Increased bird sound diversity in vineyards enhances visitors' tour experience

1. Biodiversity is rapidly declining, reducing the quantity and quality of human interactions with nature and constraining its contribution to human health and well-being. Natural sounds are a key component of our experience of nature, but biodiversity losses are reflected in soundscapes, which are becoming less diverse and quieter.

2. We characterised the soundscapes across 21 English vineyards using acoustic indices and related them to bird species richness and abundance. We found that higher bird species richness, but not abundance, led to more diverse and louder soundscapes, as reflected in higher values of Acoustic Complexity Index (ACI), Bioacoustic Index (BIO) and Normalised Difference Soundscape Index (NDSI), and lower values of Acoustic Entropy Index (H).

3. Secondly, at three of the study vineyards that run vineyard tours, we measured visitors' experience of the tour in terms of sound enjoyment, soundscape connectedness and tour satisfaction and related these to ambient and experimentally enhanced soundscapes, where we used playback recordings of five additional birdsongs to increase the soundscapes' complexity and volume.

4. Under ambient conditions, respondents' (n = 107) experience was significantly higher at sites with soundscapes that had higher ACI and BIO values, and lower H, Acoustic Diversity Index (ADI) and NDSI values, indicating a positive effect of more diverse and louder soundscapes. Natural sounds formed an important part of the tour experience at these sites, making visitors feel more present and connected to nature.

5. Under experimental soundscape enhancement, respondents (n = 79) reported hearing significantly more bird species during the tour, and they reported significantly higher scores for sound enjoyment, soundscape connectedness and tour satisfaction than under ambient conditions. This effect was stronger in visitors who engaged more in pro-environmental behaviours, such as purchasing organic foods.

6. Our study demonstrates (i) the direct contribution of aural modes to our experience of nature and (ii) that the delivery of biodiversity conservation measures aimed at supporting bird diversity could simultaneously enhance the experience and well-being benefits of spending time in nature. Natural soundscapes should therefore be recognised and valued as natural capital, and their protection should be incorporated into conservation planning and policy.