Bill measurements of hummingbirds in the ecological network database

Here you will find the bill measurements of 161 hummingbird species. This is the set of species present in the network database that describes the interactions between these hummingbirds and their nectar resources (Dalsgaard et al. 2011, Martin-Gonzalez et al. 2015, Maruyama et al. 2018, Sonne et al. in press). Detailed information about the measurements can be found at the enclosed documents

Visitation and pollen matrices

Matrices used to interaction network analysi

Rasters associated with Sandel et al. 2011 -- converted

This version of the data file has undergone format conversion by a Dryad curator

Rasters associated with Sandel et al. 2011

This is the file originally uploaded by the author

Supplemental Material from Habitat fragmentation increases specialization of multi-trophic interactions by high species turnover

Habitat fragmentation is altering species interactions worldwide. However, the mechanisms underlying the response of network specialization to habitat fragmentation remain unknown, especially for multi-trophic interactions. We here collected a large dataset consisting of 2670 observations of tri-trophic interactions among plants, sap-sucking aphids and honeydew-collecting ants on 18 forested islands in the Thousand Island Lake, China. For each island, we constructed an antagonistic plant-aphid and a mutualistic aphid-ant network, and tested how network specialization varied with island area and isolation. We found that both networks exhibited higher specialization on smaller islands, while only aphid-ant networks had increased specialization on more isolated islands. Variations in network specialization among islands was primarily driven by species turnover, which was interlinked across trophic levels as fragmentation increased the specialization of both antagonistic and mutualistic networks through bottom-up effects via plant and aphid communities. These findings reveal that species on small and isolated islands display higher specialization mainly due to effects of fragmentation on species turnover, with behavioural changes causing interaction rewiring playing only a minor role. Our study highlights the significance of adopting a multi-trophic perspective when exploring patterns and processes in structuring ecological networks in fragmented landscapes

Original data and codes.rar from Habitat fragmentation increases specialization of multi-trophic interactions by high species turnover

Habitat fragmentation is altering species interactions worldwide. However, the mechanisms underlying the response of network specialization to habitat fragmentation remain unknown, especially for multi-trophic interactions. We here collected a large dataset consisting of 2670 observations of tri-trophic interactions among plants, sap-sucking aphids and honeydew-collecting ants on 18 forested islands in the Thousand Island Lake, China. For each island, we constructed an antagonistic plant-aphid and a mutualistic aphid-ant network, and tested how network specialization varied with island area and isolation. We found that both networks exhibited higher specialization on smaller islands, while only aphid-ant networks had increased specialization on more isolated islands. Variations in network specialization among islands was primarily driven by species turnover, which was interlinked across trophic levels as fragmentation increased the specialization of both antagonistic and mutualistic networks through bottom-up effects via plant and aphid communities. These findings reveal that species on small and isolated islands display higher specialization mainly due to effects of fragmentation on species turnover, with behavioural changes causing interaction rewiring playing only a minor role. Our study highlights the significance of adopting a multi-trophic perspective when exploring patterns and processes in structuring ecological networks in fragmented landscapes

Data_and_code

To run the extinction models, first download the Stochastic Coextinction Model code from the Supplementary Information of Vieira and Almeida-Neto (2015) (see references). The script netcascade (April 2014).R is required for the analyses in this paper. The supplementary information contains three scripts: 1. Main.R – This script runs simulations on the 8 networks to calculate PE, SE and VE for each species in each network. 2. IterativeNodeDeletion.R – A wrapper around netcascade (April 2014).R that calls netcascade() repeatedly to iteratively remove species from the network. 3. IterNodeDelMultiSim.R – A wrapper around IterativeNodeDeletion.R that runs IterativeNodeDeletion() multiple times to account for the stochasticity in the netcascade() algorithm. And four datasets: 1. data/rvalues.csv – The expert-assigned dependency categories for each plant species in each network used to determine R values 2. data/webs – Folder containing the 8 interaction matrices 3. data/phylogeny - contains (1) a set of 1000 phylogenies for the 13 Caribbean hummingbird species that were analysed (Caribbean_Phylogenies_.nex), (2) the maximum clade credibility (MCC) phylogeny (Caribbean_MCC_Phylogeny.nex) 4. data/traits - species-level data for body mass and bill length If you use the extinction modelling code please cite the following two papers: 1. Dalsgaard et al. (in press) Trait evolution, resource specialisation and vulnerability to plant extinctions among Antillean hummingbirds. Proceedings of the Royal Society B. 2. Vieira, M.C. and Almeida‐Neto, M., 2015. A simple stochastic model for complex coextinctions in mutualistic networks: robustness decreases with connectance. Ecology Letters, 18(2), pp.144-152. doi: 10.1111/ele.12394 If you use the data please cite: Dalsgaard et al. (in press) Trait evolution, resource specialisation and vulnerability to plant extinctions among Antillean hummingbirds. Proceedings of the Royal Society B. References: Vieira, M.C. and Almeida‐Neto, M., 2015. A simple stochastic model for complex coextinctions in mutualistic networks: robustness decreases with connectance. Ecology Letters, 18(2), pp.144-152. doi: 10.1111/ele.1239

Supplementary Material from Trait evolution, resource specialization and vulnerability to plant extinctions among Antillean hummingbirds

Species traits are thought to predict feeding specialization and the vulnerability of a species to extinctions of interaction partners, but the context in which a species evolved and currently inhabits may also matter. Notably, the predictive power of traits may require that traits evolved to fit interaction partners. Furthermore, local abiotic and biotic conditions may be important. On islands, for instance, specialized and vulnerable species are predicted to be found mainly in mountains, whereas species in lowlands should be generalized and less vulnerable. We evaluated these predictions for hummingbirds and their nectar-food plants on Antillean islands. Our results suggest that the rates of hummingbird trait divergence were higher among ancestral mainland forms before the colonization of the Antilles. In correspondence with the limited trait evolution that occurred within the Antilles, local abiotic and biotic conditions—not species traits—correlate with hummingbird resource specialization and the vulnerability of hummingbirds to extinctions of their floral resources. Specifically, hummingbirds were more specialized and vulnerable in conditions with high topographical complexity, high rainfall, low temperatures and high floral resource richness, which characterize the Antillean Mountains. These findings show that resource specialization and species vulnerability to extinctions of interaction partners are highly context-dependent