Variability of little blue penguin (Eudyptula minor) diving behaviour across New Zealand

Abstract

Foraging strategies of penguin species can vary according to the quality of the marine environment, and this influences their abundance and breeding success. Little blue penguins (Eudyptula minor) are considered a candidate species for assessing near-shore marine productivity due to their usually limited foraging ranges and reliance on local resources, particularly while rearing chicks. Understanding the variability of little blue penguins diving behaviours will inform whether the species can be used as an environmental monitor. This research investigates diving behaviours and feather stable isotope values (as indicators of diet) of little blue penguins from Motuara Island, Marlborough Sounds, New Zealand, and compares them with little blue penguins from three other locations distributed across the country. The diving behaviour of little blue penguins, including dive depth and duration, were highly variable indicating that little blue penguins are an environmentally adaptable species. Because of the highly variable marine environments they inhabit, the use of little blue penguins as local monitors of New Zealand's changing marine environment requires an understanding of area and population specific diving and foraging behaviour.

Intra- and inter-individual changes in little penguin diving and isotopic composition over the breeding season

“…In particular, this variability is likely to be at the core of the bi-modal foraging strategy (short vs. long trips) adopted by little penguins in post guard that target different areas and/or prey during longer trips (Saraux et al 2011b). This could also translate to plastic response of little penguin facing a highly fluctuating environment (Chilvers 2019). This variability may therefore blur the link with isotopic composition, as the long integration period of the stable isotope measures means that we always look at a combination of short and long trips.…”

Application of fermented bran and probiotics to enhance mass-scale production of Phronima sp. in the pond

“…Amphipoda is a vital link between primary producers and higher trophic levels, like fish and marine shrimp, in aquatic ecosystems. This is relevant to the feeding habits of amphipods, which act as detritivores and waste decomposers [17,18]. Therefore, waste in ponds or unconsumed fish feed can be decomposed by Phronima sp.…”