INTERANNUAL VARIATION IN EGG NEGLECT AND INCUBATION ROUTINE OF RHINOCEROS AUKLETS CERORHINCA MONOCERATA DURING THE 1998-1999 EL NINO/LA NINA EVENTS

摘要

BLIGHT, L.K., BERTRAM, D.F., WILLIAMS, T.D. & COWEN, L. 2010. Interannual variation in egg neglect and incubation routine of Rhinoceros Anklets Cerorhinca monocerata during the 1998-1999 El Nino / La Nina events. Marine Ornithology 38: 11-15.We used artificial eggs containing miniature temperature loggers to quantify nest attendance patterns by breeding Rhinoceros Anklets Cerorhinca monocerata over two seasons. The first year coincided with a strong El Nino event and low breeding success, while the second was one of La Nina conditions and high colony-wide productivity. Logger data revealed highly variable patterns of parental nest attendance between the two years. In 1998, we recorded 0-17 periods of neglect per breeding pair (n = 7), as well as nest abandonment part way through the incubation period. In 1999, the number of periods of egg neglect ranged from 0-3 (n = 13), and no monitored nests were abandoned. As in other seabird species, more pairs (62%) exhibited neglect during the first third of incubation than during the subsequent two-thirds. The longest period an egg was left unattended was nearly 3 d (69 h): the shortest was 9 h. We conclude that incubating Rhinoceros Anklets were able to modulate nest attendance behaviour in response to changing oceanographic conditions and prey availability, likely mediated via their own body condition. We recommend use of similar egg models for future studies on avian nest attendance.