Analisi dei pattern di vocalizzazioni notturne primaverili degli uccelli in un sito Piemontese

Birds emit vocalisations both at day and night to delimit their reproductive territory and during migration. These calls and songs can be recorded by passive acoustic monitoring tools and can provide information on several biological phenomena, like the intensity of migration as an estimate of the number of individuals and species and their territorial singing activity. The latter may be affected by anthropogenic disturbance such as night lighting in the urban environment – ALAN, altering the photoperiod. The purpose of this work was to describe the singing activity of the species present in a small town named Vogogna (VB) and to evaluate their soundscape using bioacoustic indices. The recordings were analysed with dedicated software and then the vocalising species were identified. The acoustic indices ACI and ADI were calculated based on the nocturnal recording sessions of April 2021. The relationships between the individual acoustic episodes and the acoustic indices were established using statistical analysis software. Overall, over 4650 nocturnal vocalisations belonging to 59 different bird species have been selected. The results demonstrate a correlation between the number of vocalisations and the value of the acoustic indices, confirming the importance of these parameters in the analysis of the soundscape. Through the study of the songs and calls of the individual species it is possible to analyse the occupancy patterns during a certain period. Although some difficulties remain in the automatic recognition of species, passive acoustic monitoring offers the opportunity to carry out extensive studies over time with limited cost, while their applications are constantly growing.