40 research outputs found

    NESTING ECOLOGY OF THE ENDANGERED CHILEAN WOODSTAR (EULIDIA YARRELLII)

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    Abstract ∙ The Chilean Woodstar (Eulidia yarrellii) is a critically endangered hummingbird of the Atacama desert in northern Chile, with a population estimate of around 320 individuals in 2017. To generate useful information for the design of population-recovery actions, we conducted a study of the nesting ecology of the species between 2006 and 2008. Our specific goals were to provide a quantitative description of the species breeding habitat, to describe the basic breeding biology of the species, and to assess the current levels of nesting success. Most of our work was conducted in the valleys of Azapa and Vitor, two of the three last valleys where the species is known to persist. Although we recorded some juveniles in Azapa, we only observed the species nesting in one site in Chaca (Vitor valley), in a small (1.4 ha) olive grove where 13–20 simultaneous nests were found during the studied breeding seasons. Nesting occurs in September–October, and its timing is apparently synchronized with the flowering of chañar (Geoffroea decorticans). The species has a particularly long breeding period with an average of 48 days (17 d for the egg stage, 31 d for the nestling stage). The Mayfield index of nest success ranged from 21–44%. The probability of nest failure was significantly higher closer to the feeding areas. The implications of our results for a habitat restoration program are discussed, particularly the different requirements of females and males. Resumen ∙ Ecología reproductiva del Picaflor de Arica (Eulidia yarrellii), una especie amenazada El Picaflor de Arica (Eulidia yarrellii) es un colibrí críticamente amenazado del desierto de Atacama en el norte de Chile, con una población estimada en el año 2017 de alrededor 320 individuos. Para generar información útil para el diseño de acciones de recuperación de la especie, entre 2006 y 2008 realizamos un estudio sobre la ecología de nidificación de la especie. Los objetivos específicos fueron proporcionar una descripción cuantitativa del hábitat de nidificación, describir la biología reproductiva y evaluar el éxito de nidada de la especie. La mayor parte de nuestro trabajo se realizó en los valles de Azapa y Vitor, dos de los tres últimos valles donde aún persiste la especie. Aunque hemos registrado algunos juveniles en Azapa, sólo observamos nidificación de la especie en un sitio en Chaca (valle Vitor), en un pequeño olivar (1,4 ha) donde se encontraron 13–20 nidos simultáneos para las temporadas de nidificaciones estudiadas. El período reproductivo ocurre en septiembre-octubre, está aparentemente sincronizado con el florecimiento del chañar (Geoffroea decorticans). La especie tiene un período de cría particularmente largo con un promedio de 48 días (17 días de incubación, 31 días los polluelos permanecen en el nido). El índice de Mayfield de éxito de las nidadas varió entre 21 y 44%. La probabilidad de fracaso del nido fue significativamente mayor más cerca de las áreas de alimentación. Se discuten las implicaciones de nuestros resultados para un programa de restauración de hábitat para la especie, particularmente las diferencias entre los requerimientos de los machos y las hembras

    Persistence of Dromiciops gliroides in landscapes dominated by Pinus radiata plantations

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    © The Author(s). 2017. Background: Monitos del monte (Dromiciops gliroides) are old-growth forest specialists and, thus, believed to be very sensitive to habitat transformation, although some recent studies show some level of plasticity of their habitat selection patterns. Findings: In this note we report on records of D. gliroides living in a very modified environment, composed mostly by industrial pine plantations and small fragments of Nothofagus spp. forests and we report the extension of the northernmost limit of its currently known distribution. Conclusions: Although highly reliant on native vegetation, Dromiciops gliroides has been able to persist in industrial forest landscapes dominated by pine plantations

    Conservation of birds in fragmented landscapes requires protected areas

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    For successful conservation of biodiversity, it is vital to know whether protected areas in increasingly fragmented landscapes effectively safeguard species. However, how large habitat fragments must be, and what level of protection is required to sustain species, remains poorly known. We compiled a global dataset on almost 2000 bird species in 741 forest fragments varying in size and protection status, and show that protection is associated with higher bird occurrence, especially for threatened species. Protection becomes increasingly effective with increasing size of forest fragments. For forest fragments >50 ha our results show that strict protection (International Union for Conservation of Nature [IUCN] categories I–IV) is strongly associated with higher bird occurrence, whereas fragments had to be at least 175 ha for moderate protection (IUCN categories V and VI) to have a positive effect. This meta-analysis quantifies the importance of fragment size, protection status, and their interaction for the conservation of bird species communities, and stresses that protection should not be limited to large pristine areas

    Survival Rates of Forest Passerines in South-central Chile

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    Habitat selection by Torrent Ducks (Merganetta armata armata) in Central Chile: Conservation implications of hydropower production

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    The Torrent Duck (Merganetta armata) inhabits the torrential rivers of the Andean mountains. As part of a long-term study, two rivers important for hydroelectric production were surveyed in Central Chile. Monthly indices of Torrent Duck abundance and reproduction were recorded at 74 sampling points distributed along 35.4 km of river between 2007 and 2009. Habitat variables were measured to determine the factors that influence species abundance. The number of rapids, gradient, total flow, water velocity, relative position to hydropower intakes and abundance of conspecifics were identified as important attributes in Torrent Duck habitat preferences. Torrent Ducks were observed in selected sections of rivers where the presence of rapids, high slopes and high water velocity occurred. These conditions were influenced by the width and shape of the river bed. Spatial segregation among individuals suggests the effect of territoriality. Torrent Ducks tended to avoid the presence of high vehicu
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