1,721,267 research outputs found
IUCN criterions meet reality (or how to classify little know species): the case of Balearic Shearwater
No full textOro Daniel. IUCN criterions meet reality (or how to classify little know species): the case of Balearic Shearwater. In: Ecologia mediterranea, tome 29 n°2, 2003. pp. 249-250
Direct and indirect effects of climate and seed dynamics on the breeding performance of a seed predator at the distribution edge
No full textMarginal populations usually have low densities and are considered to be particularly vulnerable to environmental stochasticity. Using data collected in nest boxes, we analyzed the breeding performance of the edible dormouse (Glis glis), an obligate hibernating rodent and a seed predator in deciduous forests, in two populations at the distribution range's edge. Despite being only 20 km apart from each other, Montseny is a large patch of mixed deciduous forests (oaks and beech), whereas Montnegre would be the harshest habitat, that is, a small, isolated patch with only oaks. First, we studied the differences in climate and tree cover change in the two populations. Second, we analyzed the direct and indirect roles of local climate conditions and seed availability on breeding performance over 10 years in each population. Finally, we explored the influence of tree cover change on the occupancy dynamics in the two populations. Our results showed contrasting responses between populations: in Montseny, asynchronous seed production between oaks and beech precluded skip breeding, and breeding performance increased with seed availability. Furthermore, dormice in Montseny may use pollen production to anticipate the amount of beech nut resources and adjust their breeding effort. Boxes showed higher occupancy and colonization and fewer extinctions in Montseny than in Montnegre, where seed availability did not drive breeding performance. Results from Montnegre suggest that skip breeding was an adaptive response to a more pulsed, harsher environment. Here, females produced a similar number of pups than at Montseny. Long-term studies dealing with population responses in marginal habitats can lead to a deeper understanding of the capacities of organisms to adapt to harsh environments. Although local adaptation is frequently documented across various taxa, studies at the distribution edge may shed light on our still limited comprehension of the underlying mechanisms responsible for its occurrence.We are grateful to all the people helping with the fieldwork. William Cole kindly edited the English text. Marcos Fernandez discussed several topics about seed production and dynamics in Mediterranean ecosystems. Jordina Belmonte kindly provided pollen data. Funds for long-term monitoring of edible dormice were provided by Diputació de Barcelona. The Associate Editor and two anonymous reviewers provided helpful comments to improve the MS.Peer reviewe
Living in the edge: demographic responses driven by density-dependence and pulsed resources in a hibernating mammal
No full textPopulations at the edge of a species' distribution often encounter more challenging environmental conditions than those at the core, requiring unique adaptations and strategies. However, the demographic processes driving these populations remain poorly understood. This study aims to understand these processes and the population stability of the hibernating edible dormouse under challenging environmental conditions in two Iberian edge populations: Montseny and Montnegre. Despite their geographic proximity, Montnegre is demographically isolated and faces a harsher environment characterized by a drier climate and forests with lower deciduous tree diversity, whereas Montseny remains connected to other populations. Using long-term capture–recapture data, we analyzed the effects of density-dependence and seed availability on population growth, survival, and recruitment of dormice. Results indicated that both populations experienced large fluctuations in population growth rate, with a slight mean decline. Survival fluctuated less and was higher in Montseny than in Montnegre, likely reflecting the harsher conditions of the latter. We found a negative relationship between population size and both growth rate and survival in both populations especially in Montnegre, suggesting significant density-dependent effects that varied with stochastic annual seed abundance. This was likely influenced by the pulsed annual acorn production in Montnegre. Contrarily, high asynchrony between beechnut and acorn abundance in Montseny dampened the pulsed dynamics of seed availability. Interestingly, demographic contribution to population growth was dominated by survival in Montseny and by recruitment in Montnegre. When comparing survival rates with Central European core populations, we found that survival decreased with increasing climatic aridity, but was unrelated to proximity to the core, underscoring the role of spatial heterogeneity in habitat suitability, independent of range position. Our findings emphasize the complex interplay between ecological processes and evolutionary mechanisms at the edge of a species' range, highlighting the critical role of local adaptations and resource availability in shaping population dynamics.The study has been funded since its beginning by Diputació de Barcelona (grant no. 2023/0005732).Peer reviewe
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
CSIC Cicerón 13.2 Beneficios de la ganadería extensiva tradicional. Daniel Oro de Rivas
No full textDatos técnicos: 4 minutos, color, español. Ficha técnica: Gabinete de Presidencia CSIC y Departamento de Comunicación.Peer reviewe
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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