Recursos de colección

UTL Repository Universidade Técnica de Lisboa (32.085 recursos)

O Repositório Institucional da Universidade Técnica de Lisboa desenvolvido no âmbito do projecto RCAAP. Este repositório destina-se a recolher, preservar e disponibilizar o acesso às publicações científicas e didácticas de seis: Escolas da UTL: Faculdade de Medicina Veterinária, Instituto Superior de Agronomia, Instituto Superior de Economia e Gestão, Instituto Superior de Ciências Sociais e Políticas , Faculdade de Motricidade Humana, Faculdade de Arquitectura. O Instituto Superior Técnico, igualmente Escola Da UTL, tem repositório independente.

Mostrando recursos 1 - 15 de 15

  1. Match between soaring modes of black kites and fine-scale distribution on updrafts

    Santos, Carlos D.; Hanssen, Frank; Muñoz, António-Román; Onrubia, A.; Wikelski, Martin; May, Roel; Silva, João P.
    Understanding how soaring birds use updrafts at small spatial scales is important to identify ecological constraints of movement, and may help to prevent conflicts between wind-energy development and the conservation of wildlife. We combined high-frequency GPS animal tracking and fine-spatial-scale uplift modelling to establish a link between flight behaviour of soaring birds and the distribution of updrafts. We caught 21 black kites (Milvus migrans) and GPS-tracked them while flying over the Tarifa region, on the Spanish side of the Strait of Gibraltar. This region has a diverse topography and land cover, favouring a heterogeneous updraft spatial distribution. Bird tracks were segmented and classified into flight modes from...

  2. Fungal infestation boosts fruit aroma and fruit removal by mammals and birds

    Peris, Josep E.; Rodriguez, Ana; Peña, Leandro; Fedriani, José Maria
    For four decades, an influential hypothesis has posited that competition for food resources between microbes and vertebrates selects for microbes to alter these resources in ways that make them unpalatable to vertebrates. We chose an understudied cross kingdom interaction to experimentally evaluate the effect of fruit infection by fungi on both vertebrate (mammals and birds) fruit preferences and on ecologically relevant fruit traits (volatile compounds, toughness, etc). Our well-replicated field experiments revealed that, in contrast to previous studies, frugivorous mammals and birds consistently preferred infested over intact fruits. This was concordant with the higher level of attractive volatiles (esters, ethanol) in infested fruits. This investigation suggests that...

  3. Dispersal ability determines the scaling properties of species abundance distributions: a case study using arthropods from the Azores

    Borda-de-Água, Luís; Whittaker, Robert J.; Cardoso, Pedro; Rigal, François; Santos, Ana M.C.; Amorim, Isabel R.; Parmakelis, Aristeidis; Triantis, Kostas A.; Pereira, Henrique M.; Borges, Paulo A.
    Species abundance distributions (SAD) are central to the description of diversity and have played a major role in the development of theories of biodiversity and biogeography. However, most work on species abundance distributions has focused on one single spatial scale. Here we used data on arthropods to test predictions obtained with computer simulations on whether dispersal ability influences the rate of change of SADs as a function of sample size. To characterize the change of the shape of the SADs we use the moments of the distributions: the skewness and the raw moments. In agreement with computer simulations, low dispersal ability species generate a hump for...

  4. Conservation status of a recently described endemic land snail, Candidula coudensis, from the Iberian Peninsula

    Moreira, Francisco; Calado, Gonçalo; Dias, Susana
    Research Article

  5. Estimation of productivity in pine and oak forests in northern Portugal using Biome-BGC

    Nunes, Leónia; Gower, Stith T.; Peckham, Scott D.; Magalhães, Marco; Lopes, Domingos; Rego, Francisco Castro
    Studies about the productivity of forest ecosystems help to quantify sequestered carbon and provide data that are used in forest management. Forests in northern Portugal are an important economic resource, but their productivity in scenarios of future climate change is not yetwell understood. The objectives of this study were to evaluate and compare simulated net primary production (NPP) andNPPbased onmeasured data of twotree species located in the Vila Real district forests, pine (Pinus pinaster Aiton) and oak (Quercus pyrenaica Willd.) and assess their simulatedNPPin diverse climate conditions, including future climate scenariosandincreasing atmospheric CO2 concentrations. An ecosystem process model, Biome-BGC, which simulates carbon, nitrogen and water cycles...

