Search results for " Behaviour"
showing 10 items of 1096 documents
Quorum Sensing and Density-Dependent Dispersal in an Aquatic Model System
2012
International audience; Many organisms use cues to decide whether to disperse or not, especially those related to the composition of their environment. Dispersal hence sometimes depends on population density, which can be important for the dynamics and evolution of subdivided populations. But very little is known about the factors that organisms use to inform their dispersal decision. We investigated the cues underlying density-dependent dispersal in interconnected microcosms of the freshwater protozoan Paramecium caudatum. In two experiments, we manipulated (i) the number of cells per microcosm and (ii) the origin of their culture medium (supernatant from high-or low-density populations). …
Time at risk: Individual spatial behaviour drives effectiveness of marine protected areas and fitness
2021
11 pages, 6 figures, 1 table.-- Under a Creative Commons license
Inferring individual fate from aquatic acoustic telemetry data
2020
13 pages, 8 figures, 1 table.-- This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
Why do house-hunting ants recruit in both directions?
2007
8 pages; International audience; To perform tasks, organisms often use multiple procedures. Explaining the breadth of such behavioural repertoires is not always straightforward. During house hunting, colonies of Temnothorax albipennis ants use a range of behaviours to organise their emigrations. In particular, the ants use tandem running to recruit na? ants to potential nest sites. Initially, they use forward tandem runs (FTRs) in which one leader takes a single follower along the route from the old nest to the new one. Later, they use reverse tandem runs (RTRs) in the opposite direction. Tandem runs are used to teach active ants the route between the nests, so that they can be involved qui…
Evidence for ontogenetically and morphologically distinct alternative reproductive tactics in the invasive Round Goby Neogobius melanostomus.
2017
Alternative reproductive tactics are characterized by the occurrence of discrete alternative morphs that differ in behavioural, morphological and physiological traits within the same sex. Although much effort has been made to describe the behaviour, morphology and physiology of such alternative morphs, less effort has been invested investigating how much overlap there is in the characteristics of such morphs in natural populations. We studied random population samples of the invasive Round Goby Neogobius melanostomus from five different localities in the river Rhine system in the Netherlands. We found two morphologically and physiologically distinct male morphs which likely represent altern…
Within-season movements of Alpine songbird distributions are driven by fine-scale environmental characteristics
2020
AbstractInformation about distribution and habitat use of organisms is crucial for conservation. Bird distribution within the breeding season has been usually considered static, but this assumption has been questioned. Within-season movements may allow birds to track changes in habitat quality or to adjust site choice between subsequent breeding attempts. Such movements are especially likely in temperate mountains, given the substantial environmental heterogeneity and changes occurring during bird breeding season. We investigated the within-season movements of breeding songbirds in the European Alps in spring-summer 2018, using repeated point counts and dynamic occupancy models. For all the…
Testosterone-Mediated Effects on Fitness-Related Phenotypic Traits and Fitness
2009
International audience; The physiological and behavioral mechanisms underlying life-history trade-offs are a continued source of debate. Testosterone (T) is one physiological factor proposed to mediate the trade-off between reproduction and survival. We use phenotypic engineering and multiple laboratory and field fitness-related phenotypic traits to test the effects of elevated T between two bank vole Myodes glareolus groups: dominant and subordinate males. Males with naturally high T levels showed higher social status (laboratory dominance) and mobility (distance between capture sites) than low-T males, and the effect of T on immune response was also T group specific, suggesting that behav…
Unveiling the diet of the thermophilic starfish Ophidiaster ophidianus (Echinodermata: Asteroidea) combining visual observation and stable isotopes a…
2020
The starfish Ophidiaster ophidianus is an Atlanto-Mediterranean species protected under the EU’s Habitat Directive. Despite the wide distribution and the current range of expansion of this thermophilic species in the northern Mediterranean Sea, nothing is known about its diet. Using field observations and δ13C and δ15N Stable Isotopes Analysis (SIA), the feeding habits of O. ophidianus were explored in two Mediterranean rocky reef areas located in the southern Tyrrhenian (Ustica Island, Italy) and the eastern Adriatic Sea (Molunat, Croatia). According to field observations, O. ophidianus preys mainly on crustose coralline algae (CCA) and the keratose sponge Ircinia variabilis in both areas.…
Assessing geographical variation on whistle acoustic structure of three Mediterranean populations of common bottlenose dolphin (Tursiops truncatus)
2017
Whistles are acoustic signals produced particularly during social interactions. Here, we compare whistles by bottlenose dolphins from three Mediterranean areas (Croatia, Sicily and Sardinia) to investigate the presence of acoustic divergence and to discuss the possible causes of variability. Whistle parameters differ significantly between populations, but PCA highlights that the majority of variability is due to a limited number of frequency parameters. Cluster and DFA show that the Croatian population is acoustically divergent from the western populations of Sicily and Sardinia. This divergence could be consistent with geographical isolation, and a possible genetic differentiation between …
Seabird migration strategies: Flight budgets, diel activity patterns and lunar influence
2021
Every year, billions of birds undertake extensive migrations between breeding and nonbreeding areas, facing challenges that require behavioural adjustments, particularly to flight timing and duration. Such adjustments in daily activity patterns and the influence of extrinsic factors (e.g., environmental conditions, moonlight) have received much more research attention in terrestrial than marine migrants. Taking advantage of the widespread deployment in recent decades of combined light-level geolocator-immersion loggers, we investigated diel organisation and influence of the moon on flight activities during the non-breeding season of 21 migrant seabird species from a wide taxonomic range (6 …