Vocalizations and species limits in the North Atlantic clade of small shearwaters (Procellariiformes: Puffinus)

Species limits in the North Atlantic clade of small shearwaters (Pufnus lherminieri lherminieri, P. l. baroli, and P. l. boydi) have been controversial. In this study, the aerial calls of P. l. boydi are described in detail and compared with those of P. l. baroli and P. l. lherminieri. Multivariate methods were used to test for diferences in seven characteristics of aerial calls among the three taxonomic groups, in a sample of 135 individuals. Tere were diferences between males and females in fve of the seven call elements studied and diferences in all seven call elements among the three taxonomic groups. Discriminant function analysis provided a high degree of discrimination, with 91%–100% of the calls being assigned to the correct taxon. Te overall level of acoustic diferentiation between P. l. baroli and P. l. boydi was similar to that between P. l. baroli and P. l. lherminieri and twice as high as that of P. l. boydi and P. l. lherminieri. Tese acoustic data, in combination with previously reported paterns of morphometric and molecular divergence, support the recognition of three North Atlantic species: P. lherminieri, P. baroli, and P. boydi. Tis study underscores that paterns of acoustic variation provide a useful source of information for taxonomic studies of procellariiform seabirds.