Dynamics of Seasonal Movements by a Trans-Pacific Migrant, the Westland Petrel

• Published in: The Condor (Los Angeles, Calif.) Calif.), 2011-02, Vol.113 (1), p.71-79
• Main Authors: Landers, Todd J, Rayner, Matt J, Phillips, Richard A, Hauber, Mark E
• Format: Article
• Language: English
• Subjects: activity pattern; Animal migration behavior; Aquatic birds; archival data logger; Aviculture; Behavior; Birds; Breeding seasons; Coastal zone; Data processing; Foraging behavior; geolocator (GLS); Habitat conservation; Light; Loggers; Male animals; Marine; Methods; migration; Ornithology; Petrels; Procellaria westlandica; RESEARCH PAPERS; Return migration; Sea birds; seabird tracking; Software; Studies; Westland Petrel
• ISSN: 0010-5422; 1938-5129; 2732-4621
• DOI: 10.1525/cond.2011.100064

Knowledge of the dynamics of long-distance migrations of pelagic seabirds is limited. Recent advances in tracking technology have yielded detailed, continuous accounts of the movements of individual seabirds over large spatial and temporal scales. We studied the timing of migration and year-round distribution of the Westland Petrel (Procellaria westlandica), listed by the IUCN as vulnerable, with miniature archival light loggers (geolocators) deployed on 10 incubating birds breeding in 2007 at Westland, New Zealand. We retrieved data from eight Westland Petrels, indicating the birds migrated in November directly east ∼7000 km from the coast of New Zealand to South American waters in 6 days (range 4–7), then returned the following April in 10 days (range 8–13). The durations of an individual's outward and return flights and the dates of its outward and return migrations were positively correlated. During their journeys east and west, birds spent on average (±SD) 9.9% (±9.7) and 17.2% (±12.0), respectively, of their time on the water. There was also considerable variation in individuals' foraging areas: while breeding, birds used three major coastal areas