1,721,074 research outputs found
Sequential use of holes by birds breeding in a natural boreal forest in Mongolia
No full textCapsule Wood Nuthatch Sitto europoea and Coal Tit Periparus ater had a high tendency to reuse nest-sites, and holes in living trees were more frequently reused than holes in dead trees. Aims Patterns of sequential nest-hole use are important in understanding the inter- and intraspecific relationships of hole-nesting birds. We studied the hole reuse at both guild and species level, and examined the characteristics of reused holes. Methods The fieldwork was carried out in a strictly protected area in Mongolia. Occupied nest-holes were searched for all hole-nesting species in two subsequent years. The characteristics of nest-holes and nest trees were recorded. Results Of 105 holes occupied in 2002, 40 (38%) were reused in the following year. The reuse rate for holes previously used by non-excavators was 48%, and subsequent occupation was almost exclusively by the same species. Reuse rates for previous woodpecker and Willow Tit Poecile montanus holes were 31% and 16%, respectively, and the subsequent users were more frequently a different species. Nuthatches and Coal Tits had the highest propensity to reuse holes. Holes located in living parts of trees were reused more often than those in dead wood. Conclusion The tendency to reuse holes could be influenced by the ability to excavate, the ability to compete for nest-sites, and the quality and abundance of preferred hole type of each bird species. The high reuse rate of certain holes would indicate good qualities and/or more limited availability of such holes. The more stable microclimate and greater protection from predation might account for the frequent reuse of holes in living wood
Sequential use of holes by birds breeding in a natural boreal forest in Mongolia
No full textCapsule Wood Nuthatch Sitto europoea and Coal Tit Periparus ater had a high tendency to reuse nest-sites, and holes in living trees were more frequently reused than holes in dead trees. Aims Patterns of sequential nest-hole use are important in understanding the inter- and intraspecific relationships of hole-nesting birds. We studied the hole reuse at both guild and species level, and examined the characteristics of reused holes. Methods The fieldwork was carried out in a strictly protected area in Mongolia. Occupied nest-holes were searched for all hole-nesting species in two subsequent years. The characteristics of nest-holes and nest trees were recorded. Results Of 105 holes occupied in 2002, 40 (38%) were reused in the following year. The reuse rate for holes previously used by non-excavators was 48%, and subsequent occupation was almost exclusively by the same species. Reuse rates for previous woodpecker and Willow Tit Poecile montanus holes were 31% and 16%, respectively, and the subsequent users were more frequently a different species. Nuthatches and Coal Tits had the highest propensity to reuse holes. Holes located in living parts of trees were reused more often than those in dead wood. Conclusion The tendency to reuse holes could be influenced by the ability to excavate, the ability to compete for nest-sites, and the quality and abundance of preferred hole type of each bird species. The high reuse rate of certain holes would indicate good qualities and/or more limited availability of such holes. The more stable microclimate and greater protection from predation might account for the frequent reuse of holes in living wood
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
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
Distribution pattern of an expanding Osprey (Pandion haliaetus) population in a changing environment
No full textWe studied the nest site selection and distribution pattern at landscape level of the German Osprey population, and demonstrated how to test the predictions of the ideal free distribution theory and its derivatives on such an expanding population. Information about the location and breeding success of each Osprey nest site between 1995 and 2005 was collected through a long-term monitoring programme. Data of land cover types were acquired from the administrations of each federal state and the CORINE Land Cover database. The results showed that Ospreys preferred landscapes with more water bodies and forests. Such sites were also occupied earlier and had higher local population density. However, in the study period of 11 years, there was a gradual shift from forest-dominated landscapes to agricultural land-dominated landscapes. The breeding success increased over time, with no difference in the breeding success between pairs nesting on trees and poles, whereas there was higher breeding success at nest sites surrounded by more agricultural land and less forest. The more efficient foraging in eutrophic lakes in agricultural landscapes was the most likely cause for the higher breeding success. The distribution pattern of the Ospreys did not match the resource allocation, which deviated from the models tested. We suggested that the proximate cues used for nest site selection mismatched site quality due to anthropogenic environmental changes
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
Identifying the Scale Thresholds for Field-Data Extrapolation via Spatial Analysis of Landscape Gradients
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