CESIMAR - CENPAT   25625
CENTRO PARA EL ESTUDIO DE SISTEMAS MARINOS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Stable isotope analysis show dietary plasticity in Fiordland penguin (tawaki)
Autor/es:
WHITE, JEFF; GARCÍA BORBOROGLU, PABLO; HOPKINS, JOHN III; ELLENBERG, URSULA; SEDDON, PHIL; MAYS, HERMAN; MATTERN, THOMAS; HOUSTON, DAVID; CROWLEY, BROOKE
Lugar:
New York
Reunión:
Congreso; North American Ornithological Congress; 2020
Institución organizadora:
American Ornithological Society
Resumen:
Fiordland penguins (or tawaki; Eudyptes pachyrhynchus) depend on the abundant resources of the Tasman Sea and Southern Ocean to fuel reproduction and sustain them through the molting fast. Tawaki occupy a broad range of marine habitat types during the breeding season, suggesting high adaptability and potentially indicate dietary plasticity. To identify differences in foraging strategies among marine habitat types (pelagic, continental shelf, or fjord), we analyzed stable isotope ratios of carbon (13C/12C, expressed as δ13C values) and nitrogen (15N/14N, expressed as δ15N values) in penguin blood and feathers over 2 and 5 year periods respectively. This allowed a comparison of dietary preferences across the breeding range during incubation and among sites during the pre-molt dispersal. We found that both δ13C and δ15N values differed significantly between tissues, suggesting the diets were different during those two periods of the annual cycle. During incubation, δ15N values were higher in the fjord than other colonies and δ13C values differed significantly between years. We found that δ13C values were significantly different between some colonies, sexes, and years during the pre-molt. δ15N values differed only between years, reflecting potential differences in diet or in marine conditions. These data indicate that tawaki do exhibit a degree of dietary plasticity depending on season and marine conditions. Unlike many penguins, tawaki appear to have a stable population. Understanding the foraging requirements of this enigmatic species will help conservationists predict how tawaki may respond to a changing ocean.