Search results for "EB"
showing 10 items of 15658 documents
Risk of predation makes foragers less choosy about their food.
2017
18 pages; International audience; Animals foraging in the wild have to balance speed of decision making and accuracy of assessment of a food item's quality. If resource quality is important for maximizing fitness, then the duration of decision making may be in conflict with other crucial and time consuming tasks, such as anti-predator behaviours or competition monitoring. Individuals facing the risk of predation and/or competition should adjust the duration of decision making and, as a consequence, their level of choosiness for resources. When exposed to predation, the forager could either maintain its level of choosiness for food items but accept a reduction in the amount of food items con…
New records of phytoseiid mites from Italy, with description of a new species and a redescription of other two (Parasitiformes, Phytoseiidae)
2020
The Italian phytoseiid fauna consists of 91 valid species. Eighteen of them were described as new species from materials collected in various Italian localities. In the present paper we report nine new records from the Italian fauna and describe the new species, Neoseiulus mediterraneus belonging to the subfamily Amblyseiinae. Complementary descriptions of two rare species, namely: Typhlodromus (Anthoseius) singularis and Typhlodromus (Typhlodromus) knisleyi, were also added.
Pilosella hoppeana subsp. sicula Di Grist., Gottschl. & Raimondo (Asteraceae), a new endemic subspecies from Sicily (Italy)
2016
Abstract Di Gristina, E., G. Gottschlich & F.M. Raimondo (2016). Pilosella hoppeana subsp. sicula Di Grist., Gottschl. & Raimondo (Asteraceae), a new endemic subspecies from Sicily (Italy). Candollea 71: 7–12. In English, English abstract. DOI : http://dx.doi.org/10.15553/c2016v711a2 Pilosella hoppeana subsp. sicula Di Grist., Gottschl. & Raimondo (Asteraceae), a new endemic subspecies from the Madonie and Nebrodi Mountains (Sicily, Italy), is described and illustrated. It is morphologically close to Pilosella hoppeana subsp. macrantha (Ten.) S. Braut. & Greuter, but the two subspecies can be distinguished by the indument on the bracts. Its morphology, distribution, ecology, taxonomic relat…
Bees increase oilseed rape yield under real field conditions
2018
prod 2018-210 EA GESTAD INRA; International audience; Oilseed rape (OSR, Brassica napus L.) is a common crop found in many European agricultural landscapes. It ispollinated by a wide variety of insects, but the reported contribution of pollinators to yield varies widely betweenstudies (from 0 to 50%). Moreover, such a contribution has seldom been estimated at the field scale in realfarming conditions. We analysed OSR yields in response to insect pollination; over four years, at two differentscales: farm fields and individual plants. We used both empirical and experimental approaches along a gradientof pollinator diversity and abundance. The empirical approach was based on farm surveys (151 …
Resource profitability, but not caffeine, affects individual and collective foraging in the stingless beePlebeia droryana
2019
ABSTRACT Plants and pollinators form beneficial relationships, with plants offering resources in return for pollination services. Some plants, however, add compounds to nectar to manipulate pollinators. Caffeine is a secondary plant metabolite found in some nectars that affects foraging in pollinators. In honeybees, caffeine increases foraging and recruitment to mediocre food sources, which might benefit the plant, but potentially harms the colonies. For the largest group of social bees, the stingless bees, the effect of caffeine on foraging behaviour has not been tested yet, despite their importance for tropical ecosystems. More generally, recruitment and foraging dynamics are not well und…
Proposed Environmental Risk Management Elements in a Carpathian Valley Basin, within the Roşia Montană European Historical Mining Area
2021
Non-ferrous metals mining activities have long accompanied people, and began in the study area of South East Europe over 2000 years ago. The environment quality is significantly affected by both historic mining activities and contemporary impacts. All these problems, inducing synergic negative effects on local organism communities, have created a chronic state of pollution. The Corna Valley has one of the oldest historical human impacts in Romania due to the influence of mining. Fish and benthic macroinvertebrates have exhibited significant responses to long term mining effects on lotic systems. The analysis of macroinvertebrate communities, correlated with the lack of fish and some biotope…
Amount, composition, and spatial distribution of floating macro litter along fixed trans-border transects in the Mediterranean basin
2018
Marine litter is a major source of pollution in the Mediterranean basin, but despite legislative requirements, scant information is available for the ongoing assessment of this threat. Using higher size classes as proxy for litter distribution, this study gave a synoptic estimation of the amount, composition, and distribution of floating macro-litter in the Mediterranean. The average amount of macro-litter was in a range of 2-5 items/km2, with the highest in the Adriatic basin. Seasonal patterns were present in almost all study areas and were significant in the Ligurian Sea, Sardinian-Balearic basin, and Central Tyrrhenian Sea. Plastic accounted for > 80% of litter in all areas and seaso…
An Empirical Evaluation of the Utility of Convex Hull and Standard Ellipse Areas for Assessing Population Niche Widths from Stable Isotope Data
2013
Stable isotope analyses are increasingly employed to characterise population niche widths. The convex hull area (TA) in a δ¹³C–δ¹⁵N biplot has been used as a measure of isotopic niche width, but concerns exist over its dependence on sample size and associated difficulties in among-population comparisons. Recently a more robust method was proposed for estimating and comparing isotopic niche widths using standard ellipse areas (SEA), but this approach has yet to be tested with empirical stable isotope data. The two methods measure different kind of isotopic niche areas, but both are now widely used to characterise isotopic niche widths of populations. We used simulated data and an extensive e…
A recipe for postfledging survival in great tits Parus major: be large and be early (but not too much)
2016
Survival of juveniles during the postfledging period can be markedly low, which may have major consequences on avian population dynamics. Knowing which factors operating during the nesting phase affect postfledging survival is crucial to understand avian breeding strategies. We aimed to obtain a robust set of predictors of postfledging local survival using the great tit (Parus major) as a model species. We used mark–recapture models to analyze the effect of hatching date, temperatures experienced during the nestling period, fledging size and body mass on first-year postfledging survival probability of great tit juveniles. We used data from 5192 nestlings of first clutches ringed between 199…
The role of fish life histories in allometrically scaled food‐web dynamics
2019
Body size determines key ecological and evolutionary processes of organisms. Therefore, organisms undergo extensive shifts in resources, competitors, and predators as they grow in body size. While empirical and theoretical evidence show that these size‐dependent ontogenetic shifts vastly influence the structure and dynamics of populations, theory on how those ontogenetic shifts affect the structure and dynamics of ecological networks is still virtually absent. Here, we expand the Allometric Trophic Network (ATN) theory in the context of aquatic food webs to incorporate size‐structure in the population dynamics of fish species. We do this by modifying a food web generating algorithm, the nic…