10 resultados para Birds nests

em Consorci de Serveis Universitaris de Catalunya (CSUC), Spain


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En un mateix niu un ocell pot incubar ous d'altres espècies sense saber-ho. El cargolet de Nova Guinea ensenya un cant als seus perquè el facin servir com a contrasenya en néixer

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Data about breeding populations of birds in the Antarctica are rare and fragmented. Thus, information about the status of the breeding populations of Antarctic birds is crucial given the current scenario of climate change, which is particularly acute in Antarctica. This paper presents new information about the populations of the Antarctic tern Sterna vittata, the kelp gull Larus dominicanus, the southern giant petrel Macronectes giganteus, the Antarctic skua Catharacta antarctica lonnbergi, the chinstrap penguin Pygoscelis antarctica and the gentoo penguin Pygoscelis papua on Byers Peninsula (Livingston Island, South Shetland Islands). We used line transects counts to estimate both densities and numbers of nests of the different species. We estimate that there are 398.96 birds km-2 of southern giant petrels (2793 individuals), 62.4 birds km-2 of Antarctic tern (3746 individuals) and 269.1 birds km-2 of kelp gull (1884 individuals). Furthermore, we found 15 nests of Antarctic skua in 25 km2, from which we can estimate that 6091 birds must breed on Byers Peninsula. We also censused two colonies of gentoo penguins (3000 and 1200 pairs) and 50 pairs of chinstrap. Compared to previous estimates, gentoo penguins seem to have increased whereas chinstrap penguin have decreased. Finally, the populations of Antarctic tern, southern giant petrel and kelp gull have stabilized or slightly increased.

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Report for the scientific sojourn at the Simon Fraser University, Canada, from July to September 2007. General context: landscape change during the last years is having significant impacts on biodiversity in many Mediterranean areas. Land abandonment, urbanisation and specially fire are profoundly transforming large areas in the Western Mediterranean basin and we know little on how these changes influence species distribution and in particular how these species will respond to further change in a context of global change including climate. General objectives: integrate landscape and population dynamics models in a platform allowing capturing species distribution responses to landscape changes and assessing impact on species distribution of different scenarios of further change. Specific objective 1: develop a landscape dynamic model capturing fire and forest succession dynamics in Catalonia and linked to a stochastic landscape occupancy (SLOM) (or spatially explicit population, SEPM) model for the Ortolan bunting, a species strongly linked to fire related habitat in the region. Predictions from the occupancy or spatially explicit population Ortolan bunting model (SEPM) should be evaluated using data from the DINDIS database. This database tracks bird colonisation of recently burnt big areas (&50 ha). Through a number of different SEPM scenarios with different values for a number of parameter, we should be able to assess different hypothesis in factors driving bird colonisation in new burnt patches. These factors to be mainly, landscape context (i.e. difficulty to reach the patch, and potential presence of coloniser sources), dispersal constraints, type of regenerating vegetation after fire, and species characteristics (niche breadth, etc).

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The Asian Diaspora in the Americas in the 16th and 17th has been neglected by scholars for a long time. This fact is baffling, not only for the great interest of this topic in of itself, but also because it could provide new knowledge of colonial Mexico, especially in terms of the interaction among the many groups that populated the colony. This early movement of people and ideas across the largest extension of water in the planet is characteristic of what has been called the ¿archaic globalization,¿ and thus research on these matters could contribute to the history of globalization.In this presentation, I seek to further elaborate on the themes outlined by Edward Slack in The Chinos in New Spain: A Corrective Lens for a Distorted Image, an article published in 2009 in the Journal of World History. Firstly, I would like to bring forth some evidence that indicates that Asian religious practices were present in Mexico in the 1600s. Furthermore, I will argue that the traces of these practices are still visible today, in the form of a popular fortune-telling tradition. Secondly, I intend to provide some information about the arrival, settlement and distribution of the Asian Diaspora. I will focus on their distribution within Mexico City. Thirdly, I will elaborate on their occupations, social status and daily life, as well as in the patterns in marriages and relations with other groups. And lastly, I will show how the guild of barbers served as an Asian immigrant reception network.