  6. Mixed effects of long-term conservation investment in Natura 2000 farmland

    Santana, Joana; Reino, Luís; Stoate, Chris; Borralho, Rui; Carvalho, Carlos Rio; Schindler, Stefan; Moreira, Francisco; Bugalho, Miguel N.; Ribeiro, Paulo Flores; Santos, José Lima; Vaz, Alexandre; Morgado, Rui; Porto, Miguel; Beja, Pedro
    Evaluating the effectiveness of conservation funding is crucial for correct allocation of limited resources. Here we used bird monitoring data to assess the effects of long-term conservation investment in a Natura 2000 (N2000) bird protection area (PA), which during two decades benefited from protection regulations, conservation projects, and agri-environment schemes. Variation between 1995–1997 and 2010–2012 in richness and abundance of flagship (Otis tarda, Tetrax tetrax, and Falco naumanni) and specialized fallow field species were more favorable (i.e., increased more or declined less) inside the PA than in a nearby control area. However, the reverse was found for total bird species, farmland, ground-nesting and steppe species, species associated to ploughed fields,...

  7. Modeling stream fish distributions using interval-censored detection times

    Ferreira, Mário; Filipe, Ana Filipa; Bardos, David C.; Magalhães, Maria Filomena; Beja, Pedro
    Controlling for imperfect detection is important for developing species distribution models (SDMs). Occupancy-detection models based on the time needed to detect a species can be used to address this problem, but this is hindered when times to detection are not known precisely. Here, we extend the time-to-detection model to deal with detections recorded in time intervals and illustrate the method using a case study on stream fish distribution modeling. We collected electrofishing samples of six fish species across a Mediterranean watershed in Northeast Portugal. Based on a Bayesian hierarchical framework, we modeled the probability of water presence in stream channels, and the probability of species occupancy conditional on water...

  8. Predicting bat distributions and diversity hotspots in southern Africa

    Cooper-Bohannon, Rachael; Rebelo, Hugo; Jones, Gareth; Cotterill, Fenton; Monadjem, Ara; Schoeman, M.Corrie; Taylor, Peter; Park, Kirsty
    Species distribution models were used to predict bat species richness across southern Africa and to identify potential drivers of these spatial patterns. We also identified species richness within each biotic zone and the distributions of species considered of high conservation priority. We used this information to highlight conservation priorities for bats in southern Africa (defined here as between the latitudes of 8° S, slightly north of Zambia, to the southern tip of Africa 34° S, an area of approximately 9781840 km2). We used maximum entropy modelling (Maxent) to model habitat suitability for 58 bat species in order to determine the key eco-geographical variables influencing their distributions. The...

  9. High unexpected genetic diversity of a narrow endemic terrestrial mollusc

    Madeira, Pedro M.; Chefaoui, Rosa M.; Cunha, Regina L.; Moreira, Francisco; Dias, Susana; Calado, Gonçalo; Castilho, Rita
    The Iberian Peninsula has an extensive record of species displaying strong genetic structure as a result of their survival in isolated pockets throughout the Pleistocene ice ages. We used mitochondrial and nuclear sequence data to analyze phylogeographic patterns in endemic land snails from a valley of central Portugal (Vale da Couda), putatively assigned to Candidula coudensis, that show an exceptionally narrow distributional range. The genetic survey presented here shows the existence of five main mitochondrial lineages in Vale da Couda that do not cluster together suggesting independent evolutionary histories. Our results also indicate a departure from the expectation that species with restricted distributions have low genetic variability. The putative...

