86,886 research outputs found
Distance sampling as an effective method for monitoring feral pigeon (Columba livia f. domestica) urban populations
No full textSUMMARY Current methods for estimating feral pigeon (Columba livia f. domestica) population size and for monitoring population trends are mainly based on indices, which according to the current literature on wildlife census methods often produce biased results. Distance Sampling techniques have never been used in this context, even though they could theoretically produce absolute abundance estimates at relatively low costs. The aim of this paper was to investigate the performance of Distance Sampling to census feral pigeons, and to compare these results with those obtained by using Quadrate Counts, a widespread method for monitoring these birds. Surveys were performed in Pisa (Italy) in two different periods of the year 2004 (end of January–beginning of February, and November), which correspond to minimum (January–February) and maximum (November) numbers for pigeon populations. We considered 40 line transects each about 250 m long for Distance Sampling, and 40 250×250 m cells for Quadrate Counts. In both cases, sampling units were randomized in a stratified design. In contrast to Quadrate Counts, Distance Sampling detected the predicted increase of abundance from January–February to November with an acceptable precision and no increase of costs per survey. Even though the possible biases (due to the not rigorously random distribution of transects and to the spiked nature of collected distance data) should be further investigated, results suggest that Distance Sampling is a viable and efficient alternative to the traditional methods used to estimate feral pigeons population size and to monitor trends
Il padule di Suese (Livorno) sito di importanza comunitaria: materiali per un piano di gestione
No full textDati sulla consistenza della popolazione di Occhione (Burhinus oedicnemus) nidificante nel Parco del Taro
No full textCoordinamento dei servizi di Prevenzione sul territorio di una U.S.L. Toscana. Valutazioni sull'efficacia di interventi volti a contenere il fenomeno dell'evasione dall'obbligo vaccinale
No full textOrientation of the pied flycatcher Ficedula hypoleuca: cue-conflict experiments during spring migration
No full textHierarchical relationships among different compass systems in long-distance migrants are still a matter for discussion because different studies have led to highly variable and apparently contradictory results. We carried out cue-conflict experiments during spring migration on pied flycatchers Ficedula hypoleuca (Passeriformes, Muscicapidae). Birds were exposed to a conflict between celestial and magnetic information by altering the polarized light pattern or magnetic field. The polarization pattern was shifted (+/- 90A degrees) with filters, whereas the magnetic field was altered (+90A degrees) through Helmholtz coils. Birds were tested in modified Emlen funnels both before and after the cue conflict; during the tests, only the natural magnetic field was available. This protocol was designed to test whether the experimental birds recalibrated their magnetic compass on the directional information derived from the light polarization pattern when the region near the horizon was visible during the conflict. Contrary to this expectation, we did not record any significant shift in magnetic orientation after one or repeated exposures to the cue conflict. Our results support earlier studies, which suggest that the magnetic field is the primary compass cue during the migratory period
Variations on the Author
No full text“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
A temporal analysis of the foraging flights of feral pigeons (Columba livia f. domestica) from three Italian cities
No full text[Newspaper Clipping: Author Claims Evidence of Second JFK Assassin #1]
No full textNewspaper article titled "Author Claims Evidence of Second JFK Assassin." The article states that author Richard J. Whalen concluded "that there is circumstantial evidence to support the theory of a second assassin in the shooting of President John F. Kennedy.
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