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

Abstract

Birdsong has long been a subject of extensive research in the fields of ethology as well as neuroscience. Neural and behavioral mechanisms underlying song acquisition and production in male songbirds are particularly well studied, mainly because birdsong shares some important features with human speech such as critical dependence on vocal learning. However, birdsong, like human speech, primarily functions as communication signals. The mechanisms of song perception and recognition should also be investigated to attain a deeper understanding of the nature of complex vocal signals. Although relatively less attention has been paid to song receivers compared to signalers, recent studies on female songbirds have begun to reveal the neural basis of song preference. Moreover, there are other studies of song preference in juvenile birds which suggest possible functions of preference in social context including the sensory phase of song learning. Understanding the behavioral and neural mechanisms underlying the formation, maintenance, expression, and alteration of such song preference in birds will potentially give insight into the mechanisms of speech communication in humans. To pursue this line of research, however, it is necessary to understand current methodological challenges in defining and measuring song preference. In addition, consideration of ultimate questions can also be important for laboratory researchers in designing experiments and interpreting results. Here we summarize the current understanding of song preference in female and juvenile songbirds in the context of Tinbergen’s four questions, incorporating results ranging from ethological field research to the latest neuroscience findings. We also discuss problems and remaining questions in this field and suggest some possible solutions and future directions.

Birdsong and the Neural Regulation of Positive Emotion

“…Thus, the positive emotional state induced by these elements adaptively shapes female mating choices by promoting preferential responses to high quality males. The fact that birds are willing to work (i.e., hop onto perches or peck keys) to hear song playback also indicates that hearing song, in combination with other morphological and behavioral traits, social and environmental context, history and individual differences ( Kaplan, 2019 ; Fujii et al, 2022 ), may induce an anticipatory state of reward seeking in sexually motivated females. The positive emotional states induced by song likely in combination with these other variables also play a role in maintaining pair bonds in monogamous zebra finches, with operant responses to song reinforcement in females observed exclusively in response to a mate’s song ( Tokarev et al, 2017 ; Coleman et al, 2019 ; Day et al, 2019 ).…”

Song preferences predict the quality of vocal learning in zebra finches

“…Juveniles of these species must attend to signals, such as speech or song, in order to imitate them; the benefits of doing so are often seen in adulthood, once these signals can be used to share information 2 , attract a mate, or secure a territory 5 . Thus, learning these signals likely depends on being attracted to them at a time when those benefits of signaling are beyond reach 6,7 . There should, therefore, be a great deal of selection pressure on young learners to be attracted to these signals, even in the absence of immediate mating opportunities or food rewards.Songbirds lend themselves well to studying the processes by which attraction to song contributes to vocal learning.…”

Auditory processing neurons influence song evaluation and strength of mate preference in female songbirds

“…A long term goal should be to couple these techniques with a thorough knowledge of the female’s life experience. Females differ in what song they find most attractive (e.g., Dunning et al, 2014 ), and a female’s song preference and activity in auditory processing areas such as NC and CM can be affected by experience (reviewed in Fujii et al, 2022 ). Coupling detailed knowledge of a female’s life experience (e.g., reared in the laboratory under known acoustic and social conditions) with awake recording or optogenetic stimulation of activity in these auditory areas and their downstream targets holds the promise of revealing new insights into how this system processes sensory information in service of behavioral activation.…”

“…The behaviors expressed in songbird courtship and the circuits of the songbird brain provide an experimentally approachable context to characterize the links between neural activation and behavior (reviewed in Murphy et al, 2020 ; Fujii et al, 2022 ). In many songbird species, including the Bengalese finches (BF; Lonchura striata domestica ) studied here, adult males can sing but females cannot (Catchpole and Slater, 2008 ; Mooney et al, 2008 ), but recent studies have highlighted that female song is more common than was previously appreciated (Odom et al, 2014 ; Langmore, 2020 ).…”