1,720,972 research outputs found
Temporal overlap among small- and medium-sized mammals in a grassland and a forest–alpine meadow of Central Asia
No full textAssessing carnivores and prey temporal activity patterns as well as their overlap provides valuable insights into behavioural mitigations of competition. Moon phases may also play an important role in shaping wild mammals’ activity rhythms with prey showing peaks of activity in darkest nights. Camera trapping has enriched the possibility to conduct systematic studies of activity patterns and temporal niche overlap on mammalian guilds. In this study, we used camera traps to investigate intra-guild interactions and temporal partitioning among three meso-carnivores and their common prey in two Mongolian areas characterized, respectively, by a grassland and a forest–alpine meadow. We detected a moderate–high interspecific overlap in red foxes, pikas and tolai hares. We found a moderate overlap of temporal activity patterns among nocturnal carnivores as well as among nocturnal prey species. Interestingly, we observed a moderate overlap between hares and meso-carnivores. Amongst nocturnal species, the red fox and the stoat had a peak in activity in the brightest nights, the stone marten and the Mongolian silver vole preferred to range in dark nights, whereas activity of the tolai hare was not dependent on moon phases. Our work provides some first insights of temporal pattern interactions within a small- and meso-mammal assemblage in Central Asia. Our results indicate that meso-carnivores and their potential prey can co-occur in Central Mongolia by means of temporal partitionin
A Spotlight on Mustelids of the Southern Mongolian Forest
No full textLittle is known about the mustelids status and distribution in Mongolia: twelve native species occur in
the country (Batsaikhan et al. 2014). Only Martes zibelllina is locally threatened, while the data related
to the most of the species are deemed deficient (Clark et al. 2006). Between August and October 2018,
a camera trapping survey was conducted in the Khangai Nuuru National Park, which hosts the southernmost forest, in Mongolia. The study area includes forest patches, grassland and alpine vegetation above the tree line.We sampled approximately 60km2, displaying 40 camera traps in front of mid-large carnivores marking points and animal trails, keeping a minimum distance between cameras of 800m. The results demonstrated the area provide a rich carnivore guild with a surprisingly high density of mustelids species, other than canids and felids (five other species). In fact, on a minimum explored area of 15km2, seven species were detected, the 58.3% of those occurring in the country. The species list include: Gulo
gulo, Martes foina, Mustela eversmanii, Meles leucurus, Mustela sibirica, Mustela erminea and Mustela nivalis. Furs from all of them have been found in the herders houses, as well as in markets and shopping
malls of Ulaanbaatar, underlying the strong hunting pressure still present. The study area can be considered a mustelids hotspot due to the high density in a such limited area (which should host also Mustela altaica). The high variety of mustelid species could let infer an intraguild low competition, probably related to the differences in body size, food specialization and
largely differentiated prey availability (eg Aunapuu & Oksanen 2003). We strongly encourage a study aimed to assess the status and the conservation effectiveness of mustelids in the Central Mongolia, to address local institutions towards the proper protection actions
Discovering mammal diversity by phototrapping in the Khangai Nuruu National Park (Mongolia)
No full textOccupancy and activity rhythms of the Siberian roe deer
Full text linkThe assessment of spatiotemporal behaviour patterns of wild species is pivotal both for conservation and for management, especially when involving rare or elusive species, or species living in delicate ecosystems, e.g. mountains. The Siberian roe deer Capreolus pygargus is a native Asian ungulate, whose ecology is still poorly known, especially on mountain ecosystems. In particular, information on its spatial behaviour and temporal patterns of activity is poor. We have assessed its patterns of circadian rhythms in relation to moon phases, with some conclusions on spatial behaviour in respect to potential predation and slope inclination. Data were collected between August and October 2019, with 35 camera-traps deployed over an area of mountain forests alternated to steppe, in Central Mongolia. Camera trap data were analyzed with occupancy models and kernel smoothers, providing a reliable assessment of the presence of Siberian roe deer, with only 1 % of false absence and a very high detection probability. This ungulate showed a bimodal temporal behaviour, with activity peaks at dawn and at early night, irrespective from moon phases. The detection of Siberian roe deer was negatively influenced by the presence of large carnivores and by increasing slope steepness
Activity overlap between mesocarnivores and prey in the Central Mongolian steppe
No full textResearch on the ecology and behaviour of mesocarnivores and their prey is scant in Mongolia. We investigated activity patterns of a guild of mesocarnivores (red fox, Pallas's cat and beech marten) and their prey (Siberian marmot, Daurian pika, Brandt vole, Mongolian gerbil and Mongolian silver vole) using 21 camera traps (effort = 1155 camera days) in Central Mongolia from 25st of May to 20th August 2019. Activity patterns of mesocarnivores were cathemeral (i.e. no difference between diurnal, nocturnal and crepuscular detections, although activity peaked at sunrise). Among prey, the Siberian marmot and the Daurian pika were diurnal, whereas the Mongolian gerbil and the Mongolian silver vole were not generally crepuscular. Beech marten, the smallest mesocarnivore species, was temporally segregated from the other (and larger) mesocarnivore species. Temporal segregation between mesocarnivores and prey was evident between the following pairs: red fox vs Brandt's vole and Mongolian gerbil; Pallas's cat vs Siberian marmot, Brandt's vole and Mongolian gerbil; and beech marten vs Siberian marmot, Daurian pika and the Mongolian silver vole. Activity overlap between mesocarnivores and prey ranged considerably. Activity overlap between the beech marten and prey was lower than that of the other mesocarnivores. Temporal overlap among mesocarnivores and between mesocarnivores and prey seemed to be related to species-specific traits, while also being mediated by local prey abundance. We suggest future surveys should be stratified based on habitat and on the target species, while also integrating different survey methods (e.g. camera traps and live trapping of small mammals)
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
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