  10. Wired: impacts of increasing power line use by a growing bird population

    Moreira, Francisco; Encarnação, Vitor; Rosa, Gonçalo; Gilbert, Nathalie; Infante, Samuel; Costa, Julieta; D'Amico, Marcello; Martins, Ricardo C.; Catry, Inês
    Power lines are increasingly widespread across many regions of the planet. Although these linear infrastructures are known for their negative impacts on bird populations, through collision and electrocution, some species take advantage of electricity pylons for nesting. In this case, estimation of the net impact of these infrastructures at the population level requires an assessment of trade-offs between positive and negative impacts. We compiled historical information (1958–2014) of the Portuguese white stork Ciconia ciconia population to analyze long-term changes in numbers, distribution range and use of nesting structures. White stork population size increased 660% up to 12000 breeding pairs between 1984 and 2014. In the same period,...

  11. Regional bans on wild-bird trade modify invasion risks at a global scale

    Cardador, Laura; Lattuada, Matteo; Strubbe, Diederik; Tella, José L.; Reino, Luís; Figueira, Rui; Carrete, Martina
    Wildlife trade is currently the most important and increasing source of vertebrate invasive species. However, exhaustive analyses of potential side effects of trade regulations on this pathway of introduction are lacking. We addressed this by combining environmental niche models and global trade data on parrots (Psittaciformes), one of the most widely traded and worldwide invasive taxa. We used the wild bird trade bans of United States (1992) and Europe (2005) as case-studies. Results showed that regional bans can generate geographic redirections in trade, with important consequences on worldwide invasion risk. While the amount of parrots traded internationally remained largely constant, changes in trade destination occurred. Consequently, the world surface predicted...

  12. Combined effects of landscape composition and heterogeneity on farmland avian diversity

    Santana, Joana; Reino, Luís; Stoate, Chris; Moreira, Francisco; Ribeiro, Paulo F.; Santos, José L.; Rotenberry, John T.; Beja, Pedro
    Conserving biodiversity on farmland is an essential element of worldwide efforts for reversing the global biodiversity decline. Common approaches involve improving the natural component of the landscape by increasing the amount of natural and seminatural habitats (e.g., hedgerows, woodlots, and ponds) or improving the production component of the landscape by increasing the amount of biodiversity-friendly crops. Because these approaches may negatively impact on economic output, it was suggested that an alternative might be to enhance the diversity (compositional heterogeneity) or the spatial complexity (configurational heterogeneity) of land cover types, without necessarily changing composition. Here, we develop a case study to evaluate these ideas, examining whether managing landscape composition or heterogeneity,...

  13. Discussing landscape compositional scenarios generated with maximization of non-expected utility decision models based on weighted entropies

    Casquilho, José Pinto; Rego, Francisco Castro
    Concept Paper

  14. The role of conservative versus innovative nesting behavior on 25-year population expansion of an avian predator

    Dias, Andreia; Palma, Luís; Carvalho, Filipe; Neto, Dora; Real, Joan; Beja, Pedro
    Species ranges often change in relation to multiple environmental and demographic factors. Innovative behaviors may affect these changes by facilitating the use of novel habitats, although this idea has been little explored. Here, we investigate the importance of behavior during range change, using a 25-year population expansion of Bonelli’s eagle in southern Portugal. This unique population is almost exclusively tree nesting, while all other populations in western Europe are predominantly cliff nesting. During 1991–2014, we surveyed nest sites and estimated the year when each breeding territory was established. We approximated the boundaries of 84 territories using Dirichlet tessellation and mapped topography, land cover, and the density of human infrastructures in...

  15. Do extended incubation recesses carry fitness costs in two cavity-nesting birds ?

    Bueno-Enciso, Javier; Barrientos, Rafael; Ferrer, Esperanza S.; Sanz, Juan José
    Because extended incubation recesses, where incubating songbirds are away from nests for periods much longer than usual, occur infrequently, they have been treated as outliers in most previous studies and thus overlooked. However, egg temperatures can potentially fall below the physiological zero temperature during extended recesses, potentially affecting developing embryos. As such, evaluating extended recesses in an ecological context and identifying their possible fitness effects are important. With this aim, we used iButton data loggers to monitor the incubation behavior of female Blue Tits (Cyanistes caeruleus) and Great Tits (Parus major) during two breeding seasons in central Spain. We classified incubation recesses as extended if they...

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