Competition for resources mediated by intrinsic social dominance in sympatric finches

Gouldian E rythrura gouldiae and L ong‐tailed F inches P oephila acuticauda are morphologically and ecologically similar sympatric species, for which social dominance relationships are likely to determine access to critical limiting resources. Building on previous research showing that L ong‐tailed F inches dominate competition for nest‐sites, I staged dyadic contests for food between the two species in captivity in order to test social dominance dynamics under controlled conditions. L ong‐tailed F inches were likely to dominate interactions with G ouldian F inches and expressed higher levels of aggression while competing for access to food. These results suggest a stable dominance relationship between the two species which could be affecting G ouldian F inches' access to food resources in the wild, potentially constraining their ability to recover from recent population declines.