Interspecific Hybridization as a Tool to Understand Vocal Divergence: The Example of Crowing in Quail (Genus Coturnix)

Understanding the mechanisms that lead organisms to be separated into distinct species remains a challenge in evolutionary biology. Interspecific hybridization, which results from incomplete reproductive isolation, is a useful tool to investigate such mechanisms. In birds, interspecific hybridization is relatively frequent, despite the fact that closed species exhibit morphological and behavioural differences. Evolution of behaviour is difficult to investigate on a large timescale since it does not ‘fossilize’. Here I propose that calls of hybrid non-songbirds that develop without the influence of learning may help in understanding the gradual process that leads to vocal divergence during speciation. I recorded crows produced by the European quail (Coturnix c. coturnix), the domestic Japanese quail (Coturnix c. japonica) and their hybrids (F1, F2 and backcrosses). Most crowing patterns were intermediate to those of the parental species; some were similar to one or the other parental species, or not present in either parental species. I also observed vocal changes in hybrid crows during the breeding season and from one year to the other. This vocal variability resembles those observed during the ontogeny of the crow in quails. It is likely that similar mechanisms involved in vocal changes during ontogeny might have driven vocal divergence in the species of Palearctic quails. I suggest that hybrid crows might have resembled those produced by intermediary forms of quails during speciation

Traffic noise disrupts vocal development and suppresses immune function

Noise pollution has been linked to learning and language deficits in children, but the causal mechanisms connecting noise to cognitive deficiencies remain unclear because experimental models are lacking. Here, we investigated the effects of noise on birdsong learning, the primary animal model for vocal learning and speech development in humans. We found that traffic noise exposure retarded vocal development and led to learning inaccuracies. In addition, noise suppressed immune function during the sensitive learning period, indicating that it is a potent stressor for birds, which is likely to compromise their cognitive functions. Our results provide important insights into the consequences of noise pollution and pave the way for future studies using birdsong as an experimental model for the investigation of noise-induced learning impairments

Birdsong learning in the laboratory

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Artificial song dialects in the Zebra Finch

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Le chant du Rossignol Philomèle (Luscinia megarhynchos): du terrain au laboratoire

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Ontogeny of behaviour

International audienceOntogeny refers to the developmental course of an organism. Here we focus on ontogeny of behavior. In both humans and other animals, movements and sensorimotor integration together with reaction to external environmental stimuli can be measured several days or even several months before birth or hatching. Recent developments in epigenetics show that environmental stimuli experienced both by the parents and the embryo have long lasting effects for the next generations. Genetic determinism and early experience may shape individual behavior of animals leading to consistent inter-individual differences or personality profiles. Early life is sensitive to social learning, including imprinting and other forms of learning mediated by brain mechanisms, orchestrated by hormones and biological rhythms, and ending with sexual maturity. Behavioral changes can also occur during senescence and for instance old post-reproductive animals can play a significant role, such as the grandmother effect

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Data from: Horizontal transmission of the father’s song in the Zebra Finch (Taeniopygia guttata)

As is the case for human speech, birdsong is transmitted across generations by imitative learning. Although transfer of song patterns from adults to juveniles typically occurs via vertical or oblique transmission, there is also evidence of horizontal transmission between juveniles of the same generation. Here, we show that a young male zebra finch (Taeniopygia guttata) that has been exposed to its father during the sensitive period for song learning can lead a brother, that has never heard the paternal song, to imitate some sounds of the father. Moreover, song similarity between the two brothers was higher than the similarity measured between the paternal song and the song of the brother that had a week-long exposure to the father. We speculate that the phenomenon of within-generation song learning among juveniles may be more widespread than previously thought and that when a juvenile evaluates potential models for imitative learning, a sibling may be as salient as an adult

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