Patterns of nest attendance during the breeding season of the Little Penguin (Eudyptula minor) : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Zoology at Massey University, Manawatū, New Zealand

Abstract

Understanding the breeding behaviour of Little Penguins is essential to gauge reproductive success. This study is the first to examine Little Penguins from Port Tarakohe in the Tasman District of New Zealand, focusing on colony attendance during the 2022 breeding season. Daily nestbox monitoring was utilised for the first time in New Zealand to investigate nest attendance and breeding stages of the Little Penguin. The first analytical chapter is a colony-level investigation, identifying patterns and cycles of nestbox attendance in various categories, including males and females, breeding pairs, and breeding and non-breeding birds. The lunar cycle is also examined as a potential influence on attendance behaviour. The second analytical chapter assesses the nestbox attendance of individual breeding pairs within the Port Tarakohe colony, as the breeding season progresses through its stages. Observations from the first chapter include that pairs of Little Penguins synchronised their colony attendance over multiple months of the breeding season, corresponding to the stages of courtship, incubation and guard. Courtship and egg-laying were found to occur approximately four weeks apart, in multiple distinct waves. Male and female members of separate breeding pairs were found to synchronise their nestbox attendance during the incubation and guard phases. The nestbox attendance of non-breeding birds was found to vary cyclically over a four-week period and appeared to increase close to the time of the full moon although this was not significant. The second chapter reveals that average incubation period and guard period lengths are consistent with those reported from other colonies. Mean nestbox attendance during the incubation periods of breeding pairs was observed to be equal between different sexes. Incubation spell length was observed to rise and fall predictably over the incubation periods of different breeding pairs. One-chick clutches were observed to be guarded for longer than two-chick clutches. These findings complement, contrast with, and extend previous observations on colony attendance made at other Little Penguin colonies, and serve as a base for future research on the Port Tarakohe colony.