Auditory and sexual preferences for a father’s song can co-emerge in female Bengalese finches

Abstract

Birdsong is an important communication signal used in mate choice. In some songbird species, only the males produce songs. While the females of those species do not sing, they are sensitive to inter- and intra-species song variations, and the song preferences of females depend on their developmental experiences and/or genetic predispositions. For example, in Bengalese finches and zebra finches, adult females prefer the song to which they were exposed early in life, such as the father’s song. In the current study, we aimed to test whether the preference for the father’s song, as reported in previous Bengalese finch studies, can be interpreted as a mating preference. For this purpose, the subjects were raised exclusively with their family until they became sexually mature and then tested as adults. We measured copulation solicitation displays during playbacks of the father’s song vs. unfamiliar conspecific songs and found that across individuals, the father’s song elicited more displays than other songs. In addition, we analyzed if a bird’s response to a given song could be predicted by the level of similarity of that song to the father’s song. Although the birds expressed more displays to songs with greater similarity to the father’s song, the effect was not statistically significant. These results suggest that female Bengalese finches can develop a strong mating preference for the father’s song if they are exclusively exposed to the father’s song early in life. However, it is not clear if such a preference generalizes to other cases in which birds are exposed to multiple male songs during development. In order to fully elucidate the possible contribution of experience and genetic factors in the development of female song preference in this species, future studies will need more detailed manipulation and control of the rearing conditions, including cross-fostering.

Song Preference in Female and Juvenile Songbirds: Proximate and Ultimate Questions

“…As this would not always be very practical, an alternative way is to examine the correlation between behavioral indices in laboratory experiments. As such, in a series of studies of female Bengalese finches, the response rate of a specific call type was positively correlated with CSDs as well as with phonotaxis at an individual or a population level ( Kato et al, 2010 ; Dunning et al, 2014 ; Fujii et al, 2021 ; Fujii and Okanoya, 2022 ). Because using multiple behavioral tests to measure subjects within a single study can be logistically challenging, the most practical approach may be to gradually accumulate the results from an entire research community over time.…”

“…For instance, in the studies on Bengalese finches from our laboratories, we found that while some song features are preferred by majority of females, there are also substantial individual differences in the song preference ( Morisaka et al, 2008 ; Kato et al, 2010 ; Dunning et al, 2014 , 2020 ). Other studies provide a possibility that the source of individual variation lies in the early-life experience of father’s song ( Fujii et al, 2021 ; Fujii and Okanoya, 2022 ). As the Bengalese finch song is particularly interesting for the sequential complexity and its evolutionary change through domestication process ( Okanoya, 2004a ; Okanoya, 2004b ), scrutinizing the universality and individual differences of female song preference from the perspectives of neural mechanisms and development potentially help investigate the function and evolution of the sequential complexity, and vice versa.…”

“…This exclusion of facets of communication other than song can be accomplished by recording the songs produced by male birds and playing them through a speaker when no male is physically present. Song is an especially impactful stimulus in female evaluation of the quality of the male suitor, and song is sufficient to drive female courtship and copulatory behaviors even when no male is present ( Woolley and Doupe, 2008 ; Caro et al, 2010 ; Dunning et al, 2014 , Dunning et al, 2020 ; Heinig et al, 2014 ; Perkes et al, 2019 , Perkes et al, 2021 ; Fujii and Okanoya, 2022 ). Thus, song is a unimodal stimulus that facilitates investigations of how the qualities of that stimulus affect female evaluation of the quality of those signals.…”

“…A recent study showed that the father’s song can be a strong stimulus in eliciting CSDs in female Bengalese finches. ( Fujii and Okanoya, 2022 ). If the father’s song is consistently the female’s most preferred song, that could have detrimental effects on fitness.…”

Song preferences in female Java Sparrows: Familiarity or Complexity?

“…For all behaviours measured, the direction of effect was towards a stronger response to familiar non-father songs compared to unfamiliar songs.. A wide range of song features, including song and note structure, are socially inherited in this species (Lewis et al, 2021a), meaning that song type and song similarity likely indicate that birds are (socially) related. There is some evidence for generalization of preference from other Estrildid finch species, with birds showing greater responses to songs that were more similar to those of their father (Fujii and Okanoya, 2022; Miller, 1979; Wei et al, 2022). However, this is not the case in all studies.…”