“Rapid assessment of avian species richness and abundance using acoustic indices” – New paper with @bunnefeld @_birdyNick @SWillis_Durham @DaisyDent –authors.elsevier.com/sd/article/S14…
#Birds #Bioacoustics & #Conservation See thread to find out more 1/10
#Birds #Bioacoustics & #Conservation See thread to find out more 1/10
An acoustic index is a metric derived from audio recordings, simplifying the complexity of sound into a single number. If we can find associations between acoustic indices and classic biodiversity metrics like species richness, it could facilitate monitoring on a huge scale. 2/10
In our paper, we show consistent and coherent links between nine different acoustic indices and avian species richness and relative abundance. 3/10
In general, sites with more birds have less even soundscapes, i.e. greater variation over time and especially among frequencies. 4/10
This has been tried before, but most find no link between acoustic indices and bird species richness and abundance. We suggest this is because of conceptual and methodological issues. Three things make our approach different:
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1. We treat acoustic indices as site properties, akin to net primary productivity. Direct links between concurrent recordings and bird counts are unlikely without huge datasets and would have a lot of (statistical) noise.
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1 continued. This is because birdsong is irregular within & among species, affected by animals’ distance to the microphone, by habitat structure, & by other sources of biophony & geophony. 7/10
2. We focussed on the dawn chorus, when birds are contributing the most to the soundscape, but used continuous recordings to capture as much variation as possible. Sub-sampling would mean it took longer to gather enough data. 8/10
3. Acoustic indices values are usually bounded and highly skewed, we used statistical approaches that can cope with these types of data. 9/10
Will this pattern hold in other parts of the tropics? Or in temperate regions? We need more research! Hopefully useful for those working in #Conservation, #Bioacoustics & #acousticecology 10/10
