Expérimentarium - Dans le cadre du parcours Avenir, rencontre avec une classe de 3ème

International audience

More choosy under a risk of predation or of competition

International audience; Animals foraging in the wild face a trade-off between staying safe (i.e. avoiding predation orstarvation) and the quality of the food. We therefore hypothesize that animals will modify their foodselection (choosiness) both under competition and predation risk, but that the direction and theamount of change in choosiness will depend on the level of risk they face.To test this hypothesis, the foraging behaviour of the carabid beetle, Harpalus affinis, was examinedunder 4 different experimental conditions: predation risk, intra- and interspecific competition and acontrol.Our results show that when foraging under the risk of predation or competition animals reduce theirc…

Expérimentarium - Alice au pays des carabes

Rien de tel que les gestes du dessinateur pour faire vivre les gestes du chercheur. Thibault Roy, Marie-Laure Baudement et Jo-Ann Campion ont rencontré des doctorants de toutes disciplines afin d’échanger sur leurs pratiques. Ces dessins illustrent ces rencontres et ces échanges. La Mission Culture Scientifique protège et valorise les collections scientifiques et techniques. Ces collections participent à la recherche et à sa valorisation. Ce sont des ressources irremplaçables pour la science et l’avancement des connaissances dans de nombreux domaines tels que le changement climatique, l’écologie et l’évolution des systèmes vivants, la géologie, l’archéologie, l’ethnologie, l’anthropologie, …

Après-midi Grand Public de l'Expérimentarium en Bourgogne

National audience; Rencontre avec le public pour discuter avec le public du quotidien des scientifiques et faire découvrir leurs recherches, Centre des Sciences du Goût et de l'Alimentation, Dijon, 3 avril 2016.

Can obligatory omnivore carabids be useful for the biocontrol of weeds?

National audience; Many thousands of carabid individuals exist in farm fields, in communities of carnivore and opportunistic (e.g. granivores) and obligate omnivore guilds. As carabids can eat a substantial amount of weed seeds they are considered as credible biocontrol agents for the regulation of weeds in arable fields. Some studies have suggested that “granivores” are more important biocontrol agents than obligate omnivorous species. Yet, in some instances, obligate omnivores are very abundant and appear to drive the predation of weeds leading some authors to question whether specialist natural enemies are better. Moreover, niche complementarity, facilitation and interference (i.e. intra…

Un prédateur généraliste peut-il être un bon candidat pour le biocontrôle des adventices

International audience

Effets de la variabilité inter-individuelles et des interactions intra-guildes sur les stratégies d'approvisionnement de carabes consommateurs de graines

Making a choice requires, implicitly, an investment of time in one behaviour at the expense of an investment in another. Being choosy would increase the risk of losing many food item opportunities to competitors, and is directly in conflict with other essential tasks such as predator avoidance. Individuals are thus expected to adjust their level of choosiness in response to the competition and predation context. The available behavioural ecological theory and the empirical ecology of carabids would suggest that competition and predation interference induces changes in the foraging behaviour of carabid individuals. Carabids typically operate within communities in which competition and predat…

Risk of predation makes foragers less choosy about their food.

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…

Expérimentarium - de jeunes chercheurs de l'INRA de Dijon à la rencontre du grand public - Médiathèque du Port du Canal Dijon

National audience; Les jeunes chercheurs à la rencontre du publicDemain mercredi 8 mars de 15h à 17h30 à la bibliothèque municipale Mansart, 3 jeunes chercheurs dijonnais partageront leur goût de la science avec le grand public.Parmi eux, Pauline Brugaillères, chercheuse en science de l’alimentation au CSGA, et Alice Charalabidis, chercheuse en comportement animal au sein de l’UMR Agroécologie.Pauline s’intéresse au comportement alimentaire des bébés et se demande s’ils sont capables d’ajuster les quantités qu’ils mangent. Alice, elle, se penche sur les carabes, ces petites bêtes mangent les graines des mauvaises herbes présentes dans les champs.Venez leur poser vos questions dans le cadre …

Les coléoptères carabiques sont-ils plus sélectifs face à un risque de prédation ou de compétition ?

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…

Diversity of foraging strategies and responses to predator interference in seed-eating carabid beetles

12 pages; International audience; The prediction of pest regulation by multi-predator communities often remains challenging because of variable and opposite effects of niche complementarity and predator interference. Carabid communities are regulating weeds in arable fields and include a mix of species ranging from granivores to predators that are obligate omnivores. It is not clear from field studies whether granivore and obligate omnivore species either contribute equally or are complementary in the process of weed suppression, and little is known about the impact of potential predator interference within carabid communities on weed suppression. We compared the weed seed foraging strategy…

Intervention sur les Carabidae

Stability of consumption pattern in two seed eating carabid species

SPEGESTADDOCT INRA; Carabids can eat a substantial amount of seeds of weeds per day and are considered as credible biocontrol agents for the regulation of weeds in arable fields. Carabids species belong to either granivore, omnivore or carnivore trophic guilds and we expected each of these to have specific patterns of weed seed consumption and specific responses to biotic interactions. These differences will impact the total predation rate of a carabid community and may also explain why it is difficult to predict the efficiency of carabid biocontrol service. To test this expectation, we looked at the consumption pattern of two species of carabids species common in arable fields, one known a…

Présentation des coléoptères carabiques en lien avec le service écosystémique de lutte contre les adventices

National audience

Effect of inter-individual variability and intraguild interferences on the foraging strategies of seed-eating carabid species

Making a choice requires, implicitly, an investment of time in one behaviour at the expense of an investment in another. Being choosy would increase the risk of losing many food item opportunities to competitors, and is directly in conflict with other essential tasks such as predator avoidance. Individuals are thus expected to adjust their level of choosiness in response to the competition and predation context. The available behavioural ecological theory and the empirical ecology of carabids would suggest that competition and predation interference induces changes in the foraging behaviour of carabid individuals. Carabids typically operate within communities in which competition and predat…