Social inhibition of song imitation among sibling male zebra finches

Abstract

A male zebra finch, Taeniopygia guttata, kept with its father until adulthood develops an imitation of its father's song motif. We report here that the completeness of this imitation was sensitive to the social or auditory context in which the bird grew up: the greater the number of male siblings in a clutch, the shorter the mean duration of the song motif and the fewer the mean number of song notes imitated from the father; the latter shortfall was not compensated by other, improvised notes. We call this effect fraternal inhibition. Fraternal inhibition was avoided by members of a clutch that developed the song first. To our surprise, this role commonly fell to one of the younger birds in the clutch. Early song learning may inf luence fitness since individuals that produced the most complete imitations also tended to induce more egg laying.Song learning in songbirds has provided classical material to demonstrate how the predispositions that members of different species bring to a learning task affect the ''when" and ''what'' of learning. Initially, much attention was devoted to the nature of the songs imitated and to the sensitive period when this occurred (1-3). Subsequently, it was shown that other variables could matter too, as when Baptista and Petrinovich (4) emphasized that live models can be more effective than playbacks, or when King and West (5) described the importance of female responses in coaching the development of male song, or when Williams (6) described the extent to which an individual borrowed material from more than one tutor. Our study adds a new facet to this well-established field in that it looks at the influence of the family milieu on vocal learning, using as an example a very social species, the zebra finch.Song develops in male zebra finches during the first 90 days after hatching and a relatively stable adult song is in place by the end of that period, which coincides with the onset of sexual maturity (7). Even though different male zebra finches can produce songs that are quite dissimilar, the songs of father and son are remarkably alike when the son grows up in the company of its father. This close similarity is not determined by genetic relatedness because juvenile zebra finches can develop an accurate imitation of a foster father's song, even when the foster father is a member of a different species (8, 9).We investigated song imitation in clutches with different numbers of male siblings. We show that (i) the greater the number of male siblings in a clutch, the shorter the mean duration of their song motif and the fewer the mean number of song notes imitated from the father; (ii) the order in which male siblings from the same clutch hatched was inversely related to the completeness of imitations and song duration; (iii) individuals that produced more complete imitations tended to induce an earlier ovulation response in females than was the case for males with less complete imitations. We do not know how these observations apply to vocal learning in free-ranging zebra fin...

How social learning adds up to a culture: from birdsong to human public opinion

“…However, in a family setting, where a few siblings are interacting with a single tutor (their father), typically only one of them (the first one to imitate the father's song) will develop an accurate imitation. In the other siblings, song imitation is partially inhibited, resulting in divergence (Tchernichovski and Nottebohm, 1998). This is not due to lack of opportunity to learn from a busy tutor: a recent study showed that the rate at which tutors produced song is inversely related to pupil attention and to song learning (Chen et al, 2016).…”

“…But errors in song imitation are not entirely random: the accuracy of song imitation varies with environmental (Nowicki et al, 2002) and social (Chen et al, 2016;Tchernichovski and Nottebohm, 1998) conditions. Furthermore, there is evidence that the accuracy of song imitation may change adaptively -i.e.…”

Quantification of developmental birdsong learning from the subsyllabic scale to cultural evolution

“…Songbirds learn their songs by imitating an adult tutor. Imitation increases song similarity within a group, but there are also divergent forces (68) that drive considerable variability in song among individuals; moreover, there are regional dialects among groups of birds from the same species (69). Thus, birds have a song culture that develops over generations.…”

Where Apes and Songbirds are Left Behind: A Comparative Assessment of the Requisites for Speech

“…Conversely, many songbirds learn their vocalizations directly and indirectly through hearing aggressive, territorial interactions of their fathers and neighboring conspecifics (e.g., Nuttall's white-crowned sparrows, Zonotrichia leucophyrys nuttali, Bell, Trail, & Baptista, 1998;European starlings, Bertin, Hausberger, Henry, & Richard-Yris, 2007;zebra finches, Zann, 1990). In zebra finches, presence and interactions with even male siblings can contribute to features of a male's song (e.g., Tchernichovski, Lints, Mitra, & Nottebohm, 1999;Tchernichovski & Nottebohm, 1998).…”