Arctic migrations shape global meta-communities: Contrasting insights from species occurrence, abundance and biomass

Aim: Seasonally migratory species generate large movements of organisms and biomass between distant breeding and non-breeding grounds. However, our understanding of how migratory species shape global networks of interconnected communities (meta-communities) remains limited. Migratory links between communities can be measured in different ways (e.g., species occurrence, abundance or biomass), each providing complementary information by modulating the relative importance of species in meta-communities. We aim at investigating to what extent measuring migratory links using species occurrence, abundance or biomass can reveal alternative structures (i.e., topology) in a meta-community linking an Arctic breeding ground to remote non-breeding grounds. 

Location: We use as a study case the High-Arctic vertebrate community of Bylot Island (Nunavut, Canada), along with ecoregions of North and South America, Europe and Africa. 

Time period: Present. 

Major taxa studied: Terre..., Species abundance and biomass: The mean summer abundance and biomass of all vertebrate species in the Bylot Island community were estimated from the long-term ecological monitoring program (see Moisan et al., 2025). 
Species non-breeding range: We used the previously defined non-breeding ranges of all migratory and partially migratory species of Bylot Island (see Moisan et al., 2023) derived from tracking of individuals (6 species; Gilchrist, Mosbech and Sonne, 2004; Therrien, Gauthier and Bêty, 2012; Robillard, Gauthier, Therrien and Bêty, 2018; Léandri‐Breton, Lamarre and Bêty, 2019; LeTourneux et al., 2021; Seyer, Gauthier, Bêty, Therrien and Lecomte, 2021; Lamarre et al., 2021) and refined species range maps (BirdLife International and Handbook of the Birds of the World, 2019; Fink et al., 2021).
Ecoregions of the world: We used the classifications of terrestrial (Olson et al., 2001), marine (Spalding et al., 2007) and freshwater ecoregions (only for large bodies..., , # Arctic migrations shape global meta-communities: Contrasting insights from species occurrence, abundance and biomass

### Access data and codes

#### Data: [https://doi.org/10.5061/dryad.1vhhmgr4m](https://doi.org/10.5061/dryad.1vhhmgr4m)

#### Codes and R project: [https://doi.org/10.5281/zenodo.14605503](https://doi.org/10.5281/zenodo.14605503)

### **Structure of the R project**

#### data/metadata/

* *species_metadata.csv*: Species taxonomy and selected data to define the range and abundance index of species during the non-breeding period.
            -*class*: Taxonomic class for birds (Gill et al., 2024) and mammals species (Upham et al., 2024).
            -*order*: Taxonomic order for birds (Gill et al., 2024) and mammals species (Upham et al., 2024).
            -*family*: Taxonomic family for birds (Gill et al., 2024) and mammals species (Upham et al., 2024).
            -*genus*: Taxonomic genus for birds (Gill et al., 2024) and mammals species (Upham et al., 2024)...,