Figure 2. Scale-dependent sampling effects on phylogenetic distance. (A-B) Nearest phylogenetic distance (NPD) of introduced species (63 species successfully established in 50 regions Worldwide) to native species estimated at different spatial scales; (C) species randomly sampled from the entire avian phylogeny (n=9,993), the subset that has been introduced in regions outside their native range (n=962) and those from the subset that have become successfully established in the new region (n=443); and (D-E) species of the biogeographic realm from where most introduced species originated (Palearctic) and realms where those have more frequently been introduced (Nearctic and Australian). Codes: IC = invaded communities, NIC = non-invaded communities, REG = regional level, COU = country and CON = continental.