Unravelling the Stability of Nightingale Song Over Time and Space Using Open, Citizen Science and Shared Data

Abstract

Open science approaches enable and facilitate the investigation of many scientific questions in bioacoustics, such as studies on the temporal and spatial evolution of song, as in vocal dialects. In contrast to previous dialect studies, which mostly focused on songbird species with a small repertoire, here we studied the common nightingale (Luscinia megarhynchos), a bird species with a complex and large repertoire. To study dialects on the population level in this species, we used recordings from four datasets: an open museum archive, a citizen science platform, a citizen science project, and shared recordings from academic researchers. We conducted to the date largest temporal and geographic dialect study of birdsong including recordings from 1930 to 2019 and from 13 European countries, with a geographical coverage of 2,652 km of linear distance. To examine temporal stability and spatial dialects, a catalog of 1,868 song types of common nightingales was created. Instead of dialects, we found a high degree of stability over time and space in both, the sub-categories of song and in the occurrence of song types. For example, the second most common song type in our datasets occurred over nine decades and across Europe. In our case study, open and citizen science data proved to be equivalent, and in some cases even better, than data shared by an academic research group. Based on our results, we conclude that the combination of diverse and open datasets was particularly useful to study the evolution of song in a bird species with a large repertoire.

Community engagement and data quality: best practices and lessons learned from a citizen science project on birdsong

“…Our opportunistic approach indeed led to a large collection of geo-referenced nightingale song recordings. We previously showed that the majority of our CS data were valid enough (Jäckel et al 2021 ) and of high value for dialect studies (Jäckel et al 2022 ). The development of the project over three nightingale breeding seasons has not yet been studied.…”

Geographic variations of song and rain calls of the Chaffinch across the ranges of three subspecies

“…Obviously, it is necessary for this that the song types, spreading to new areas, would remain unchanged in the original area of their distribution. The song types are known to persist in populations of some species for decades (Harbison et al 1999, Goodale & Podos 2010, O'Loghlen et al 2013, García et al 2015, Jäckel et al 2022. We have described the survival of many of the Chaffinch song types for 38 years (from 1982 to 2020) in the population of the Zvenigorodskaya Station (Ivanitskii et al 2023).…”

Wild nightingales flexibly match whistle pitch in real time

“… 14 , 15 Among them, the common nightingale ( Luscinia megarhynchos ) has been praised for centuries for its extraordinary singing behavior 16 , 17 , 18 ( Figure S1 A; Video S1 ). These birds have a seasonal repertoire 19 , 20 of 150–200 different songs 21 , 22 of which one acoustically distinct type is called “whistle songs.” These songs contain relatively unmodulated tonal “whistle syllables” ( Figures 1 A, 1B, and S2 A; and Audio S1 ) and are used in long-range counter-singing duels for territorial defense and mate attraction. 23 , 24 , 25 To quantitatively investigate whether nightingales perform real-time identification and reproduction of the pitch of heard whistle syllables, we performed song recordings of pairs of naturally interacting male nightingales during their mating season in Germany and playback experiments both during their mating season in Germany and in nightingales’ wintering quarters in The Gambia.…”