During the breeding season, Pigeon Guillemots (Cepphus columba) can often be heard making high-pitched vocalizations to one another. Whistles may be used by males to attract a mate, while trills are utilized between pairs. This particular bird, located on Southeast Farallon Island, had just finished trilling over a long distance to their mate.

[Photo and caption by Lindsey Broadus]

Nelson, D. A. (1984). Communication of Intentions in Agonistic Contexts By the Pigeon Guillemot, Cepphus columba. Behaviour, 88(1), 145–188. doi:10.1163/156853984X00524.

Nelson, D. A. (1985). The Syntactic and Semantic Organization of Pigeon Guillemot (Ceppbus columba) Vocal Behavior. Zeitschrift für Tierpsychologie, 67(1–4), 97–130. doi:10.1111/j.1439-0310.1985.tb01381.x.