Sélection d'habitat et dynamique spatio-temporelle des colonies chez deux espèces de laridés, la Mouette rieuse et le Goéland railleur
Author:
Francesiaz C. (contact)
Abstract:
Population dynamics addresses the processes that underpin the spatio-temporal fluctuations of organism counts. My PhD dissertation aims at characterizing the connections between three organization levels in colonial bird populations, the individual, the colony, and the meta-colony, and at investigating the influence of the physical and social environments on this organization. To this aim, I focused on two colonial larid species that exhibit contrasted population dynamics: the Black Headed Gull, Chroicocephalus ridibundus, and the Slender-Billed Gull, Chroicocephalus genei. I first described the population dynamics of French Slender-Billed Gull colonies, which are currently spreading along the Mediterranean coast. In spite of this expansion, individuals born in France return to their natal area to breed, but their age and sex modulate their recruitment and dispersal behaviours. I added-up to this first results by showing that nestling body condition, a major factor for recruitment, is affected by colony size, arrival date and parental foraging strategy. I further showed that Slender-Billed Gulls gather into social groups whose stability is modulated by colony breeding success. The strength of inter-individual relationships within a colony is thus modulated by its intrinsic properties and its environmental context. Furthermore, I showed that, in Black-Headed Gulls, colony persistance varies with local breeding success while colonization of new sites is mainly related to breeding success in eighbouring colonies. I conclude overall that the multiple organization levels of colonial bird populations, from the individual to the meta-colony, should be studied within integrative frameworks that represent novel conceptual, methodological and technical challenges at the crossroad between population dynamics and the study of social networks.
Full bibliographical reference:
Francesiaz, C. Sélection d’habitat et dynamique spatio-temporelle des colonies chez deux espèces de laridés : la Mouette rieuse et le Goéland railleur [Thèse]. Université de Montpellier, 2016. 406 p.