CIE Spotlight: Variability in the foraging range of Eudyptula minor across breeding sites in central New Zealand

Pic by JJ Harrison

Authors: Poupart, Timothee A.; Waugh, Susan M.; Bost, Caroline; Bost, Charles-Andre; Dennis, Todd; Lane, Reuben; Rogers, Karyne; Sugishita, Junichi; Taylor, Graeme A.; Wilson, Kerry-Jayne; Zhang, Jingjing; Arnould, John P. Y.

Source: NEW ZEALAND JOURNAL OF ZOOLOGY, 44 (3):225-244, 2017

Brief summary of the paper: The little penguin Eudyptula minor is primarily an inshore forager with its range generally limited to c. 30 km of breeding sites during the nesting period. However, exceptions with greater foraging distances have been recorded in Australia.

To investigate the foraging range plasticity in New Zealand we used GPS tracks gathered on 68 individuals in three regions of central New Zealand between 2011 and 2016. Foraging patterns varied between sites and between years. Tracks revealed that penguins can rely on distant foraging areas while incubating, with nesting birds travelling up to 214 km to feed.

Isotope analyses of blood samples showed that this distant food across deep waters (0–200 m) is likely to be squid dominated. During the chick rearing period, birds undertook a diet shift to a higher trophic level while foraging closer to their colony, and possibly near river plumes.

These findings highlight the need to consider the little penguins’ large potential foraging ranges when managing threats and changes to the environment.