Vol.:(0123456789) 1 3 Oecologia https://doi.org/10.1007/s00442-020-04662-4 PLANT-MICROBE-ANIMAL INTERACTIONS – ORIGINAL RESEARCH Drivers of bat roles in Neotropical seed dispersal networks: abundance is more important than functional traits Rafael de Souza Laurindo 1  · Jeferson Vizentin‑Bugoni 2  · Davi Castro Tavares 3  · Matheus Camargo Silva Mancini 1  · Rodrigo de Macêdo Mello 1  · Renato Gregorin 1 Received: 3 September 2019 / Accepted: 27 April 2020 © Springer-Verlag GmbH Germany, part of Springer Nature 2020 Abstract While functional traits can facilitate or constrain interactions between pair of species in ecological communities, relative abundances regulate the probabilities of encounter among individuals. However, the relative importance of traits and relative abundances for the role species play in seed dispersion networks remains poorly explored. Here, we analyzed 20 Neotropical seed dispersal networks distributed from Mexico to southeastern Brazil to evaluate how relative abundance and functional traits infuence bat species’ roles in seed dispersal networks. We tested how bat relative abundance and traits relate to spe- cies contribution to between-module (c metric) and within-module connectivity (z metric) and their position and potential to mediate indirect efects between species (betweenness centrality). Our results indicate that relative abundance is the main determinant of the role bats play in the networks, while traits such as aspect ratio show modest yet statistically signifcant importance in predicting specifc roles. Moreover, all seed dispersal networks presented two or three superabundant obliga- tory frugivore species that interacted with a high number of plants. The modest infuence of the functional traits on species’ roles is likely related to the low variation of morphological traits related to foraging ecology, which reduces the chances of morphological mismatching between consumers and resources in the system. In this scenario, abundant bats have higher chances of encountering resources and being capable of consuming them which leads such species to play critical roles in the community by acting as module hubs and network connectors. Keywords Chiroptera · Frugivory · Neotropics · Morphological traits · Mutualistic interactions Introduction In ecological communities, species interact one with another forming complex interaction networks (Bas- compte and Jordano 2007). Multiple processes defne net- works structure, and the role species play in communities (e.g. Vázquez et al. 2009; Vizentin-Bugoni et al. 2014; Sebastián-González 2017). In plant–frugivore mutualistic networks, usually a low number of animal species concen- trate a large proportion of the interactions and, therefore, play a pivotal role in the community. Thus, highly con- nected species disproportionally contribute for the net- work structure, while most of the species are often poorly connected and tend to play peripheral roles (Mello et al. 2015; Palacio et al. 2016; Laurindo et al. 2019). Distinct factors are associated to such roles, including popula- tion abundance and functional traits—here defned as any measurable morphological, physiological, and behavioral characteristics of an organism (Sebastián-González 2017; Communicated by David M. Watson. Electronic supplementary material The online version of this article (https://doi.org/10.1007/s00442-020-04662-4) contains supplementary material, which is available to authorized users. * Rafael de Souza Laurindo rafaelslaurindo@gmail.com 1 Departamento de Biologia, Universidade Federal de Lavras, CP 3037, Lavras, Minas Gerais CEP 37200-000, Brazil 2 Department of Natural Resources and Environmental Sciences, University of Illinois at Urbana-Champaign, Turner Hall, 1102 S Goodwin Avenue, Urbana, IL, USA 3 Systems Ecology Group, Leibniz Centre for Tropical Marine Research, Fahrenheitstraße 6, 28359 Bremen, Germany