eWestern Birds
The Quarterly Journal of Western Field Ornithologists
Vocal Differences among the Barred, Cinereous, and Fulvous Owls
Nathan Pieplow and Andrew Spencer
ABSTRACT: The Cinereous Owl (Strix sartorii), a Mexican pine forest endemic, has long been considered a subspecies of the Barred Owl (S. varia). In this study, we provide the first description and analysis of its vocalizations, which differ markedly from those of the Barred Owl and support the recognition of the Cinereous Owl as a full species. Its rhythmic song consists of seven primary notes and three secondary notes, whereas the analogous song of the Barred Owl consists of six primary notes and two secondary notes, arranged in a different pattern. The rhythmic song of the closely related Fulvous Owl (S. fulvescens) has only five or six primary notes, versus seven in that of the Cinereous Owl. The Cinereous Owl’s song is much lower in pitch than the Fulvous Owl’s. Unlike the Fulvous Owl but like the Barred Owl, the Cinereous Owl also has a distinctive and frequently deployed series song.