RESUMO
Natural sounds, and bird song in particular, play a key role in building and maintaining our connection with nature, but widespread declines in bird populations mean that the acoustic properties of natural soundscapes may be changing. Using data-driven reconstructions of soundscapes in lieu of historical recordings, here we quantify changes in soundscape characteristics at more than 200,000 sites across North America and Europe. We integrate citizen science bird monitoring data with recordings of individual species to reveal a pervasive loss of acoustic diversity and intensity of soundscapes across both continents over the past 25 years, driven by changes in species richness and abundance. These results suggest that one of the fundamental pathways through which humans engage with nature is in chronic decline, with potentially widespread implications for human health and well-being.
Assuntos
Acústica , Aves/fisiologia , Vocalização Animal/fisiologia , Animais , Biodiversidade , Aves/classificação , Conservação dos Recursos Naturais , Europa (Continente) , Humanos , América do Norte , Dinâmica Populacional , Estações do Ano , Som , Vocalização Animal/classificaçãoRESUMO
We compare three similar but different biological effects: provocation-neutralisation treatment of non-antibody-mediated hypersensitivities, hormesis and low-level effects in radiation biology. All three have not yet been fully explained but share some common and interesting properties: non-linear concentration dependence, typical stress pattern and typical immune response. We try to make a generalisation of the three phenomena in terms of the informational properties of the low concentrations, and imply the possible common mechanism.