The diverse nature of island isolation and its effect on land-bridge insular faunas

Aim Isolation is a key factor in island biology. It is usually defined as the distance to the geographically nearest mainland, but multiple alternatives exist. We explored how testing different isolation indices affects the inference of isolation effects on faunal characteristics. We focused on land-bridge islands and compared the relationships of multiple spatial and temporal (i.e., through time) isolation indices with community-, population-, and individual-level characteristics (species richness, population density, and body size, respectively).

Location Aegean Sea islands, Greece.

Time period: current.

Taxon Multiple animal taxa.

Methods We estimated 21 isolation indices for 205 islands, and recorded species-richness data for 15 taxa (invertebrates and vertebrates). We obtained body size data for seven lizard species and population density data for three. We explored how well indices predict each characteristic, in each taxon, by conducting a series of OLS regressions (...