Search results for "EDA"

2019

Predation risk and food: opposite effects on overwintering survival and onset of breeding in a boreal rodent

2012

1. In seasonal environments, optimal onset of breeding and survival plays major roles in individual fitness. Many physiological and behavioural factors related to breeding increase the risk of predation; thus, breeding decisions should be based on current risks and benefits. According to life-history theory, if current predation risk is high and breeding itself increases the risk, it may be beneficial to postpone breeding. 2. During winter in northern hemispheres, food availability is limited and is at its lowest just prior to the onset of breeding in spring. Food constraint may lead to poor condition and reduced ability to start breeding. 3. We studied the effects of food and predation ris…

The roles of temperature, nest predators and information parasites for geographical variation in egg covering behaviour of tits (Paridae)

2020

Abstract Aim: Nest building is widespread among animals. Nests may provide receptacles for eggs, developing offspring and the parents, and protect them from adverse environmental conditions. Nests may also indicate the quality of the territory and its owner and can be considered as an extended phenotype of its builder(s). Nests may, thus, function as a sexual and social signal. Here, we examined ecological and abiotic factors—temperature, nest predation and interspecific information utilization—shaping geographical variation in a specific nest structure—hair and feather cover of eggs—and its function as an extended phenotype before incubation in great (Parus major) and blue tits (Cyanistes …

Factors affecting population dynamics of Eurasian woodcocks wintering in France: assessing the efficiency of a hunting-free reserve

2005

International audience; The Eurasian woodcock Scolopax rusticola is a migratory bird of major importance for hunting, which is susceptible to habitat loss and the stochastic effects of severe winter weather. Conservation issues mostly concerned regulation of hunting, but the efficiency of hunting-free reserves has never been investigated. We studied causes of mortality and survival probabilities of 98 radio-tagged woodcocks in a reserve with no hunting and in an adjoining hunting area in Brittany (France). Predation, mostly by mammalian predators on fields at night, was similar among adults and yearlings, while hunting mortality was more important in yearlings. Overall winter survival proba…

Lake eutrophication and brownification downgrade availability and transfer of essential fatty acids for human consumption

2016

Article

Gray plumage color is more cryptic than brown in snowy landscapes in a resident color polymorphic bird

2020

Abstract Camouflage may promote fitness of given phenotypes in different environments. The tawny owl (Strix aluco) is a color polymorphic species with a gray and brown morph resident in the Western Palearctic. A strong selection pressure against the brown morph during snowy and cold winters has been documented earlier, but the selection mechanisms remain unresolved. Here, we hypothesize that selection favors the gray morph because it is better camouflaged against predators and mobbers in snowy conditions compared to the brown one. We conducted an online citizen science experiment where volunteers were asked to locate a gray or a brown tawny owl specimen from pictures taken in snowy and snow…

Checklist of gypsophilous vascular flora in Italy

2018

Our understanding of the richness and uniqueness of the flora growing on gypsum substrates in Italy has grown significantly since the 19th century and, even today, new plant species are still being discovered. However, the plants and plant communities, growing on gypsum substrates in Italy, are still a relatively unknown subject. The main aim of this paper was to elaborate a checklist of the Italian gypsophilous flora, to increase knowledge about this peculiar flora and for which conservation efforts need to be addressed. Through a structured group communication process of experts (application of the Delphi technique), a remarkable number of experienced Italian botanists have joined togethe…

Time after time: flowering phenology and biotic interactions.

2007

International audience; The role of biotic interactions in shaping plant flowering phenology has long been controversial; plastic responses to the abiotic environment, limited precision of biological clocks and inconsistency of selection pressures have generally been emphasized to explain phenological variation. However, part of this variation is heritable and selection analyses show that biotic interactions can modulate selection on flowering phenology. Our review of the literature indicates that pollinators tend to favour peak or earlier flowering, whereas pre-dispersal seed predators tend to favour off-peak or later flowering. However, effects strongly vary among study systems. To unders…

Voles and weasels in the boreal Fennoscandian small mammal community : What happens if the least weasel disappears due to climate change?

2019

Climate change, habitat loss and fragmentation are major threats for populations and a challenge for individual behavior, interactions and survival. Predator–prey interactions are modified by climate processes. In the northern latitudes, strong seasonality is changing and the main predicted feature is shortening and instability of winter. Vole populations in the boreal Fennoscandia exhibit multiannual cycles. High amplitude peak numbers of voles and dramatic population lows alternate in 3–5‐year cycles shortening from North to South. One key factor, or driver, promoting the population crash and causing extreme extended lows, is suggested to be predation by the least weasel. We review the ar…

Demographic responses of a site-faithful and territorial predator to its fluctuating prey: long-tailed skuas and arctic lemmings.

2014

Summary1. Environmental variability, through interannual variation in food availability or climaticvariables, is usually detrimental to population growth. It can even select for constancy in keylife-history traits, though some exceptions are known. Changes in the level of environmentalvariability are therefore important to predict population growth or life-history evolution.Recently, several cyclic vole and lemming populations have shown large dynamical changesthat might affect the demography or life-histories of rodent predators.2. Skuas constitute an important case study among rodent predators, because of theirstrongly saturating breeding productivity (they lay only two eggs) and high deg…