23 research outputs found
Genetic and demographic recovery of an isolated population of brown bear Ursus arctos L., 1758
The brown bear Ursus arctos L., 1758 population of the Cantabrian Mountains (northwestern Spain) became isolated from other bear populations in Europe about 500 years ago and has declined due to hunting and habitat degradation. At the beginning of the 20th century, the Cantabrian population split into eastern and western subpopulations, and genetic exchange between them ceased. In the early 1990s, total population size was estimated to be < 100 bears. Subsequently, reduction in human-caused mortality has brought about an increase in numbers, mainly in the western subpopulation, likely promoting male-mediated migration and gene flow from the western nucleus to the eastern. To evaluate the possible genetic recovery of the small and genetically depauperate eastern subpopulation, in 2013 and 2014 we genotyped hair and faeces samples (116 from the eastern subpopulation and 36 from the western) for 18 microsatellite markers. Data from the annual count of females with cubs of the year (COY) during the past twenty-six years was used to analyze demographic changes. The number of females with COY fell to a minimum of seven in the western and three in eastern subpopulations in the biennium 1993¿1994 and reached a respective maximum of 54 and 10 individuals in 2013¿2014. We also observed increased bear dispersal and gene flow, mainly from the western to the eastern subpopulation. Of the 26 unique genotypes detected in the eastern subpopulation, 14 (54%) presented an admixture composition, and seven (27%) were determined to be migrants from the western subpopulation. Hence, the two separated and clearly structured subpopulations identified in the past currently show some degree of genetic admixture. This research shows the partial demographic recovery and a change in genetic composition due to migration process in a population of bears that has been isolated for several centuriesPeer Reviewe
Challenges for recovery of large carnivores in humanized countries: attitudes and knowledge of sheep farmers towards brown bear in Western Pyrenees, Spain
During 2017, we studied knowledge, perceptions, and attitudes towards brown bears by extensive mountain sheep farmers in the Western Pyrenees, using a structured questionnaire, specifically, whether the scarce bear presence, or the administrative region, was influential. Livestock raising practices are mainly family properties and have suffered a strong decline in the last decades. Despite its low abundance (only 2 bear individuals during the study period in the area), there was a generalized negative attitude towards the presence of bears. Farmers considered bear presence as incompatible with sheep mountain herding. One third of them have experienced bear damages, although this was not the main difficulty for the viability of farming practices. They were able to change husbandry practices after wildlife and dog’s damages, increasing vigilance, hiring shepherds, and using livestock guarding dogs, whose work is perceived as satisfactory. Farmers considered that information available about bear and compensation systems for damages was insufficient, and should be improved
Behaviour of brown bears killing wild ungulates in the Cantabrian Mountains, Southwestern Europe
La Cruz Roja Española, la repatriación de los soldados de las guerras coloniales y el desarrollo de la ciencia médica en España, 1896-1950
El oso en la escuela
Se pretende divulgar el conocimiento de la vida y costumbres del oso y los problemas que le amenazan para frenar, sensibilizando, el proceso de extinción. Por ello los autores dividen su trabajo en 6 partes: ¿qué es un oso?, la alimentación en cada época del año, la hibernación, el uso del espacio y la actividad, el pasado y presente del oso en la Cordillera Cantábrica, el oso y el hombre. Para terminar se incluyen dos propuestas de trabajo para facilitar la realización de tareas desde la escuela. La primera, elaborado por Fernando F. Rojero, está dirigida a EGB, se centra en aspectos biológicos y culturales diseñando actividades motivadoras que el profesor seleccionará adecuándolas al nivel y conocimiento de sus alumno. En la segunda parte, realizada por Raquel Posada, se propone un cuestionario sobre biología y ecología que pretende ayudar a profesores de medias a introducir conceptos generales de zoología y ecología partiendo del ejemplo del oso pardo. Al final se propone un itinerario por el occidente asturiano, así como otra posible activiadad sobre daños y conservación del oso.AsturiasES
Sexually selected infanticide or predation? Killing and consumption of a female brown bear in a male infanticide attempt
Sexually selected infanticides (SSI) committed by male bears during the mating season has attracted a great research attention, although this type of behavior has been rarely observed in the wild. Here, we document a bear infanticide attempt in the Cantabrian Mountains in which the male killed the adult female during the fight and, subsequently, consumed the carcass for several days. Interestingly, in this case, the bear male tried to reach the cub with the apparent intention of killing it, even though the female was already dead. We complement this observation with data on documented cases of SSI events between 1996 and 2020 in the Cantabrian Mountains. We hypothesize that when females are unintentionally killed while defending their cubs in SSI events, males can benefit by feeding on the carcasses.J.V.L.B. was supported by a Ramon & Cajal research contract (RYC-2015-18932) from the Spanish Ministry of Economy, Industry and Competitiveness
Four views on a dildo, and other stories of #fakearchaeology
Resumen del trabajo presentado en la 41st Annual Theoretical Archaeology Group Conference (TAG) >Power, Knowledge and the Past>, celebrada en Longres (Gran Bretaña), del 16 al 18 de diciembre de 2019Short video about the archaeological intervention we carried out in 3 leisure sites in Alicante during May 2019: https://youtu.be/EIO_PGA-G-s#fakearchaeology is about contemporary representations of the past, excavated from abandoned leisure sites. A form of contemporary archaeology that talks about the use of the past in the present. During the last days of May 2019, a group of four archaeologists started to approach some sites in order to develop methodologies for the interventions… and decided to record it.
