Consistency and flexibility in the scrounging behaviour of zebra finches

When foraging in groups, individuals can use the "producer" tactic to locat e food patches and the "scrounger" tactic to exploit the food discoveries o f companions. Most producer-scrounger models assume that birds are flexible in using tactics in response to changing conditions and that foragers are phenotypically identical. Individual differences and flexibility in tactic use were investigated in zebra finches (Taenopygia guttata) foraging in two flocks of different composition. Birds varied widely in their use of tacti cs, and individual differences proved consistent both within and between fl ocks. Significant adjustments in tactic use occurred from one flock to the other. Results suggest that tactic use in zebra finches foraging in small f locks is characterized by consistency and flexibility. Individual differenc es in tactic use demonstrate the need to examine further the consequences o f phenotypic variation in producer-scrounger models.