Search results for "010601 ecology"
showing 10 items of 69 documents
From arctic lemmings to adaptive dynamics: Charles Elton's legacy in population ecology.
2001
We shall examine the impact of Charles S. Elton's 1924 article on periodic fluctuations in animal populations on the development of modern population ecology. We argue that his impact has been substantial and that during the past 75 years of research on multi-annual periodic fluctuations in numbers of voles, lemmings, hares, lynx and game animals he has contributed much to the contemporary understanding of the causes and consequences of population regulation. Elton was convinced that the cause of the regular fluctuations was climatic variation. To support this conclusion, he examined long-term population data then available. Despite his firm belief in a climatic cause of the self-repeating …
Coexistence and resource competition.
2000
How large numbers of species coexist on a seemingly limited number of different resources is a classic problem in ecology1, and attempts have been made to solve it experimentally. But we are not convinced that Huisman and Weissing's2 proposal to add non-stationary dynamics in species abundance to the list of possible explanations offers any new insight into this biodiversity enigma.
Paisaje y nacionalismo en el primer franquismo
2016
Assuming the theoretical idea widely developed by Human Geography that landscapes are cultural constructions with the capacity to become symbolic elements within nationalist discourses, this article explores the context of early Francoism. The aim of these pages is to analyze landscape sensibility as well as the landscape idea developed by the francoist nationalist discourse by trying to draw out three inherent elements in it: first of all, following Oliver Zimmer’s work, the nationalization of nature, this is to say, the consideration that nature expresses the community’s myths, events or memories; secondly, the naturalisation of the nation, that projects upon landscapes the capacity to de…
'Historia y cine. La construcción del pasado a través de la ficción', de Mónica Bolufer, Juan Gomis y Telesforo Hernández(eds.)
2016
Resena critica de: Bolufer, Monica; Gomis, Juan y Hernandez M. Telesforo (eds.) (2015), Historia y cine. La construccion del pasado a traves de la ficcion , Institucion Fernando el Catolico, Zaragoza. ISBN: 9788499113722, 216 pags.
Protist predation can select for bacteria with lowered susceptibility to infection by lytic phages
2015
Background: Consumer-resource interactions constitute one of the most common types of interspecific antagonistic interaction. In natural communities, complex species interactions are likely to affect the outcomes of reciprocal co-evolution between consumers and their resource species. Individuals face multiple enemies simultaneously, and consequently they need to adapt to several different types of enemy pressures. In this study, we assessed how protist predation affects the susceptibility of bacterial populations to infection by viral parasites, and whether there is an associated cost of defence on the competitive ability of the bacteria. As a study system we used Serratia marcescens and i…
Long-term changes in the breeding period diet of Bonelli
2019
Context Dietary analyses are essential to achieve a better understanding of animal ecology. In the case of endangered species, assessing dietary requirements is crucial to improve their management and conservation. The Bonelli’s eagle (Aquila fasciata) has experienced a severe decline throughout its breeding range in Europe and, in Italy, fewer than 50 pairs remain, and only in Sicily. This species is subject to major threats, including changes in landscape composition and, consequently, prey availability, which is further aggravated by the occurrence of viral diseases in the case of rabbits. Aims To provide current data on the diet of the Bonelli’s eagle in Sicily during the breeding peri…
Interactions between environmental variability and immigration rate control patterns of species diversity
2006
Abstract Theories focussing on local competition processes predict that species diversity is maximised with high-frequency environmental variability or alternatively with intermediate frequencies. The models coupling regional processes to local explanations of diversity patterns predict that the immigration rate from a regional species pool can strongly increase diversity. However, the interaction between local and regional processes in temporally fluctuating environment has received little attention. We explored in a simulation study how the patterns of species diversity are affected by the frequency spectrum of stochastic environmental variations and density independent immigration rate i…
Stable isotopes reveal differences in diet among reed bunting subspecies that vary in bill size
2017
Reed bunting Emberiza schoeniclus subspecies vary considerably in bill size and shape and seem to be at an early stage of speciation, in which bill might be indirectly causing reproductive isolation. Hence, we evaluated whether bill size, as well as age and sex, are associated with foraging niche in three west European subspecies of reed bunting: the thin-billed schoeniclus, the intermediate-billed lusitanica and the thick-billed witherbyi. Blood sampling was undertaken at three sites in southwest Europe during the winter (when these subspecies co-occur), and stable isotope analyses (carbon and nitrogen) were performed to assess their foraging niches. Stable isotope analyses of potential fo…
Habitat ecology of the smooth snake Coronella austriaca and its reptilian prey in the degraded bog with implications for artificial refuge surveys
2016
AbstractDiet preferences of the smooth snake (Coronella austriaca) being still controversial, we studied the overlap between its habitat and that of its potential reptilian prey species using the artificial refuge (ATR) method. The discriminant function analysis revealed that part of the smooth snake’s habitat niche is unused by one of its prey species – Zootoca vivipara. The smooth snake was recorded more often in places with high density of individuals of another lizard species – Anguis fragilis. Occasional data on snake diets supported the assumption that the latter species is a very important food item for the smooth snake in the study area. Our study estimated the minimum number of tim…
Onset of natal dispersal in Peregrine Falcon from Mediterranean islands (Italy)
2018
Abstract Basic information on natal dispersal of Peregrine Falcons is virtually lacking in Europe, despite increased attention on this species, and the sensitivity of this stage in the Peregrines’ life history. In this study, we collected satellite telemetry data during the onset of natal dispersal of 19 Peregrine Falcons tagged in Sicily and the Aeolian archipelago (Italy). We divided the onset of dispersal into the following 3 periods: post-fledging dependence period (PFDP), wandering, and wintering. PFDP lasted on average 47±16 days, during which young peregrines moved very little (0.167 km), and explored small areas (0.226 km2) far from the nest cliff, and showed no sex differences. The…