Seasonal Changes in Diving and Flying Activities of Rhinoceros Auklets Cerorhinca monocerata throughout the Non-breeding Period

To understand how migratory seabirds meet the energetic challenges associated with wing molt and wintering, a full annual cycle behavioral study is needed. We studied the diving and flying activities of three Rhinoceros Auklets Cerorhinca monocerata migrating in the northwestern Pacific. The auklets decreased daily flight time and dive depth for seven weeks from the end of summer, presumably associated with primary feather molt. In winter, they increased dive depth (~81 m) and daily dive time. We suggest that Rhinoceros Auklets adjust their diving and flying behaviors in response to wing molt and energy demands in winter