DOI: 10.5061/dryad.573n5tb8p
title: The ability to disperse large seeds, rather than body mass alone, defines the importance of animals in a hyper-diverse seed dispersal network

description: 1. Large-bodied animals play irreplaceable roles in seed dispersal, partly
 due to their capacity to disperse large seeds. Understanding this role at
 a community level has been limited by the paucity of network studies that
 include large vertebrates, and the almost complete absence of studies
 including synzoochoric dispersers. Synzoochoric dispersers can disperse
 seeds disproportionately large for their body size, potentially
 overlapping the roles of large-bodied animals. A comprehensive network,
 inclusive of large vertebrates and synzoochorous dispersers, is imperative
 to understand seed dispersal at a community level. 2. Here, we analysed
 the seed dispersal network of a hyper-diverse Sundaic forest in Malaysia
 using local ecological knowledge and including multiple forms of
 endozoochorous and synzoochorous dispersal. We evaluated the extent to
 which three disperser traits: body mass, seed-handling ability (size of
 the largest seed dispersed), and diet explained the importance of animals
 in the network. We evaluated dispersers’ relative importance using four
 network metrics — degree of specialisation (nested rank), species
 strength, within-module connectivity (z-value), and between-modules
 connectivity (c-value). 3. We found that seed-handling ability had the
 biggest effect on a disperser’s importance, with strong effects on three
 network metrics (species strength, ecological specialization, z-value) and
 moderate effects on connectivity between modules. Body mass was important
 in defining interactions within modules, and dietary differences defined
 the ecological specialisation of species in seed dispersal. 4. Important
 dispersers in our network were large-seed dispersers (e.g., rats,
 gibbons), large-bodied animals, in particular the Asian elephant, and
 animals with frugivorous diets such as hornbills. 5. Synthesis. Our work
 uncovers the significance of seed-handling ability in identifying pivotal
 seed dispersal roles in tropical rainforests. Key dispersers include
 large-bodied herbivores and medium-sized frugivores that could disperse
 large seeds by endozoochory, and smaller rodents that dispersed
 similar-sized seeds by synzoochory. Many of the species that emerged as
 particularly important for the seed dispersal network are currently
 threatened (e.g., the Asian elephant, gibbons, and hornbills). Their
 protection or reintroduction should be a top conservation
 priority. 
description: The method is fully described in Ong et al. (2021),
 "Building ecological networks with local ecological knowledge in
 hyper-diverse and logistically challenging ecosystems", and Ong et
 al. (2021), " The ability to disperse large seeds, rather than body
 mass alone, defines the importance of animals in a hyper-diverse seed
 dispersal network".
description: The indices used for running the GLM models can be found in the
 following documents: Ong et al.
 2021_Aug2016toNov2017_BelumSeedDispersers_NetworkSpeciesInfo.xlsx Readme_Ong et al. 2021 The indices were computed from the seed dispersal matrix (https://doi.org/10.5061/dryad.jm63xsjbh) using the <i>bipartite </i>package (Dormann et al. 2021). This matrix contains seed dispersal interactions collected largely based on local ecological knowledge provided by the indigenous people of the Belum rainforest in Peninsular Malaysia, Sundaic region.