This ‘paper’ is a screening of four views of fieldwork. Archaeology and daily life in the birth of a new project. An amalgam of clips that try to tell the story of these days, ourselves and the sites. Can these images tell more than a thousand words? We will try to disentangle what we recorded, what we edited and what we actually did
Not exodus, but population increase and gene flow restoration in Cantabrian brown bear (Ursus arctos) subpopulations. Comment on Gregório et al. 2020.
In a genetic study on brown bears (Ursus arctos) in the Cantabrian Mountains, Gregório et al. (2020) interpreted the asymmetrical gene flow they found from the eastern subpopulation towards the western one as an exodus of bears forced to flee from the eastern nucleus "with higher human disturbance and poaching", concluding that connectivity may be operating as a means for eastern Cantabrian bears to find more suitable territories. In this reply, we maintain that the explanations of Gregorio et al. contradict the source-sink theory and we also present demographic data not considered by these authors showing that the eastern subpopulation is not declining, but persistently increasing. After reviewing the demographic and genetic studies published during the last 20 years, we conclude that the connectivity between the two subpopulations is operating as a route which allows the regular movement of males and the restoration of the gene flow across the whole Cantabrian population
Integrating critical periods for bear cub survival into temporal regulations of human activities
Conservation regulations are increasingly recognized as important elements of the available toolkit for effective biodiversity conservation. However, the full integration of evidence when designing these tools is still scarce, which limits the effectiveness of these legal instruments. Increasing concern is emerging on the compatibility between leisure activities and biodiversity conservation, which require a true integration of the best available evidence into policy-making. Managing authorities are required to take actions in order to ensure the compliance of international conservation commitments with species conservation. This is the case of applying spatio-temporal regulations on bear viewing activities in critical bear areas and periods, such as during the cub-rearing period. Here, we took advantage of a unique long-term dataset (>25 years) of observations of females with cubs in the endangered brown bear population in the Cantabrian Mountains, N Spain (>3000 observations from 329 females with cubs) to estimate monthly bear cub survival rates in the first sixteen months of cubs life. Overall, the monthly cub survival in this population was remarkable high, ranging from 0.839 to 0.994 monthly survival rates. The lower monthly cub survival rates were in May and June after the cubs left the den (mean ± SD: 0.839 ± 0.050 and 0.897 ± 0.023, respectively). Infanticide was estimated as the main mortality cause for cubs during the study period. Our results are practical because they can be used to inform conservation policies regarding the most appropriate periods to implement temporal regulations of human activities in bear breeding areas. The most appropriate period to implement such regulations here is the period between the time when the cubs leave the den (late March–April) until and including June; which should be considered in future temporal regulations adopted by Regional Governments in Spain. Accordingly, we also urge an update of the Spanish brown bear strategies considering the new scenario of bear conservation in Spain, including a set of measures related to bear viewing activities.This research has received financial support from the Ministry of Agriculture and Fisheries, Food and Environment of the Government of Spain. JVLB was supported by a Ramon & Cajal research contract (RYC-2015-18932) from the Spanish Ministry of Economy, Industry and Competitiveness.Peer reviewe