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Des de fa uns anys, des de l’EPS de la UVic, s’està duent a terme el desenvolupament d’un dispositiu electrònic que proporciona la capacitat de capturar dades sobre un niu d’ocells. El projecte e-niu, que es pot seguir a www.tutara.info/e-niu, està actualment en una fase de test., i s’ha desenvolupat sobretot la part hardware. Aquest projecte té com a objectiu principal crear un entorn web per poder gestionar les dades que s’obtenen del niu d’ocells informatitzat (e-niu). Les dades que ens arriben dels e-nius estan en un arxiu de text, i el que es pretén és que l’usuari que controla el niu, pugui fer diversos anàlisis de les dades d’aquest. A més de poder veure els resultats en diversos tipus de gràfics, també se li vol donar la opció de treure els resultats en format taula o en format Excel, un format aquest últim, molt interessant, ja que donaria a les dades una gran possibilitat de ser tractades posteriorment, com fer seleccions del tipus de dades, treure percentatges, crear altres tipus de gràfics, etc. L’altre gran objectiu és el fet de poder treballar en la creació d’un entorn web complert a nivell gairebé professional amb l’aprenentatge que això comporta, ja que s’ha aplicat la tecnologia client-servidor, és a dir, que el llenguatge de programació està dins el servidor, i quan algun usuari l’executa, el sistema només li envia la presentació en HTML. El sistema de programació que es fa servir és el de les tres capes. La capa de dades, que està formada per una base de dades relacional del tipus MySQL i és on emmagatzemarem tota la informació. La capa de programació de la que s’encarrega el llenguatge PHP, és on s’efectua tot el tractament de les dades i finalment, la capa de presentació, que és la que s’encarrega de mostrar les dades al client en el navegador mitjançant els templates de HTML.

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Trophic ecology and movements are critical issues for understanding the role of marine predators in food webs and for facing the challenges of their conservation. Seabird foraging ecology has been increasingly studied, but small elusive species, such as those forming the"little shearwater" complex, remain poorly known. We present the first study on the movements and feeding ecology of the Barolo shearwater Puffinus baroli baroli in a colony from the Azores archipelago (NE Atlantic), combining global location-sensing units, stable isotope analyses of feathers (δ13C and δ15N), stomach flushings and data from maximum depth gauges. During the chick-rearing period, parents visited their nests most nights, foraged mainly south of the colony and fed at lower trophic levels than during the non-breeding period. Squid was the most diverse prey (6 families and at least 10 different taxa), but species composition varied considerably between years. Two squid families, Onychoteuthidae and Argonautidae, and the fish family Phycidae accounted for 82.3% of ingested prey by number. On average, maximum dive depths per foraging trip reached 14.8 m (range: 7.9 to 23.1 m). After the breeding period, birds dispersed offshore in all directions and up to 2500 km from the breeding colony, and fed at higher trophic levels. Overall, our results indicate that the Barolo shearwater is a non-migratory shearwater feeding at the lowest trophic level among Macaronesian seabirds, showing both diurnal and nocturnal activity and feeding deeper in the water column, principally on small schooling squid and fish. These traits contrast with those of 3 other Azorean Procellariiformes (Cory"s shearwater Calonectris diomedea, the Madeiran storm-petrel Oceanodroma castro and Monteiro"s storm-petrel O. monteiroi), indicating ecological segregation within the Azorean seabird community.

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Ecological network patterns are influenced by diverse processes that operate at different temporal rates. Here we analyzed whether the coupled effect of local abundance variation, seasonally phenotypic plastic responses, and species evolutionary adaptations might act in concert to shape network patterns. We studied the temporal variation in three interaction properties of bird species (number of interactions per species, interaction strength, and interaction asymmetry) in a temporal sequence of 28 plant frugivore interaction networks spanning two years in a Mediterranean shrubland community. Three main hypotheses dealing with the temporal variation of network properties were tested, examining the effects of abundance, switching behavior between alternative food resources, and morphological traits in determining consumer interaction patterns. Our results demonstrate that temporal variation in consumer interaction patterns is explained by short-term variation in resource and bird abundances and seasonal dietary switches between alternative resources (fleshy fruits and insects). Moreover, differences in beak morphology are associated with differences in switching behavior between resources, suggesting an important role of foraging adaptations in determining network patterns. We argue that beak shape adaptations might determine generalist and specialist feeding behaviors and thus the positions of consumer species within the network. Finally, we provide a preliminary framework to interpret phylogenetic signal in plant animal networks. Indeed, we show that the strength of the phylogenetic signal in networks depends on the relative importance of abundance, behavioral, and morphological variables. We show that these variables strongly differ in their phylogenetic signal. Consequently, we suggest that moderate and significant phylogenetic effects should be commonly observed in networks of species interactions. Read More: http://www.esajournals.org/doi/abs/10.1890/07-1939.1

