Search results for "proies"
showing 3 items of 3 documents
Coexistence of Mediterranean tits: A multidimensional approach
2013
[EN] Differential traits (e.g., feeding at different heights in trees) have evolved to allow the coexistence of putative competitors; such traits have been well studied in small passerines (e.g., Paridae), mainly during the winter. However, few studies have been carried out during the breeding season, when competition could be more intense. We applied here a multidimensional approach, examining ecological (prey type and size, and nesting habitat characteristics) and life history (timing of maximum nestling food demand) traits that might help to explain the coexistence of great (Parus major), crested (Lophophanes cristatus), and coal (Periparus ater) tits breeding in a Mediterranean pine for…
The role of biotic interactions in a prey-predator system : the case of predation and regulation of weed seeds by carabids.
2020
For the transition towards agricultural production systems that are less dependent on herbicides, the use of weed regulation by seed-eating carabids is of great interest. Weed seed predation by carabids is variable and occurs within a complex context of many biotic interactions. This complexity partly explains our current inability to predict levels of in-field weed regulation. In this thesis, I analysed variations in the levels of predation and biological regulation of weeds and determined how they respond to two classes of biotic interactions: 1) the availability of alternative prey; and, 2) intra- and inter-specific interactions between the carabids themselves. Field measurements carried…
Les coléoptères carabiques sont-ils plus sélectifs face à un risque de prédation ou de compétition ?
2017
Le temps nécessaire à l’évaluation et à l’acceptation d’une ressource est directement lié à sa qualité. Ainsi, les individus s’approvisionnant dans un milieu naturel font face à un compromis entre vitesse de prise de décision et qualité de la ressource (speed-accuracy trade-off). Si la qualité de la ressource est un élément important pour favoriser sa valeur adaptative (fitness), le temps nécessaire au processus de décision n’est plus disponible pour d’autres tâches essentielles comme la vigilance. De plus, une prise de décision trop longue expose aussi les individus à un risque plus important de compétition et de perte d’opportunités. On s’attend à ce que des animaux confrontés à un risque…