1,720,974 research outputs found
Distribution of nocturnal birds (Strigiformes and Caprimulgidae)in relation to land-use types, extent and configuration in agricultural landscapes of Central Italy
No full textGoing out to mate: excursion behaviour of female roe deer
No full textAmong mammals, female searching behaviour for a mate has been poorly investigated in behavioural studies on sexual selection. The social organization of roe deer and its physiological constraints suggest the existence of searching strategies by females. Using radiotracking and direct observation we studied the spatial behaviour and intersexual interactions of 32 roe does during the rut in two areas of Tuscany, central Italy. Respectively, 55% and 33% of females performed excursions outside their usual home ranges during the peak of the rut (15 Jul.-15 Aug.). Excursions ranged from 0.6 to 3.0 km, if measured in a straight line, and lasted 30-52 h. During excursions, females (1) moved quickly in one direction; (2) met and were courted by a male; (3) copulated with a male and (4) returned to their home ranges after mating. Before starting an excursion, roaming females were observed to approach unsuccessfully males already courting other females. Most likely excursions represent a condition dependent mating tactic adopted by a variable proportion of females and involving active searching behaviour. © 2008 The Authors
Activity patterns of the Pine marten (Martes martes) in a Mediterranean woodland: evaluation of preliminary data.
No full textTwo pine martens Martes martes, a male and a female, were radio-tracked (six and eleven months respectively) in a forest area near Siena, Central Italy. Martens were captured using box traps baited with eggs and mice, marked by Passive Integrated Transponders (PITs) and fitted with a VHF radio-collar (Televilt, 60 g.). Individuals were monitored daily and fixes were collected to provide data for a 24 hour period within each week.
During the radio-tracking sessions environmental parameters (temperature, humidity, pressure, precipitation and moon phase) were also collected. The activity pattern was correlated with the environmental factors by Logistic Regression procedure. Nocturnal, diurnal and crepuscular activities were measured as the proportion of active fixes for each phases. Activity differed between seasons and was mainly influenced by the environmental temperature. Martens usually perform nocturnal activity. However, our data showed also a not negligible activity carried out during the day. Diurnal and nocturnal patterns of activity were compared
First report on the distribution of the American mink Neovison vison (Mammalia: Mustelidae) in central Italy
No full textDati preliminari sull’uso dello spazio e sui ritmi di attività dei mustelidi in Italia Centrale.
No full textIn Italia le informazioni sulla biologia dei mustelidi sono ancora scarse e frammentate.
Nella presente ricerca, avviata nel 2005, ci si propone di ampliare le conoscenze sulla
presenza, densità, genetica e ecologia di base (dieta e uso dello spazio) dei mustelidi in alcuni ambienti della Toscana Centrale.
Sono presentati i dati, raccolti a partire dall’agosto 2005, relativi all’uso dello spazio e ai ritmi di attività di 2 martore (Martes martes L.) e 2 tassi (Meles meles L.). L’area di studio, nel Comune di Radicondoli in Provincia di Siena, è caratterizzata da ampie foreste termofile
di cerro, alternate a campi aperti destinati a seminativo, con una rete di fossi, fiumi e laghi artificiali. Gli animali sono stati catturati in trappole costruite secondo il modello di Havahart, marcati con “Passive Integrated Transponder” (PIT) sottocutanei per il riconoscimento individuale e muniti di radiocollare. Sono stati inoltre effettuati prelievi di campioni biologici da destinare alle analisi genetiche. Il monitoraggio radiotelemetrico è stato eseguito su base giornaliera, in modo da ricoprire l’arco delle 24h in una settimana. Gli animali sono stati localizzati utilizzando la tecnica della triangolazione. Durante le sessioni di radiotelemetria sono stati registrati i principali parametri ambientali, mentre per l’analisi dell’uso dello spazio sono state utilizzate carte topografiche 1:25000 e ortofoto della CGR
scala 1:50000. Gli “home range” sono stati calcolati a livello stagionale con il metodo del kernel al 95, 75, 50%. I ritmi di attività sono stati analizzati dividendo le 24h in fasce orarie di 4h ciascuna.
Sino ad ora sono state raccolte circa 300 localizzazioni per la martora e 700 per il tasso. Il tasso è risultato occupare un “home range” estivo più ampio di circa tre volte rispetto a quello invernale, con attività prevalentemente notturna (95% delle localizzazioni) e brevi periodi di semiletargia nei mesi più freddi. La martora ha occupato un “home range” estivo più ampio di circa il doppio rispetto a quello invernale, mostrando un’attività notturna pari al 63% delle localizzazioni. Questi risultati preliminari confermano quanto già riportato in letteratura e costituiscono il primo passo di una ricerca a lungo termine sui mustelidi della Toscana centrale
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
Cost-effectiveness of lures in attracting mammals: results of a large-scale camera-trapping field experiment
No full textWhile there is widespread agreement that camera trapping is revolutionising the way we study wildlife, the use of attractants is still controversial. In particular, to the best of our knowledge, the cost-effectiveness of different attractants used in camera trap surveys has never been assessed. To contribute in filling this knowledge gap we 1) compare the effectiveness of a suite of attractants in detecting widely distributed mammals in Europe and 2) evaluate the cost-effectiveness of these attractants, by calculating the costs associated to reach a specific management objective.
We conducted the field experiment in the spring of 2023 in four study areas in central and northern Italy, encompassing a variety of environments, from lowland forest to alpine beech forest. We deployed camera traps at 60 sites, each consisting of three treatment lure stations (camera trap + treatment) with one control camera station with no lure, placed in a square configuration (side 100 m). The treatments included sardines, a commercial lure for canids and Martes spp. and peanut butter. Cameras were left active at each site for 14-21 days and detection histories of each species were generated using 24h time bins. To model detection probability, we fitted single season multi-method occupancy models for each species, comparing (i) the null model with detection probability constant across treatments and control station, (ii) the ‘method’ model, detectability specific to treatment, and (iii) models with covariates that could affect detection probability (i.e. ‘time since deployment’ and ‘study area’). We further conducted a power analysis to compare the cost-effectiveness of the different treatments. Specifically, we estimated the number of sites to be surveyed and the costs required to detect a decline of 25% in the occupancy of each species.
Through a total of 1047 trap nights of activation, we detected 15 mammalian species, of which 13 were included in the analysis. The most widespread species was the roe deer (detected in 51 sites, across all study areas) and the least widespread was the golden jackal (detected in 8 sites, only in the Karst and Alps study area, 30 sites in total). The ‘method’ model was the top ranking model in the case of 7 species, including two canids (golden jackal and red fox), three mustelids (badger and Martes spp.), two Artiodactyla (red deer and roe deer) and a Rodent (porcupine). The results of the power analysis show how differences in required sampling effort (and costs) between the different attractants and no attractants can be dramatic. As an example, in the case of the Martes spp. monitoring protocol, using peanut butter will require 82 sites (6744 €) as compared with a camera without attractant requiring 486 sites (or 39244 €).
Through our large scale field experiment we found that for seven species detectability varied with the type of attractant used. Specifically, sardines proved to be the most effective attractant for canids and the porcupine, peanut butter was most effective for mustelids but was avoided by the roe deer, whereas the commercial attractant was the most effective with red deer. Through the power analysis combined with the cost function analysis we were able to show striking differences in the cost-effectiveness of the different methods, which strongly emphasizes the critical importance played by the choice of whether to use an attractant or not and the type of attractant to be used
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
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