par Miranda, María 
Promoteur Warren, Ben
Co-Promoteur Morlon, Hélène
Publication Non publié, 2024-08-29
Promoteur Warren, Ben
Co-Promoteur Morlon, Hélène
Publication Non publié, 2024-08-29
Mémoire
| Résumé : | This study aims to enhance our understanding of insular communities by examining howtheir ecological niches change over time. We investigate whether island isolation affectsthe achievement and rate of niche saturation. Additionally, we explore whether theisland’s area and age influence the importance of colonization and speciation as driversof niche dynamics. To address these aims, we used phylogenetic data on insular birdsfrom 24 globally distributed archipelagos, along with morphological measurements of birdbeaks, to perform ancestral trait reconstruction and track community assembly acrossthese archipelagos. We utilized the range of traits to represent trait space, a proxy forniche space. By combining the traits of the entire community, we calculated its overall traitspace. Furthermore, we differentiated between colonizer and endemic (in situ speciated)species to assess the trait space of these subgroups separately, thereby gaining insightsinto the roles of colonization and speciation in niche dynamics. Our findings aresummarized in three main conclusions 1) Island isolation is not strongly related to thedynamics of niche space. 2) Large and old islands seem to achieve niche saturation. 3)Colonization is the principal mechanism driving niche dynamics on small and youngislands, whereas speciation is the main mechanism on larger and older islands. |
