The effect of prior residence and pair bond on scrounging choices in flocks of zebra finches, Taenopygia guttata.

In groups, animals can use the producer tactic to locate food patches and the scrounger tactic to join the food discoveries of other companions. At equilibrium, models predict a mixture of the two tactics with equal payoffs. Several factors may constrain the use of tactics and lead to biases in scrounging choices. I explored the effect of prior residence and pair bond as potential constraints on scrounging choices in flocks of zebra finches (Taenopygia guttata). Experimental flocks contained two birds already established in an aviary (prior residents) and two birds recently released in the aviary for the first time (new residents). All birds were previously trained to find food on a foraging grid. In the aviary, new residents followed prior residents from perches to the grid and relied heavily on prior residents to locate food patches. Low initial success by new residents probably favoured heavy reliance on the scrounger tactic. New residents that formed pair bonds with prior residents foraged closer to their mates and scrounged selectively from their mates in some cases. Prior residence, and pair bond to a lesser extent, influenced scrounging choices in zebra finches and could lead to deviation from the expected use of foraging tactics.