Search results for "dati"
showing 10 items of 8549 documents
Effects of food abundance and early clutch predation on reproductive timing in a high Arctic shorebird exposed to advancements in arthropod abundance.
2016
12 pages; International audience; Climate change may influence the phenology of organisms unequally across trophic levels and thus lead to phenological mismatches between predators and prey. In cases where prey availability peaks before reproducing predators reach maximal prey demand, any negative fitness consequences would selectively favor resynchronization by earlier starts of the reproductive activities of the predators. At a study site in northeast Greenland, over a period of 17 years, the median emergence of the invertebrate prey of Sanderling Calidris alba advanced with 1.27 days per year. Yet, over the same period Sanderling did not advance hatching date. Thus, Sanderlings increasin…
Obtention and characterization of resistant starch from creole faba bean (Vicia faba L. creole) as a promising functional ingredient
2021
Abstract A procedure easy to upscale industrially aimed at obtaining resistant starch (RS) type III (RS-III) was optimized, using a native faba bean from Mexico (Vicia faba L. creole) as RS source for the first time. Pullulanase debranching treatment (6–18 enzyme units (U)/g starch; 0–27 h) and retrogradation process (−30 °C, 2 °C or 20 °C; 1–6 days) was optimized for faba beans. Optimal conditions were determined at 18 U/g for 27 h and a retrogradation process at 20 °C for 6 days. Obtained faba bean RS was also compared with RS obtained from conventional sources, beans (Phaseolus vulgaris L. Jamapa) and maize, under these optimal conditions. Beans (faba beans, 64.88%; beans, 64.84%) yielde…
Discriminating uniparental and biparental breeding strategies by monitoring nest temperature
2017
10 pages; International audience; Birds exhibit a wide diversity of breeding strategies. During incubation or chick-rearing, parental care can be either uniparental, by either the male or the female, or biparental. Understanding the selective pressures that drive these different strategies represents an exciting challenge for ecologists. In this context, assigning the type of parental care at the nest (e.g. biparental or uniparental incubation strategy) is often a prerequisite to answering questions in evolutionary ecology. The aim of this study was to produce a standardized method unequivocally to assign an incubation strategy to any Sanderling Calidris alba nest found in the field by moni…
Occupation of wood warbler Phylloscopus sibilatrix nests by Myrmica and Lasius ants
2018
Bird nests can provide habitats for various invertebrates, including ectoparasites, scavengers, and predators. Records of ants associating with active bird nests mostly involve the insects searching for food, with some exceptional records of ants raising their broods (eggs, larvae or pupae) within songbird nests in nest-boxes or tree cavities. We present data for a previously undocumented, but apparently regular, occurrence of ants and their broods within the active nests of a songbird, the wood warbler Phylloscopus sibilatrix (Bechstein, 1793), which builds domed nests on the ground in European forests. Systematic recording found ants, mostly Myrmica ruginodis Nylander, 1846, in 43% of 80 …
Camouflage accuracy in Sahara–Sahel desert rodents
2020
1. Camouflage helps animals to hide from predators and is therefore key to survival. Although widespread convergence of animal phenotypes to their natural environment is well-established, there is a lack of knowledge about how species compromise camouflage accuracy across different background types in their habitat.2. Here we tested how background matching has responded to top–down selection by avian and mammalian predators using Sahara–Sahel desert rodents in North Africa.3. We show that the fur colouration of several species has become an accurate match to different types of desert habitats. This is supported by a correlation analysis of colour and pattern metrics, investigation of animal…
Ecosystem carbon response of an Arctic peatland to simulated permafrost thaw
2019
Permafrost peatlands are biogeochemical hot spots in the Arctic as they store vast amounts of carbon. Permafrost thaw could release part of these long-term immobile carbon stocks as the greenhouse gases (GHGs) carbon dioxide (CO 2 ) and methane (CH 4 ) to the atmosphere, but how much, at which time-span and as which gaseous carbon species is still highly uncertain. Here we assess the effect of permafrost thaw on GHG dynamics under different moisture and vegetation scenarios in a permafrost peatland. A novel experimental approach using intact plant–soil systems (mesocosms) allowed us to simulate permafrost thaw under near-natural conditions. We monitored GHG flux dynamics via high-resolution…
Fishery-dependent and -independent data lead to consistent estimations of essential habitats
2016
AbstractSpecies mapping is an essential tool for conservation programmes as it provides clear pictures of the distribution of marine resources. However, in fishery ecology, the amount of objective scientific information is limited and data may not always be directly comparable. Information about the distribution of marine species can be derived from two main sources: fishery-independent data (scientific surveys at sea) and fishery-dependent data (collection and sampling by observers in commercial vessels). The aim of this paper is to compare whether these two different sources produce similar, complementary, or different results. We compare them in the specific context of identifying the Es…
Modelling sensitive elasmobranchs habitat
2013
Basic information on the distribution and habitat preferences of ecologically important species is essential for their management and protection. In the Mediterranean Sea there is increasing concern over elasmobranch species because their biological (ecological) characteristics make them highly vulnerable to fishing pressure. Their removal could affect the structure and function of marine ecosystems, inducing changes in trophic interactions at the community level due to the selective elimination of predators or prey species, competitors and species replacement. In this study Bayesian hierarchical spatial models are used to map the sensitive habitats of the three most caught elasmobranch spe…
Parasite transmission in aquatic ecosystems under temperature change: effects of host activity and elimination of parasite larvae by filter‐feeders
2020
A moderate raise in temperature was suggested to enhance the impact of parasites on aquatic ecosystems. Under higher temperatures, poikilothermic animals (e.g. fish) increase their activity, which can result in a more frequent encounter with parasites. However, temperature increase may also trigger processes counteracting an increased risk of parasitic infections. Thus, the removal of free‐living stages of parasites by filter‐feeding organisms can increase with temperature and potentially mitigate disease risk in ecosystems under climate change. We aimed to study whether an increased infection transmission under higher temperatures can be compensated by the increased removal of parasitic la…
Characteristics, Main Impacts, and Stewardship of Natural and Artificial Freshwater Environments: Consequences for Biodiversity Conservation
2020
International audience; In this overview (introductory article to a special issue including 14 papers), we consider all main types of natural and artificial inland freshwater habitas (fwh). For each type, we identify the main biodiversity patterns and ecological features, human impacts on the system and environmental issues, and discuss ways to use this information to improve stewardship. Examples of selected key biodiversity/ecological features (habitat type): narrow endemics, sensitive (groundwater and GDEs); crenobionts, LIHRes (springs); unidirectional flow, nutrient spiraling (streams); naturally turbid, floodplains, large-bodied species (large rivers); depth-variation in benthic commu…