Search results for "ONG"
showing 10 items of 9299 documents
Endocrine correlates of the breeding asynchrony between two Corsican populations of Blue tits (Parus caeruleus)
2004
International audience; Analyses of the development of the reproductive system in seasonally breeding birds in the framework of long-term ecological studies are rare. Here, we present the Wrst results of such a study in two Corsican populations of a European passerine bird, the blue tit (Parus caeruleus). The two study populations occupy diVerent oak habitats and are separated by only 25km. Despite their close proximity, they show a one-month diVerence in onset of egg laying, even after controlling for altitude. This micro-geographic diVerence in breeding date appears adaptive because both study populations raise chicks when food is most plentiful. In our study, males reached their maximum …
Egalitarian mixed-species bird groups enhance winter survival of subordinate group members but only in high-quality forests
2020
AbstractOnly dominant individuals have unrestricted access to contested resources in group-living animals. In birds, subordinates with restricted access to resources may respond to intragroup contests by acquiring extra body reserves to avoid periods of food shortage. In turn, higher body mass reduces agility and increases predation and mortality risk to subordinates. Birds often live in hierarchically organized mixed-species groups, in which heterospecific individuals are considered to substitute for conspecifics as protection against predators at a significantly reduced competition cost. Crested tits (Lophophanes cristatus) and willow tits (Poecile montanus) form mixed-species groups duri…
Genetic correlation between resistance to oxidative stress and reproductive life span in a bird species.
2010
Evolutionary theories propose that aging is the result of a trade-off between self-maintenance and reproduction, and oxidative stress may play a crucial role in such a trade-off. Phenotypic manipulations have revealed that a high investment in reproduction leads to a decline in the organism's resistance to oxidative stress, which could in turn accelerate aging. Here, by using quantitative genetic analyses as a tool to disentangle genetic effects from phenotypic variances, the relationship between resistance to oxidative stress at sexual maturity and two key reproductive life-history traits (i.e., number of breeding events during life and age at last reproduction) was analyzed in cross-foste…
Mediterranean sponges from shallow subtidal rocky reefs: Cystoseira canopy vs barren grounds
2018
Abstract Porifera richness was investigated in Cystoseira canopies vs barren grounds considering different substrates at 6 areas in the Central-Western Mediterranean Sea. In total 31 sponge taxa were recorded at 2–7 m depth and the sponge community structure and composition were characterized by a notably low richness with 25 taxa in the Cystoseira forest and 15 in the barren area. As for the sponge habitus, the massive sponges were dominant in both facies, whereas encrusting, and cavity dwelling sponges were found in higher numbers in the Cystoseira forest. Results revealed that rocky substrata seem to play a key role in driving the sponge community composition and diversity in both facies…
First assessment of the rose shrimp, Parapenaeus longirostris (Lucas, 1846) in the central Mediterranean
1995
Abstract Between June 1989 and May 1990 a 1 year programme based on commercial samples and statistics was carried out to assess Parapenaeus longirostris in the Sicilian Channel (Central Mediterranean), since most trawl-fishing occurs outside the area currently covered by trawl surveys of the National Research Council Institute based in Mazara del Vallo. Fishing takes place on three distinct grounds, where three different sub-stocks belonging to the same population could be identified based on length and maturity data. Length-based methods allowed calculation of all parameters needed to fit Beverton and Holt's (1957) and Thompson and Bell's (1934) models, while natural mortality could be est…
Grafting affects yield and phenolic profile of Solanum melongena L. landraces
2016
Abstract The influence of grafting on agronomical and qualitative characteristics of four Sicilian eggplant landraces was investigated. Grafted and ungrafted plants were compared in the open field in the northern coast of Sicily. Solanum torvum seedlings were used as rootstock. Regardless of genotypes tested, grafting significantly increased total fruit production, marketable production, and number of marketable fruits, but did not affect weight of marketable fruits and waste production. Landrace 2 (Sciacca), with black epidermal tissue and pyriform fruit shape, when grafted onto S. torvum not only gave a higher yield performance than ungrafted plants, but also showed a higher phenolic anti…
Solanum aethiopicum gr. gilo and Its Interspecific Hybrid with S. melongena as Alternative Rootstocks for Eggplant: Effects on Vigor, Yield, and Frui…
2019
Grafting is generally considered effective in ameliorating vegetable crop tolerance to biotic and abiotic stresses. The use of interspecific hybrid as rootstock for eggplant may represent a valid alternative approach to enhance eggplant performance. However, studies on the effects of different rootstocks on eggplant plant vigor, yield, and fruit quality traits often show conflicting results. Thus, an experiment was performed in two spring&ndash
Classification of steppe vegetation in the eastern Pamir Alai and southwestern Tian-Shan Mountains (Tajikistan, Kyrgyzstan)
2018
Aims: To complete the syntaxonomical scheme for the steppe vegetation of the montane and alpine zones in the Pamir Alai and southwestern Tian-Shan Mountains in Tajikistan and Kyrgyzstan with some remarks on its environmental predictors. Location: Tajikistan and Kyrgyzstan. Methods: A total of 274 relevés were sampled in 2016–2017 using the seven-degree cover-abundance scale of Braun-Blanquet. They were classified with modified TWINSPAN with cut-off levels of 0%, 5%, 10% and 25% and total inertia as a measure of cluster heterogeneity. Diagnostic species were identified using the phi coefficient as a fidelity measure. Detrended correspondence analysis (DCA) and canonical correspondence analys…
Bayesian analysis improves experimental studies about temporal patterning of aggression in fish.
2017
Made available in DSpace on 2018-12-11T17:15:13Z (GMT). No. of bitstreams: 0 Previous issue date: 2017-12-01 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) This study aims to describe a Bayesian Hierarchical Linear Model (HLM) approach for longitudinal designs in fish's experimental aggressive behavior studies as an alternative to classical methods In particular, we discuss the advantages of Bayesian analysis in dealing with combined variables, non-statistically significant results and required sample size using an experiment of angelfish (Pterophyllum scalare) species as case study. Groups of 3 individuals were subjected to daily observations recorded for 10 min durin…
Reappraisal of ‘chronospecies' and the use of Arvicola (Rodentia, Mammalia) for biochronology.
2008
13 pages; International audience; The water vole, genus Arvicola, is characterised by a broad geographic distribution throughout Europe and is widespread during the late Middle and Upper Pleistocene. This genus is used as a major biostratigraphic tool within the Quaternary. Specific determinations using the Schmelzband-Differenzierung-Quotient or SDQ have identified many chronospecies within the fossil species Arvicola cantiana (Hinton, 1910). As SDQ calculation remains limited, this study reappraises the Arvicola genus in terms of morphodiversity and morphospace using outline analysis which takes into account the tooth as a whole. Outline analysis suggests that one single species of Arvico…