Sexual and intrapopulation variation in the territorial calls of the Blue Petrel (Halobaena caerulea) on Diego Ramírez Island, Chile
Year: 2026
Type: preprint
Abstract: Bioacoustics enables the non-invasive study of animal communication and has proven to be a useful tool in avian systematics and conservation. Within the order Procellariiformes, calls are particularly relevant given the nocturnal and philopatric behaviour of its members, and because females vocalize as much as males. We analysed the territorial calls of the Blue Petrel Halobaena caerulea on Diego Ramírez Island, the main breeding site of the species, aiming to characterize calls by sex and individual and to assess intrapopulation variation. From recordings of nesting individuals, we measured five acoustic parameters per element (low frequency, high frequency, delta frequency, delta time, and peak frequency), as well as the number of elements per vocalization. Females produced calls with a greater number of elements (10–18) than males (5–9). Accounting for the hierarchical structure of the data (elements nested within calls and individuals) using linear mixed models, delta time consistently differentiated the sexes; delta frequency showed only a marginal difference; and high, low, and peak frequency did not differ significantly between sexes. Coefficients of variation indicated that low frequency, high frequency, and delta frequency are the most individually conserved characters. In males, discriminant analysis correctly classified 65% of calls to their individual of origin through cross-validation, and PERMANOVA confirmed that individual identity explains 65% of the acoustic variation, supporting the existence of an individual vocal signature and of intrapopulation variation in this species.
Source: Research Square
Language: English
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W7203865664