits moved further from cover in the unfenced plot than in the fenced plot. Most of the observations in the unfenced plot corresponded to rabbits in pairs or alone; whereas in the fenced plot, rabbits were primarily in pairs or in larger groups. Our findings suggest that in the unfenced plot, rabbits that moved further from cover were often part of larger groups (≥ 4 rabbits); whereas in the fenced plot, it was rabbits in smaller groups (< 4 rabbits). Rabbits in the unfenced plot were alert and running more frequently than rabbits in the fenced one; in the latter, these rabbits were mostly feeding. Other relaxed behaviours such us grooming or resting were more frequent close to cover. In summary, our results highlight rabbits' capacity to promptly adjust behaviour in response to predation risk, exhibiting adaptive anti-predatory responses tailored to different predation pressures. These insights contribute to understanding the nuanced dynamics of prey species' responses to diverse predation scenarios

Rewilding and the risk of creating new, unwanted ecological interactions

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

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

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

Daños: Evaluación de un problema

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

Factors affecting survival in Mediterranean populations of the Eurasian eagle owl

The survival rate is a key parameter for population management and the monitoring of populations. Thus, an analysis of survival rate variations and the factors influencing the same is essential for understanding population dynamics. Here, we study the factors determining the survival and the causes of mortality of the Eurasian eagle owl (Bubo bubo) in two Spanish Mediterranean populations (Murcia and Seville) where the species has a high population density and breeding success; yet its survival rates and the factors that affect them are unknown. Between 2003 and 2010, 63 breeding owls were captured and radio-tracked. Three monthly (quarterly) survival rates were estimated using known-fate models in the program MARK. The mean overall annual survival rate was 0.776 (95 % CI: 0.677, 0.875). We observed survival differences between sexes, and between the breeding and non-breeding periods, although no overwhelming support was found for any particular model. We concluded that (i) females have a lower survival rate than males, probably due to their larger home ranges, which increase the risk of mortality; (ii) the survival rates of both sexes were lower during the non-breeding period; and (iii) the causes of mortality differed significantly between the two populations, gunshot being the main cause in Seville and electrocution in Murcia.Peer Reviewe