Researchers at the University of Gttingen analysed 6.4 million sounds from 53 European forest bird species across 256 locations in Lower Saxony, Germany, between March and May, utilising artificial intelligence to reveal inaccuracies in existing expert knowledge regarding birdsong activity. The study, published in the Journal of Ornithology, identified distinct vocal patterns, demonstrating that species like blackbirds and woodcocks are active around dawn and twilight, and that traditional survey times often fail to coincide with peak activity. Findings have already been incorporated into the latest edition of Methodenstandards zur Erfassung der Brutvgel Deutschlands, improving future research planning.
AI Reveals Nuances in Birdsong Activity
The research team analysed vocal activity patterns of 53 European forest bird species during a breeding season, collecting data from 256 forest locations in Lower Saxony, Germany, using automatic audio recorders operating continuously from March to May. These recorders captured 30-second recordings every 10 minutes, amassing a total of 6.4 million recorded sounds for analysis. The artificial intelligence identified bird species based on their calls and songs, and researchers subsequently verified the accuracy of these identifications to ensure data reliability.
Analysis revealed that forest bird species exhibit individual activity patterns, extending beyond the commonly recognised activity of larks and owls. Several species, including blackbirds and woodcocks, were found to be active around dawn and twilight, sometimes vocalising twice daily. Notably, blackbirds demonstrated significantly higher vocal activity in the evening compared to the morning, a finding not previously observed in standard bird counts.
Within the daytime active species, further subgroups were identified based on peak activity periods. While tits and the black woodpecker were most vocal in early spring, with activity declining from late April, species like the dunnock and wren became more active in April. Nocturnal species and migratory birds, arriving in Central Europe in May, formed distinct groups identified through the analysis of birdsong monitoring technology.
Comparison of the findings with existing methodologies for breeding bird surveys revealed that recommended survey times often did not coincide with peak song activity for many species. The great spotted woodpecker, previously assumed to be readily detectable throughout the morning, is demonstrably less vocal two hours after sunrise than shortly after. Similarly, the blue tit and chiffchaff continued to exhibit high vocal activity beyond the traditionally recommended morning recording period, indicating reliable detection is possible later in the day.
Grey-headed and lesser spotted woodpeckers, detectable only within a limited time window, are particularly well-suited to this new methodology, offering improved detection rates compared to traditional observation. The study’s results have already been incorporated into the latest edition of Methodenstandards zur Erfassung der Brutvgel Deutschlands, improving future research planning. Ongoing research projects may facilitate a comparable evaluation of bird species in agricultural landscapes.
Challenging Established Survey Methods
The findings of this study challenge established methodologies for breeding bird surveys, demonstrating that recommended survey times often do not coincide with peak song activity for numerous species. Specifically, the research indicates that the great spotted woodpecker exhibits demonstrably less vocalisation two hours after sunrise compared to shortly after, contradicting previous assumptions regarding its consistent detectability throughout the morning. Similarly, the blue tit and chiffchaff demonstrated continued high vocal activity beyond the traditionally recommended morning recording period, suggesting reliable detection remains possible later in the day.
This new methodology, utilising analysis of birdsong monitoring technology, proves particularly effective for species with limited activity windows, such as the grey-headed and lesser spotted woodpeckers, offering improved detection rates compared to traditional observation methods. The study’s results have already been integrated into the latest edition of Methodenstandards zur Erfassung der Brutvgel Deutschlands, signifying an immediate impact on future research planning and methodological standards. Further research projects are planned to evaluate comparable bird species within agricultural landscapes, extending the scope of this investigation.
Implications for Biodiversity Monitoring
This research forms part of the biodiversity monitoring programme of the Nordwestdeutsche Forstliche Versuchsanstalt, conducted in collaboration with the University of Gttingen’s Forest Nature Conservation and Conservation Biology research groups. The study’s findings have been incorporated into the latest edition of Methodenstandards zur Erfassung der Brutvgel Deutschlands, directly influencing future research planning and methodological standards for recording breeding birds in Germany. Ongoing research projects are planned to facilitate a comparable evaluation of bird species in agricultural landscapes, potentially broadening the application of this methodology beyond forested environments.