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Des de fa uns anys, des de l’EPS de la UVic, s’està duent a terme el desenvolupament d’un dispositiu electrònic que proporciona la capacitat de capturar dades sobre un niu d’ocells. El projecte e-niu, que es pot seguir a www.tutara.info/e-niu, està actualment en una fase de test., i s’ha desenvolupat sobretot la part hardware. Aquest projecte té com a objectiu principal crear un entorn web per poder gestionar les dades que s’obtenen del niu d’ocells informatitzat (e-niu). Les dades que ens arriben dels e-nius estan en un arxiu de text, i el que es pretén és que l’usuari que controla el niu, pugui fer diversos anàlisis de les dades d’aquest. A més de poder veure els resultats en diversos tipus de gràfics, també se li vol donar la opció de treure els resultats en format taula o en format Excel, un format aquest últim, molt interessant, ja que donaria a les dades una gran possibilitat de ser tractades posteriorment, com fer seleccions del tipus de dades, treure percentatges, crear altres tipus de gràfics, etc. L’altre gran objectiu és el fet de poder treballar en la creació d’un entorn web complert a nivell gairebé professional amb l’aprenentatge que això comporta, ja que s’ha aplicat la tecnologia client-servidor, és a dir, que el llenguatge de programació està dins el servidor, i quan algun usuari l’executa, el sistema només li envia la presentació en HTML. El sistema de programació que es fa servir és el de les tres capes. La capa de dades, que està formada per una base de dades relacional del tipus MySQL i és on emmagatzemarem tota la informació. La capa de programació de la que s’encarrega el llenguatge PHP, és on s’efectua tot el tractament de les dades i finalment, la capa de presentació, que és la que s’encarrega de mostrar les dades al client en el navegador mitjançant els templates de HTML.

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The recovery of vegetation in Mediterranean ecosystems after wildfire is mostly a result of direct regeneration, since the same species existing before the fire regenerate on-site by seeding or resprouting. However, the possibility of plant colonization by dispersal of seeds from unburned areas remains poorly studied. We addressed the role of the frugivorous, bird-dependent seed dispersal (seed rain) of fleshy-fruited plants in a burned and managed forest in the second winter after a fire, before on-site fruit production had begun. We also assessed the effect on seed rain of different microhabitats resulting from salvage logging (erosion barriers, standing snags, open areas), as well as the microhabitats of unlogged patches and an unburned control forest, taking account of the importance of perches as seed rain sites. We found considerable seed rain by birds in the burned area. Seeds, mostly from Olive trees Olea europaea and Evergreen pistaches Pistacia lentiscus, belonged to plants fruiting only in surrounding unburned areas. Seed rain was heterogeneous, and depended on microhabitat, with the highest seed density in the unburned control forest but closely followed by the wood piles of erosion barriers. In contrast, very low densities were found under perches of standing snags. Furthermore, frugivorous bird richness seemed to be higher in the erosion barriers than elsewhere. Our results highlight the importance of this specific post-fire management in bird-dependent seed rain and also may suggest a consequent heterogeneous distribution of fleshy-fruited plants in burned and managed areas. However, there needs to be more study of the establishment success of dispersed seeds before an accurate assessment can be made of the role of bird-mediated seed dispersal in post-fire regeneration

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The role of behavior in evolution remains controversial, despite that some ideas are over 100 years old. Changes in behavior are generally believed to enhance evolution by exposing individuals to new selective pressures and by facilitating range expansions. However, this hypothesis lacks firm empirical evidence. Moreover, behavioral changes can also inhibit evolution by hiding heritable variation from natural selection. Taking advantage of the complete phylogeny of extant birds, a new species-level measure of past diversification rate and the best existing measures of brain size (n = 1326 species), I show here that relative brain size is associated (albeit weakly) with diversification rates. Assuming that brain relative size reflects behavioral flexibility, an assumption well-supported by evidence, this finding supports the idea that behavior can enhance evolutionary diversification. This view is further supported by the discovery that the most important factor influencing diversification rates is ecological generalism, which is believed to require behavioral flexibility. Thus, behavioral changes that expose animals to a variety of environments can have played an important role in the evolution of birds.