Innovative Individuals Are Not Always the Best Demonstrators: Feeding Innovation and Social Transmission in Serinus canaria

BACKGROUND Feeding innovation occurs when individuals choose a novel, unknown type of food and/or acquire new feeding skills. Here we studied feeding innovation and social transmission of the new feeding habit in canaries. Adult canaries eat a wide variety of seeds but avoid larger ones such as those of sunflowers. We determined whether adults of both sexes are equally prone to innovate when confronted with sunflower seeds and whether free-interactions facilitate transmission of the new feeding habit in a sex-dependent manner. METHODOLOGY/PRINCIPAL FINDINGS First we determined which sex was more innovative, i.e., was more successful at husking and eating the novel seeds. Males were clearly more innovative than females. Due to this, experienced males served as model for either male or female observers in three different conditions (free interaction with a demonstrator, visual interaction with a demonstrator placed behind a transparent wall and access to seeds in the presence of a non-demonstrating bird). During free interactions, the new feeding habit was only transmitted to females. In contrast, transmission of seed handling to male observers only occurred if demonstrator and observer were separated by the transparent wall. Indeed, aggressive behaviors between males prevented social transmission during free interactions. Finally, we studied the influence of the less innovative females in feeding-habit transmission. First, we obtained female demonstrators by making them freely interact with male demonstrators. Once they acquired innovative responses to sunflower seeds we studied feeding-habit transmission towards male and female observers. Observers of both sexes learned during free interactions with female demonstrators. No aggressive behavior occurred. Males were also able to learn after visual interactions with the female demonstrator. CONCLUSIONS/SIGNIFICANCE Our results show that the most innovative individuals (males) are not always the best demonstrators, and that social relationship and sex are crucial factors for the spread of a new feeding habit among canaries. These factors determine the kind of interaction between individuals and the time spent together, thus affecting the transmission of novel habits within the population.