Encontrados 10 documentos, a visualizar página 1 de 1
Assessing the impact of introduced cats on island biodiversity by combining die...
Hervias, s; Oppel, S.; Medina, F.M.; Pipa, T.; Diez, A.; Ramos, J.A.; Ruiz de Ybanez, R.; Nogales, M.Populations of feral (not owned by humans) and domestic cats Felis catus coexist in most inhabited islands, and they have similar impacts on native species. Feral cats are generally believed to vary their diet according to prey availability; however, no previous studies of diet have tested this hypothesis on insular ecosystems with a limited range of available prey. Because domestic cats kill prey independently...
Tiptoeing between restoration and invasion: seed rain into natural gaps within ...
Parejo, Sandra Hervías; Ceia, Ricardo S.; Ramos, J. A.The last remains of native laurel forest in the Azores are highly threatened by the spread of invasive plants. Because landslides are very frequent in these islands, conservation of native laurel forest requires knowledge of the patterns of bird-dispersed seed rain into forest gaps. We monitored 78 seed traps over 1 year to investigate (1) the role of perches in attracting avian dispersers into gaps, (2) tempor...
Reproductive parameters of tropical lesser noddies respond to local variations ...
Monticelli, David; Ramos, J. A.; Catry, Teresa; Pedro, Patricia; Paiva, Vitor H.Most attempts to link seabirds and climate/oceanographic effects have concerned the Atlantic and Pacific Oceans with comparatively few studies in the tropical Indian Ocean. This paper examines the reproductive response of the lesser noddy Anous tenuirostris to temporal fluctuations in oceanographic and climatic conditions using 8 years of monitoring data from Aride Island (Seychelles), tropical Western Indian O...
Polar marine biology science in Portugal and Spain: Recent advances and future ...
Xavier, José C.; Barbosa, Andrés; Agustí, Susana; Alonso-Sáez, Laura; Alvito, Pedro; Ameneiro, Julia; Ávila, Conxita; Baeta, Alexandra; Canário, JoãoPolar marine ecosystems have global ecological and economic importance because of their unique biodiversity and their major role in climate processes and commercial fisheries, among others. Portugal and Spain have been highly active in a wide range of disciplines in marine biology of the Antarctic and the Arctic. The main aim of this paper is to provide a synopsis of some of the results and initiatives undertak...
Past and present trophic position and decadal changes in diet of Yellow-legged ...
Pedro, Patricia I.; Ramos, J. A.; Neves, Verónica C.; Paiva, Vitor H.This study evaluates the trophic position of adult Yellow-legged Gulls Larus michahellis atlantis resident in the Azores archipelago in the past (1921–1928) and in the present (2009–2010), and analyses the decadal variation in the diet of breeding birds from the 1990s to the 2000s for three main colonies (Topo Islet, Baixo Islet and Mistério da Prainha). Using mixing models, we compared stable isotope signature...
Relation between climatic factors, diet and reproductive parameters of Little T...
Ramos, J. A.; Pedro, Patricia; Matos, Antonio; Paiva, Vitor H.We used 10 years of data on clutch size, egg size and diet, and 8 years of data on timing of laying on Little Terns (Sternula albifrons) breeding in Ria Formosa lagoon system, Algarve, Portugal to assess whether diet acts as an important intermediary between climatic conditions and breeding parameters. We used Generalized Linear Models to relate (1) the relative occurrence and size of the main prey species, san...
Seed dispersal networks in an urban novel ecosystem
Cruz, Joana Costa; Ramos, J. A.; Silva, Luís P.; Tenreiro, Paulo Q.; Heleno, Ruben HuttelThe conflict resulting from the expansion of human activities into natural habitats affects the structure and functioning of ecosystems. Similarly, the anthropogenic redistribution of many species all over the world affects the composition of biological communities, possibly altering their capacity to sustain key ecological functions, such as seed dispersal. Urban parks are extreme examples of such novel ecosys...
Phylogeography and genetic diversity of the Robin (Erithacus rubecula) in the A...
Rodrigues, Pedro; Lopes, Riacardo Jorge; Drovetski, Sergei V.; Reis, Sandra; Ramos, J. A.; Tristão da Cunha, ReginaWe present new insights into the phylogeography of the Robin, Erithacus rubecula, from the seven Azores Islands where it breeds, based on sequences of mitochondrial and nuclear genes from 35 individuals (five from each of the seven islands) as well as outgroup/comparison samples from Madeira, Canary Islands and Continental Western Palearctic (Europe and North Africa). To understand the level of concordance betw...
Use the backbone of your samples: fish vertebrae reduces biases associated with...
Alonso, Hany; Granadeiro, José P.; Ramos, J. A.; Catry, PauloA literature review showed that most recent conventional dietary studies of Procellariiformes have used otoliths alone to identify fish prey. Using data from a dietary study of Cory’s Shearwaters Calonectris diomedea, based on 673 regurgitates from adult birds, we quantitatively compared the contribution of otoliths and vertebrae for prey identification and quantification. By using otoliths alone, the importanc...
Conservation of Puffinus species in the Azores
Groz, Maria Pitta; Monteiro, L. R.; Pereira, J. C.; Silva, A. G.; Ramos, J. A.Historical data on the Azores breeding Puffinus species is reviewed through the analysis of historical chronicles from the 16th and 17th century. The seabird populations of the Azores suffered dramatic declines following the colonisation of the islands mainly due to habitat destruction, the introduction of predators and direct human exploitation. Inventories of all the seabirds populations became available only...
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