Diet segregation between two colonies of little penguins Eudyptula minor in southeast Australia

Research reveals significant diet segregation between two colonies of little penguins, Eudyptula minor, at St Kilda and Phillip Island in southeast Australia, despite their overlapping foraging areas. While both colonies rely heavily on anchovies, those at St Kilda consume smaller anchovies from different cohorts or stocks compared to the more diverse diet at Phillip Island. Stable isotope analysis of nitrogen (δ15N) and carbon (δ13C) in blood samples confirmed differences in trophic position and prey size between the colonies, suggesting potential competition or spatial foraging differences. Surprisingly, protein levels in penguin blood remained consistent across colonies, indicating that dietary variation did not affect nutritional value. The study highlights the vulnerability of St Kilda's diet, which is dominated by anchovies, emphasizing the need for conservation efforts to ensure stable food supply for these penguins.

CHIARADIA, A., FORERO, M. G., HOBSON, K. A., SWEARER, S. E., HUME, F., RENWICK, L., & DANN, P. (2011). Diet segregation between two colonies of little penguins Eudyptula minor in southeast Australia. Austral Ecology, 37(5), 610–619. Portico. https://doi.org/10.1111/j.1442-9993.2011.02323.x