1,721,001 research outputs found
Space use, daily activity and foraging behaviour of common dormouse (Muscardinus avellanarius) in a Mediterranean heterogeneous environment of Central Italy
No full textDespite numerous field studies focused on the basic life history of the common dormouse, little is known about its movements and home range use. The knowledge of how dormice utilize their habitat is essential to outline appropriate conservation management of the species. Therefore, we conducted this study to gather first information on the spacing behaviour in a Mediterranean heterogeneous habitat, with a special attention to home range size, trek length and foraging behaviour. The study was carried out in the Natural Reserve of Castel di Guido, near Rome (41°54'N, 12°31'E), characterized by a mosaic of natural and artificial woods. Natural patches were represented by thermophilous mixed oak woodland dominated by Quercus ilex and Q. cerris, with a dense shrub layer. Artificial patches consisted of an assemblage of planted trees belonging to different species, either deciduous (i.e. Q. pubescens, Acer monspessulanum, Pyrus comunis) or evergreen (i.e. Pinus sp., Q. suber). Finally, edges were composed by several shrubs species as Prunus spinosa, Crataegus monogyna, Spartium junceum, Rubus fruticosus and Ulmus minor. In order to study the space use and daily activity, radiotracking was carried out in four sessions: two in winter (November-December 2003 and 2004) and two in spring (March-April 2004 and April-May 2005). Each session lasted three weeks. Common dormice were captured in nest boxes and were radiotagged using transmitters weighed 1.1 g. Only dormice with body weight of 15 g or more were tagged.Dormice resulted to be completely nocturnal: they left the nest after sunset and came back to it before dawn. Daily activity was affected by photoperiod and possibly by vegetation structure. In fact, when dormice had to move through areas with a scarce vegetation cover, they shortened their daily activity and avoided to move during twilight, probably to reduce the predation risk. Home range (HR) size resulted on average very small for both sexes (♀MCP = 0.36 ha; ♂ MCP = 0.32 ha) and in both seasons (spring MCP = 0.33 ha; winter MCP = 0.35 ha). However, individuals showed marked differences in space use, probably affected by the location and proximity of wood patches within the home range. In winter, dormice used the same area during the three weeks, while in spring the weekly HR shifted over the time. This was probably due to a different food distribution in the two seasons: in winter, food resources were mainly available in thermophilous wood (acorns), while in spring they were more scattered and diversified (elm and maple samaras, coniferous pollen, oak catkins). Since dormice exploited ephemeral food resources, patchily distributed in time and space, their activity within the home ranges was highly concentrated in a few small discrete patches. In particular, the core areas used by females were smaller (11.7 %) than those used by males (17 %). The total distance travelled per night was greater in winter (265.56 ± 28.21 m) than in spring (161.61 ± 8.8 m). This could depend on the longer duration of the night in winter but also on the need to reach the thermophilous deciduous patches where acorns were abundant. On the other hand, no difference were observed between the distance travelled by the two sexes (♀ = 200.33 ± 17.31 m; ♂ = 189.78 ± 14.7 m). In general, our results suggested that spacing behaviour did not differ between sexes. This may be explained by the high habitat patchiness and diversity that could in
Reproductive biology of common dormouse (Muscardinus avellanarius) in a coastal evergreen scrub forest of Central Italy
No full textThe common dormouse (Muscardinus avellanarius) is a widespread European glirid species that occupies a variety of deciduous woodlands throughout the continent. His breeding behaviour has been investigated by several authors using nest boxes in various woodlands of northern Europe, while information from mediterranean habitats is very scarce. Previous studies in Italy suggested that, differently from northern populations, the activity pattern of coastal mediterranean populations is characterized by a regular winter activity, an autumnal breeding period, and a probable summer dormancy, related to climatic factors such as mild winters and dry summers. These marked differences in the activity pattern between temperate and mediterranean populations suggested a different reproductive biology. Therefore, the aim of this research was to study some basic reproduction parameters, i.e. the period and length of breeding season, the number of litter per year, the average litter-size and the first age of breeding females.The study was carried out in a thermophilous evergreen scrub forest dominated by the holm oak (Quercus ilex), within the Natural Reserve of Castelporziano, along the Tyrrhenian coast of Latium region (41°44'N, 12°24'E). Fifty nest boxes were set up in the study site. Boxes were placed at 1.5 m above ground level and spaced at a distance of c. 20 m from each other, according to a rectangular grid. These boxes were inspected monthly from May 2002 to December 2004 and the trapped dormice were weighted, sexed, aged and marked.The study population showed a very long breeding period as compared to northern European populations. Litters began at the end of September and were observed continuatively until the end of March (n=32). The birth peak (84.3%) occurred in autumn (October-December). Juveniles appeared in November and became abundant in December. Females had usually two litters per year and a two-months span was observed between two litters. Litter size was 4.72 (± 0.26), similar to that reported in literature. Breeding young females were never recorded, according to the general observation that common dormice become sexually mature after their first dormancy season (in this case after their first aestivation). In comparison with hibernating populations, the coastal mediterranean populations of common dormouse show a higher reproductive potential. The extension of breeding season, that lasted seven months (September-March), was probably due to the favourable climatic conditions and the constant presence of flowering and fruiting plants from Autumn to Spring. Owing to the length of breeding season, females had two litters per year showing that the reproduction rate of this population may be twice respect to northern populations. The higher reproduction activity in the autumn may be related to the availability of energetic autumnal food, such as acorns (telemetry observations, unpublished), which represent an important trophic resource for females, ensuring a successful pregnancy and weaning. Moreover, juveniles are advantaged by the mild winter which allows them to grow and forage before the summer dormancy
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
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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