Search results for "POPULATION DYNAMICS"
showing 10 items of 281 documents
Interactive effects of past and present environments on overwintering success-a reciprocal transplant experiment.
2011
Life-history traits are influenced by environmental factors throughout the lifespan of an individual. The relative importance of past versus present environment on individual fitness, therefore, is a relevant question in populations that face the challenge of temporally varying environment. We studied the interacting effects of past and present density on body mass, condition, and survival in enclosure populations of the bank vole (Myodes glareolus) using a reciprocal transplant design. In connection with the cyclic dynamics of natural vole populations, our hypothesis was that individuals born in low-density enclosures would do better overwintering in low-density enclosures than in high-den…
Combining Sequence Analysis and Hidden Markov Models in the Analysis of Complex Life Sequence Data
2018
Life course data often consists of multiple parallel sequences, one for each life domain of interest. Multichannel sequence analysis has been used for computing pairwise dissimilarities and finding clusters in this type of multichannel (or multidimensional) sequence data. Describing and visualizing such data is, however, often challenging. We propose an approach for compressing, interpreting, and visualizing the information within multichannel sequences by finding (1) groups of similar trajectories and (2) similar phases within trajectories belonging to the same group. For these tasks we combine multichannel sequence analysis and hidden Markov modelling. We illustrate this approach with an …
Elucidating geological and biological processes underlying the diversification of Sulawesi tarsiers.
2009
Because of their exceptionally long independent evolution, a range diminution of their Eocene relatives, and a remarkable subsequent diversification in Southeast Asia, tarsiers are of particular importance to evolutionary primatologists. Little is known, however, on the processes shaping the radiation of these small enigmatic primates—especially on the Indonesian island of Sulawesi, their center of endemism. Geological reconstructions and progress in applying DNA sequence information to divergence dating now provide us with the tools and background to comprehend tarsier dispersal. Here, we describe effects of plate-tectonic movements, Pleistocene sea level changes, and hybridization on the…
Dynamics of three interacting species in single compartment and in spatially extended system by moment equations
2008
Real ecosystems are influenced by random fluctuations of environmental parameters, such as temperature, food resources, migrations, genetic changes. This caused, during last decades, an increasing interest on the role played by the noise in population dynamics. In systems governed by nonlinear dynamics the presence of noise sources can give rise to counterintuitive phenomena like stochastic resonance, noise enhanced stability, resonant activation, noise delayed extinction. Therefore, the stability of biological systems in the presence of noise sources has become one of the most relevant topics both in experimental and theoretical investigations on complex systems. In this work we consider t…
Diversifying crop rotations with temporary grasslands: potentials for weed management and farmland biodiversity
2010
Fruchtfolgen können dazu dienen, die kontinuierliche Selektion von Unkrautarten zu verhindern, die an eine bestimmte Kultur angepasst sind. Dies könnte dem Unkrautmanagement, der Einsparung von Herbiziden, und der Biodiversität dienen. Heutige, sehr einfache Furchtfolgen könnten durch mehrjährige Futterkulturen diversifiziert werden. Die Einflüsse solcher mehrjähriger Kulturen auf Unkräuter wurden in vier Ansätzen untersucht : 1) Vegetationsaufnahmen auf 632 Feldern in Westfrankreich zeigten, dass die Unkrautzusammensetzung zwischen mehrjährigen Futterkulturen und einjährigen Kulturen stark variiert. Der Vergleich von Feldern vor, während und nach mehrjährigen Futterkulturen legte nahe, das…
Nuovi dati sull’espansione dell’occhione Burhinus oedicnemus in Sicilia. Una riflessione sulla citizen science
2023
New data on the expansion of the Eurasian Thick-knee Burhinus oedicnemus in Sicily. A consideration of citizen science.In this work, we collected records of Eurasian Thick-knee observa-tions in Sicily by using scientific literature, citizen science programs, and social networks as data sources. The aims of this work is creat-ing a complete and up-to-date dataset, which also includes the authors’ targeted research in the field. As compared with records previously reported in literature, the data collected here, which cover the last fif-teen years, show a clear expansion trend for the Eurasian Thick-kneein Sicily. About one third of these new records come from Facebook groups dedicated to bio…
AGGIORNAMENTO SULLA DISTRIBUZIONE DEL SUCCIACAPRE Caprimulgidae) IN SICILIA CAPRIMULGUS EUROPAEUS (Aves
2021
Caprimulgus europaeus In recent years Update on the distribution of breeding Nightjar in Sicily. there have been numerous observations of Nightjar in areas where it had never previously been observed. In some cases the reason may be a deeper exploration, but in other cases the possible explanation is the expansion of the species. However, it is quite interesting the change in the habitat by this species. The present paper provides an update of its status based on data collected in the fifteen years following the publication of the last Sicilian Atlas of breeding birds.
ESPANSIONE DELLA RONDINE MONTANA PTYONOPROGNE RUPESTRIS (SCOPOLI) IN SICILIA (Aves Hirundinidae)
2021
Expansion of the Eurasian Crag Martin Ptyonoprogne rupestris (Scopoli) in Sicily (Aves Hirun dinidae). Data collected during the last fifteen years on the distribution of the Eurasian Crag Martin in Sicily and the comparison with those recorded in literature show an expansion trend for this species. While in the newly colonized areas the nesting sites have been observed mainly on natural habitats, where its occurrence was previously recorded the species shows and adaptation to exploit also anthropogenic habitats, such as buildings or other infrastructures.
CHECK-LIST DEGLI UCCELLI DELLA R.N.O. “SALINE DI TRAPANI E PACECO” CON LISTA COMMENTATA DEI NON PASSERIFORMES
2018
Update of the checklist of the birds of the Nature Reserve “Saline di Trapani e Paceco” (Sicily). The present work provides an update to the checklist of birds of the “Saline di Trapani e Paceco” published nine years ago by IENTILE (2008). The overall number of bird species increased from 209 to the current value of 229. The present work also includes a quantitative estimate of the breeding and wintering species. A table, detailing the number of individuals of each species present for each month of the year at the Saline di Trapani and Paceco, is included. This work aims at underscoring the importance of the Saline as an Important Bird Area (IBA), as a key area for the migration pathways of…
Antennal lobe representations are optimized when olfactory stimuli are periodically structured to simulate natural wing beat effects
2014
Animals use behaviors to actively sample the environment across a broad spectrum of sensory domains. These behaviors discretize the sensory experience into unique spatiotemporal moments, minimize sensory adaptation, and enhance perception. In olfaction, behaviors such as sniffing, antennal flicking, and wing beating all act to periodically expose olfactory epithelium. In mammals, it is thought that sniffing enhances neural representations; however, the effects of insect wing beating on representations remain unknown. To determine how well the antennal lobe produces odor-dependent representations when wing beating effects are simulated, we used extracellular methods to record neural units an…