Search results for "Common"
showing 10 items of 20610 documents
Bachelor groups form due to individual choices or environmental disrupters in African striped mice
2021
International audience; In several mammal species, bachelor groups occur as a regular life history stage between dispersal and becoming the breeding male of a multi-female group. However, it is rarely investigated how such groups come into existence and how males that choose this strategy differ in life history traits from other males. Males of the socially flexible African striped mouse Rhabdomys pumilio have been historically reported to adopt one of three alternative tactics, i.e., small group-living philopatric males, intermediate solitary living roaming males, or large group-living territorial males. Here, we describe for the first time, bachelors as a fourth male tactic. Using long-te…
Exploratory behaviour is not related to associative learning ability in the carabid beetle Nebria brevicollis.
2020
Abstract Recently, it has been hypothesised that as learning performance and animal personality vary along a common axis of fast and slow types, natural selection may act on both in parallel leading to a correlation between learning and personality traits. We examined the relationship between risk-taking, exploratory behaviour and associative learning ability in carabid beetle Nebria brevicollis females by quantifying the number of trials individuals required to reach criterion during an associative learning task (‘learning performance’). The associative learning task required the females to associate odour and direction with refugia from light and heat in a T-maze. Further, we assessed lea…
Experimental size-selective harvesting affects behavioral types of a social fish
2019
In most fisheries, larger fish experience substantially higher mortality than smaller fish. Body length, life history, and behavioral traits are often correlated, such that fisheries-induced changes in size or life history can also alter behavioral traits. However, empirical evidence regarding how size-selective harvesting alters the evolution of behavioral traits in exploited stocks is scarce. We used experimental lines of Zebrafish Danio rerio that were exposed to positively size-selective, negatively size-selective, or random harvest over five generations. Our aim was to investigate whether simulated fishing changed the mean personality of the surviving females five generations after ini…
Competition for resources is ameliorated by niche differentiation between Solidago virgaurea life-history stages in the Arctic
2016
Aims Competition has been shown to modify the niche breadth of coexisting species, but within-species interactions have received little attention. Establishing small juvenile individuals and established, larger, sexually reproducing adult individuals represent two life-history stages within species. We investigated the nitrogen and carbon resource use of adult and juvenile individuals and similarity of symbiotic fungal community composition in these two plant life stages. We used the plant Solidago virgaurea growing in a simplified system in the low Arctic as model species. Methods Isotopic signatures (foliar δ15N and foliar δ13C) were analysed to characterize nitrogen acquisition and water…
Analysis of Hemolymph Ecdysteroids in the Female Earwig: Labidura riparia
1991
International audience; The nature of hemolymph ecdysteroids was analyzed by high performance liquid chromatography-radioimmunoassay, during the two main phases of the reproductive cycles of Labidura riparia. 20-hydroxyecdysone and ecdysone were present together with polar and apoiar products.Changes in the ecdysone/20-hydroxyecdysone ratio were evidenced according to the ovarian development. During natural (feeding and sexual phase of the cycle) or induced ovarian development, an increase of the ratio occurred whereas, during ovarian rest (fasting and/or parental phase), a significant decrease was observed.Up to 40 days after ovariectomy, immunoreactive compounds were observed in the hemol…
Lateralization of complex behaviours in wild greater flamingos.
2018
8 pages; International audience; Lateralization refers to the preferential use of one side of the body to perform certain tasks, often as a consequence of the specialization of cerebral hemispheres. Individuals may benefit from lateralization if it allows them to perform complex tasks simultaneously. Studies on laterality further suggest that sex and age can influence the extent of lateralization. However, most studies on lateralization have been performed on captive individuals, exposed to simplified environments and expressing limited behavioural repertoire. Here, we evaluated behavioural lateralization in the greater flamingo, Phoenicopterus roseus, through observations of wild individua…
Is mate choice in Drosophila males guided by olfactory or gustatory pheromones ?
2010
International audience; Drosophila melanogaster flies use both olfactory and taste systems to detect sex pheromones and select the most suitable mate for reproduction. In nature, flies often face multiple potential partners and should have an acute sensory ability to discriminate between different pheromonal bouquets. We investigated both the pheromones and the chemosensory neurons influencing Drosophila mate choice. We measured various courtship traits in single tester males simultaneously presented with two target male and/or female flies carrying different pheromonal bouquets (pairs of control flies of the same or different sex, same-sex target pairs of pheromonal variant strains). The c…
Potential for managing life history diversity in a commercially exploited intermediate predator, the goldsinny wrasse (Ctenolabrus rupestris)
2019
Abstract Small-bodied wrasse species are important for structuring coastal marine ecosystems but are also increasingly harvested as parasite cleaners on farmed salmon. Identifying management regulations that will support long-term sustainability of wrasse fisheries is challenging, because there is still limited knowledge about the impacts of fisheries on the demography of these intermediate predators in their natural environments. To this end, we studied individual growth histories of goldsinny wrasse (Ctenolabrus rupestris) at a fine spatial scale across replicated marine protected areas (MPAs) and areas open to commercial harvesting on the Norwegian coast. The MPAs were established 1–7 ye…
Adaptation to climate change of the French wine industry: a systemic approach – Main outcomes of the project LACCAVE
2018
Présenté au 12. Congreso Internacional Terroir; Taking into account the major economical role and specificities of the French wine industry, adaptation to climate change is a very challenging issue. In 2011, 23 research teams launched a systemic and multidisciplinary program to analyze the impacts from the vine to the region, to define adaptation strategies combining technical, spatial and organizational options and to evaluate the perception by the actors and consumers of climate change issues. Thermal variability was studied at local scale to develop high resolution atmospheric models which better simulate future climate trends. Impacts on growth/developmental conditions and vine response…
Eutrophic status influences the impact of pesticide mixtures and predation on Daphnia pulex populations
2021
Abstract Pesticides, nutrients, and ecological stressors such as competition or predation co‐occur in freshwater ecosystems impacted by agriculture. The extent to which combinations of these stressors affect aquatic populations and the role of nutrients availability in modulating these responses requires further understanding. In this study, we assessed how pesticides affecting different taxonomic groups and predation influence the response of Daphnia pulex populations under different trophic conditions. An outdoor experiment was designed following a factorial design, with the insecticide chlorpyrifos, the herbicide diuron, and the predation by Notonecta sp. individuals as key stressors. Th…