idw – Informationsdienst Wissenschaft

Nachrichten, Termine, Experten

Grafik: idw-Logo
Grafik: idw-Logo

idw - Informationsdienst
Wissenschaft

Science Video Project
idw-Abo

idw-News App:

AppStore

Google Play Store



Instanz:
Teilen: 
15.08.2025 17:00

In the blink of an eye: How river noise shapes the dipper’s silent signals

Dr. Sabine Spehn Kommunikation (PR)
Max-Planck-Institut für biologische Intelligenz

    • Switching senses: Instead of just singing louder when the river roars, white-throated dippers lower their volume and start blinking their bright white eyelids more – using sight instead of sound to get their message across when other birds are nearby.
    • Context matters: Dippers change how they communicate in real time depending not just on the noise around them, but also on whether they have an audience – showing an unusual level of behavioral flexibility.
    • Evolutionary clues: Researchers say this is one of the clearest examples yet of a wild animal switching between senses to communicate, offering new insights into how animals adapt their signals to challenging environments.

    As anyone who has tried to hold a conversation in a noisy room knows, it is sometimes easier to rely on hand gestures than to shout over the din. White-throated dippers face a similar challenge along the fast-flowing streams they inhabit, where the roar of fast-flowing waters can sometimes drown out their melodic songs. Rather than trying to out-sing the river to defend territory or attract mates, these plump, endearing birds sometimes switch strategy entirely – turning to sight instead of sound, by flashing their bright white eyelids in a striking visual display.

    A new study led by researchers from the Max Planck Institute for Biological Intelligence and Lancaster University is among the first to document this kind of sensory shift in a wild bird. The findings shed light on how dippers adapt their communication depending on social and environmental cues – and how such flexibility may have evolved in response to noise.

    Being seen to be heard

    In the upland areas where white-throated dippers live, their varied, high-pitch metallic song is one of the earliest signs of spring. Sometimes seen perched on river rocks or skimming low over the water, these birds make their homes beside fast-flowing streams – ideal for feeding, but often difficult for communication, especially after heavy rains.

    In a recent study of wild dippers in Britain’s Yorkshire Dales National Park, published in Current Biology, researchers found that when river noise increases and other dippers are nearby, the birds don’t necessarily raise their voices. Instead, they may blink more conspicuously, fluttering their white-feathered eyelids, which stand out against their dark-brown plumage. These visual cues, the authors suggest, may help attract mates or signal presence to rivals that might otherwise miss them – and reveal how the birds can fine-tune their use of sound and sight in real time to navigate their noisy world.

    “Dippers don’t just add visual signals on top of their songs – they seem to switch between them depending on the situation,” says Léna de Framond, first author of the study. “When the river gets louder and other birds are nearby, they blink more often. We even found that birds that blink most often don’t sing as loud– suggesting a shift to visual communication. But when they are alone, we saw they actually tend to sing louder to rise above the noise. That contrast tells us the behavior is social, not just a response to sound, and is a rare example of a noise-induced multimodal shift in a wild animal.”

    Evolution shaped by river noise

    Using more than one sense to communicate can be a big advantage in noisy environments. However, while many animals are known to adapt within a single sense – for example, by singing louder, changing pitch, or repeating themselves – clear evidence of animals switching between senses to send messages, like moving from sound to sight, or touch to smell, is still surprisingly rare.

    The white-throated dipper made an ideal test case: it lives year-round beside fast-flowing rivers, where background noise is often high, and it has bright white eyelids that can act as a visual signal. If any species had learned to shift between senses to get its message across, the researchers reasoned, the dipper would be a great candidate.

    The team spent more than 300 hours observing wild dippers, some marked with colored rings for identification. Through detailed observations, calibrated audio recordings, and statistical analysis, they uncovered one of the clearest examples yet of animals switching between senses to communicate.

    “The study sheds light not just on how dippers communicate, but on how environmental challenges – like noisy rivers – can shape the evolution of signaling,” says Henrik Brumm, whose group at the Max Planck Institute for Biological Intelligence led the research. “What’s particularly interesting is the complexity of the dipper’s behavior and its ability to adapt to changing conditions.

    “It also raises new questions about how species balance clarity and complexity. More signals can help get attention, but also increase the risk of being misunderstood – and signals need to match the senses of the animals they’re meant for. Now that we’ve seen this ability in dippers, it suggests that switching between senses may be more common in nature than we realize. In that sense, we may be seeing just the tip of the iceberg – and it’s exciting to think about where this research could go next.”


    Wissenschaftliche Ansprechpartner:

    Dr. Henrik Brumm
    Research Group Leader
    MPI for Biological Intelligence
    Henrik.brumm@bi.mpg.de


    Originalpublikation:

    Stream noise induces song plasticity and a shift to visual signals in a riverine songbird
    Léna de Framond, Stuart P. Sharp, Kevin Duclos, Thejasvi Beleyur, Henrik Brumm
    Current Biology, online 15. August 2025


    Weitere Informationen:

    https://www.bi.mpg.de/brumm - Research group website


    Bilder

    At noisy rivers, dippers start blinking their white eyelids instead of singing louder. This is an impressive example of how animals use multiple senses to communicate, switching between them depending on the situation.
    At noisy rivers, dippers start blinking their white eyelids instead of singing louder. This is an im ...

    Copyright: © Kevin Duclos


    Merkmale dieser Pressemitteilung:
    Journalisten, Lehrer/Schüler, Studierende, Wissenschaftler, jedermann
    Biologie, Umwelt / Ökologie
    überregional
    Forschungsergebnisse, Wissenschaftliche Publikationen
    Englisch


     

    Hilfe

    Die Suche / Erweiterte Suche im idw-Archiv
    Verknüpfungen

    Sie können Suchbegriffe mit und, oder und / oder nicht verknüpfen, z. B. Philo nicht logie.

    Klammern

    Verknüpfungen können Sie mit Klammern voneinander trennen, z. B. (Philo nicht logie) oder (Psycho und logie).

    Wortgruppen

    Zusammenhängende Worte werden als Wortgruppe gesucht, wenn Sie sie in Anführungsstriche setzen, z. B. „Bundesrepublik Deutschland“.

    Auswahlkriterien

    Die Erweiterte Suche können Sie auch nutzen, ohne Suchbegriffe einzugeben. Sie orientiert sich dann an den Kriterien, die Sie ausgewählt haben (z. B. nach dem Land oder dem Sachgebiet).

    Haben Sie in einer Kategorie kein Kriterium ausgewählt, wird die gesamte Kategorie durchsucht (z.B. alle Sachgebiete oder alle Länder).