INVESTIGADORES
PEDRANA Julieta
artículos
Título:
Post-Fledging Dispersal of King Penguins (Aptenodytes patagonicus) from Two Breeding Sites in the South Atlantic
Autor/es:
PÜTZ, K., TRATHAN P.N., J. PEDRANA, M.A. COLLINS, S. PONCET, B. LÜTHI
Revista:
PLOS ONE
Editorial:
PUBLIC LIBRARY SCIENCE
Referencias:
Lugar: San Francisco; Año: 2014
ISSN:
1932-6203
Resumen:
Nearly all studies conducted so far on the foraging ecology of marine vertebrates are limited to breeding adults, although other life stages can represent up to half of the total population. In penguins, particularly little is known about the dispersal of juveniles that may be susceptible to increased mortality due to their naïve behaviour. We equipped king penguin fledglings in December 2007 with satellite transmitters both at the Falkland Islands (n = 10) and at South Georgia (n = 8) in the South Atlantic Ocean in order to monitor their behaviour whilst foraging at sea for the first time. Both breeding sites differ with respect to climate and location in relation to the Antarctic Polar Front (APF), which is a key oceanographic structure for king penguin foraging success. Accordingly, birds from both sites foraged predominantly in the vicinity of the APF. However, three penguins from the Falkland Islands migrated to the eastern coast of Tierra del Fuego before travelling south. All other observed differences were only minor and deemed to be of individual nature. Eight king penguins were tracked for periods greater than 120 days; seven of these (three from the Falkland Islands and four from South Georgia) migrated into the Pacific. Only one bird from the Falkland Islands moved into the Indian Ocean, visiting the northern limit of the winter pack-ice at least twice. Derived tracking parameters describing their migratory behaviour did not detect any significant differences between sites. However, generalized linear habitat modelling revealed that the juveniles from the Falkland Islands spent more time in comparatively shallow waters with low sea surface temperature, sea surface height and Chlorophyll variability. Birds from South Georgia spent more time in deeper waters with low sea surface temperature and sea surface height, but high concentrations of Chlorophyll. The results indicate that inexperienced king penguins, irrespective of the location of their natal site in relation to the position of the APF, develop their foraging skills progressively over time, including specific adapations to the environment around their prospective breeding site.