Do female zebra finches prefer males exhibiting greater plasticity in foraging tactic use?

Abstract

There is ample evidence that phenotypic traits are important mate choice criteria. Yet, we still know little about the importance of behavioural plasticity in attracting mates, although females could gain direct and/or indirect fitness benefits by choosing males that can adjust their behaviour to environmental fluctuations. Plasticity in foraging tactic use, particularly, might be a key determinant of fitness that could guide mate choice. In this study, we thus asked whether female zebra finches (Taeniopygia guttata) prefer males exhibiting greater plasticity in their foraging tactic use. We measured individual plasticity in a producer–scrounger game where males and females, playing in turn, were exposed to two seed distribution treatments, and females could monitor the males’ behaviour, unbeknownst to them. Subsequently, we measured the time each female spent in front of the males they had previously observed in the expectation that females would exhibit a general preference for males with greater plasticity in tactic use. Contrary to our expectation, we found that females did not unanimously prefer the males exhibiting greater plasticity but differed widely in their preference with more plastic females showing a stronger preference for male plasticity compared to the other females. Thus, our findings suggest that differences among females in their mating preference would contribute to maintaining differences in plasticity in tactic use.

Significance statement

Mate choice is a crucial decision in an individual’s life that directly impacts its fitness. Given that females could benefit from choosing males capable of responding to changes in environmental conditions, we asked in this study whether female zebra finches (Taeniopygia guttata) prefer males exhibiting greater plasticity in their foraging tactic use. We let females observe males expressing plasticity in a social foraging context and scored their mate preference for male plasticity. We found that females differed in their preference for male plasticity in tactic use, with more plastic females exhibiting a stronger preference for male plasticity compared to the others. Our results indicate that behavioural plasticity may be used as a mate choice criterion and hence suggest that mate choice might contribute to maintaining differences in male behavioural plasticity.