Browsing by Autor "Carine Emer"

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Birds optimize fruit size consumed near their geographic range limits
(American Association for the Advancement of Science, 2024) Lucas Pereira Martins; Daniel B. Stouffer; Pedro G. Blendinger; Katrin Böhning‐Gaese; José Miguel Costa; D. Matthias Dehling; Camila I. Donatti; Carine Emer; Mauro Galetti; Rúben Heleno
Animals can adjust their diet to maximize energy or nutritional intake. For example, birds often target fruits that match their beak size because those fruits can be consumed more efficiently. We hypothesized that pressure to optimize diet-measured as matching between fruit and beak size-increases under stressful environments, such as those that determine species' range edges. Using fruit-consumption and trait information for 97 frugivorous bird and 831 plant species across six continents, we demonstrate that birds feed more frequently on closely size-matched fruits near their geographic range limits. This pattern was particularly strong for highly frugivorous birds, whereas opportunistic frugivores showed no such tendency. These findings highlight how frugivore interactions might respond to stressful conditions and reveal that trait matching may not predict resource use consistently.
Global and regional ecological boundaries drive abrupt changes in avian frugivory interactions
(2021) Lucas Pereira Martins; Daniel B. Stouffer; Pedro G. Blendinger; Katrin Böhning‐Gaese; Galo Buitrón‐Jurado; Marta Correia; José Miguel Costa; D. Matthias Dehling; Camila I. Donatti; Carine Emer
Abstract Species interactions can propagate disturbances across space, though ecological and biogeographic boundaries may limit this spread. We tested whether large-scale ecological boundaries (ecoregions and biomes) and human disturbance gradients increase dissimilarity among ecological networks, while accounting for background spatial and elevational effects and differences in network sampling. We assessed network dissimilarity patterns over a broad spatial scale, using 196 quantitative avian frugivory networks (encompassing 1,496 plant and 1,003 bird species) distributed across 67 ecoregions and 11 biomes. Dissimilarity in species and interactions, but not in network structure, increased significantly across ecoregion and biome boundaries and along human disturbance gradients. Our findings suggest that ecological boundaries contribute to maintaining the world’s biodiversity of interactions and mitigating the propagation of disturbances at large spatial scales. One-Sentence Summary Ecoregions and biomes delineate the large-scale distribution of plant-frugivore interactions.
Global and regional ecological boundaries explain abrupt spatial discontinuities in avian frugivory interactions
(Nature Portfolio, 2022) Lucas Pereira Martins; Daniel B. Stouffer; Pedro G. Blendinger; Katrin Böhning‐Gaese; Galo Buitrón‐Jurado; Marta Correia; José Miguel Costa; D. Matthias Dehling; Camila I. Donatti; Carine Emer
Seed‐dispersal networks are more specialized in the Neotropics than in the Afrotropics
(Wiley, 2018) Phillip J. Dugger; Pedro G. Blendinger; Katrin Böhning‐Gaese; Lackson Chama; Marta Correia; D. Matthias Dehling; Carine Emer; Nina Farwig; Evan C. Fricke; Mauro Galetti
Abstract Aim Biogeographical comparisons of interaction networks help to elucidate differences in ecological communities and ecosystem functioning at large scales. Neotropical ecosystems have higher diversity and a different composition of frugivores and fleshy‐fruited plants compared with Afrotropical systems, but a lack of intercontinental comparisons limits understanding of (a) whether plant–frugivore networks are structured in a similar manner, and (b) whether the same species traits define the roles of animals across continents. Location Afrotropics and Neotropics. Time period 1977–2015. Taxa Fleshy‐fruited plants and frugivorous vertebrates. Methods We compiled a dataset comprising 17 Afrotropical and 48 Neotropical weighted seed‐dispersal networks quantifying frugivory interactions between 1,091 fleshy‐fruited plant and 665 animal species, comprising in total 8,251 interaction links between plants and animals. In addition, we compiled information on the body mass of animals and their degree of frugivory. We compared four standard network‐level metrics related to interaction diversity and specialization, accounting for differences related to sampling effort and network location. Furthermore, we tested whether animal traits (body mass, degree of frugivory) differed between continents, whether these traits were related to the network roles of species and whether these relationships varied between continents. Results We found significant structural differences in networks between continents. Overall, Neotropical networks were less nested and more specialized than Afrotropical networks. At the species level, a higher body mass and degree of frugivory were associated with an increasing diversity of plant partners. Specialization of frugivores increased with the degree of frugivory, but only in the Neotropics. Main conclusions Our findings show that Afrotropical networks have a greater overlap in plant partners among vertebrate frugivores than the more diverse networks in the Neotropics that are characterized by a greater niche partitioning. Hence, the loss of frugivore species could have stronger impacts on ecosystem functioning in the more specialized Neotropical communities compared with the more generalized Afrotropical communities.