Search results for " animal"
showing 10 items of 3438 documents
Predictions of avian Plasmodium expansion under climate change.
2013
International audience; Vector-borne diseases are particularly responsive to changing environmental conditions. Diurnal temperature variation has been identified as a particularly important factor for the development of malaria parasites within vectors. Here, we conducted a survey across France, screening populations of the house sparrow (Passer domesticus) for malaria (Plasmodium relictum). We investigated whether variation in remotely-sensed environmental variables accounted for the spatial variation observed in prevalence and parasitemia. While prevalence was highly correlated to diurnal temperature range and other measures of temperature variation, environmental conditions could not pre…
Hydrogen isotopes reveal evidence of migration of Miniopterus schreibersii in Europe
2020
Abstract Background The Schreiber’s bat, Miniopterus schreibersii, is adapted to long-distance flight, yet long distance movements have only been recorded sporadically using capture-mark-recapture. In this study, we used the hydrogen isotopic composition of 208 wing and 335 fur specimens from across the species' European range to test the hypothesis that the species migrates over long distances. Results After obtaining the hydrogen isotopic composition (δ2H) of each sample, we performed geographic assignment tests by comparing the δ2H of samples with the δ2H of sampling sites. We found that 95 bats out of 325 showed evidence of long-distance movement, based on the analysis of either fur or …
Melanism is related to behavioural lateralization in nestling barn owls.
2017
5 pages; International audience; Behavioural laterality is a commonly observed phenomenon in many species suggesting there might be an advantage of using dominantly one side over the other for certain tasks. Indeed, lateralized individuals were often shown to be more successful in cognitive tasks compared to non-lateralized conspecifics. However, stressed individuals are also often, but not always, more strongly lateralized. Because barn owl (Tyto alba) females displaying larger black spots on the tip of their ventral feathers produce offspring that are more resistant to a variety of environmental stressful factors, we examined whether laterality is associated with melanin-based coloration.…
Quantitative Genetics of the Aging of Reproductive Traits in the Houbara Bustard
2015
International audience; Do all traits within an organism age for the same reason? Evolutionary theories of aging share a common assumption: the strength of natural selection declines with age. A corollary is that additive genetic variance should increase with age. However, not all senescent traits display such increases suggesting that other mechanisms may be at play. Using longitudinal data collected from more than 5400 houbara bustards (Chlamydotis undulata) with an exhaustive recorded pedigree, we investigated the genetics of aging in one female reproductive trait (egg production) and three male reproductive traits (courtship display rate, ejaculate size and sperm viability), that displa…
Predicting the effectiveness of oil recovery strategies in the marine polluted environment
2018
Abstract Many recent studies have focused their attention on the physiological stress experienced by marine organisms in measuring ecotoxicological responses. Here we suggest a new approach for investigating the effects of an anthropogenic pollutant on Life-History (LH) traits of marine organisms, to provide stakeholders and policy makers an effective tool to evaluate the best environmental recovery strategies and plans. A Dynamic Energy Budget (DEB), coupled with a biophysical model was used to predict the effects of a six-month oil spill on Mytilus galloprovincialis' LH traits and to test two potential recovery strategies in the central Mediterranean Sea. Oxygen consumption rates were use…
Behavioral response of brown meagre (Sciaena umbra) to boat noise
2016
Underwater man-made noise is recognized as a major global pollutant in the 21st Century, and its reduction has been included in national and international regulations. Despite the fact that many studies have pointed out the ecological impact of noise on marine organisms, few studies have investigated - in a field context - the behavioral response to boat noise in fish. In the present study we measure how Sciaena umbra reacts to boat noise. We found that boat noise: i) increased duration of flight reactions and number of individuals performing them, ii) increased the frequency of hiding behaviors, and iii) did not elicit a change in fish activity level and sound emission. Flights and hiding …
Response to: The metabolic cost of whistling is low but measurable in dolphins
2020
Costs of sound production have been investigated only sparsely in cetaceans, despite recent efforts to understand how increasing anthropogenic noise affects these animals that rely extensively on sound for communication and foraging. Theoretical estimates suggest that metabolic costs of whistling
Parasite communities in Boops boops (L.) (Sparidae) after the Prestige oil-spill: Detectable alterations
2007
Environmental pollution affects parasite populations and communities, both directly and through effects on intermediate and final hosts. In this work, we present a comparative study on the structure and composition of metazoan parasite communities in the bogue, Boops boops, from two localities (Galician coast, Spain) affected by the Prestige oil-spill (POS). We focus on the distribution of both individual parasite species and larger functional groupings by using both univariate and multivariate analyses. Our results indicate directional trends in community composition that might be related to the Prestige oil-spill disturbance of the natural coastal communities off Galicia. Endoparasite com…
Life-cycle switching and coexistence of species with no niche differentiation.
2011
The increasing evidence of coexistence of cryptic species with no recognized niche differentiation has called attention to mechanisms reducing competition that are not based on niche-differentiation. Only sex-based mechanisms have been shown to create the negative feedback needed for stable coexistence of competitors with completely overlapping niches. Here we show that density-dependent sexual and diapause investment can mediate coexistence of facultative sexual species having identical niches. We modelled the dynamics of two competing cyclical parthenogens with species-specific density-dependent sexual and diapause investment and either equal or different competitive abilities. We show th…
Molecular systematics in the acanthocephalan genus Echinorhynchus (sensu lato) in northern Europe
1994
SUMMARYNew biological species and high levels of inter- and intraspecific genetic divergence were discovered in an allozyme study of some North European members of the acanthocephalan genus Echinorhynchus (sensu lato), parasites of fish and malacostracan crustaceans. (i) A strong differentiation between the marine E. gadi and the fresh- and brackish-water E. salmonis (genetic identity I ≃ 0) supports a generic distinction between these taxa; however, the subdivision would not entirely concur with the concepts of Echinorhynchus (sensu stricto) and Metechinorhynchus suggested earlier. (ii) Samples of E. gadi from the Baltic, Norwegian and North Seas included three distinct, partially sympatri…