Data from: Elucidating mutual mate choice

Understanding the dynamics of mutual mate choice requires investigation of
mate preferences of both sexes using a variety of designs, but fewer
studies have focused on male choice in avian models. Here we conducted two
experiments on preferences of male zebra finches to study the impact of
trial design on results. Experimental design varied in number of
trial participants, inclusion of observer (“audience”) males, and housing
design for stimulus females. Females were reared on one of two
diets to enhance variation in mating quality: those reared on a
protein-supplement diet (HI-diet) were predicted to be more attractive to
males than (LO-diet) females that did not receive
supplements. Results differed among trial
types. Notably, males showed the predicted preference for HI-diet
females only in the Group Choice experiment, where two male subjects
simultaneously chose from a field of four females, and all six birds
interacted freely. In the Dyadic Preference (DP) experiment, a
single male was allowed to interact with two stimulus females that were
physically isolated; in half of these trials, audience males were
present. In DP trials without audience males, test males did not
express a preference consensus; however, with audience males present, test
males preferred LO-diet females. Results are consistent with a
small but growing literature indicating that results of mate choice
experiments can be highly sensitive to design considerations.