Unusual stability of diet of the New Zealand fur seal (Arctocephalus forsteri) at Banks Peninsula, New Zealand

Abstract

The diet of the New Zealand fur seal Arctocephalus forsteri was determined from examination of scats and regurgitates collected from two breeding colonies at Banks Peninsula, Canterbury. Identifiable otoliths and squid beaks were obtained from 392 scats and 16 regurgitations collected over four seasons in 2008. Nine species were identified in scats and three species were identified in regurgitates. Arrow squid (Nototodarus sloanii) accounted for the greatest proportion of biomass taken (>90%), followed by lanternfish (Lampanyctodes hectoris and Symbolophorus sp.; 4%) and barracouta (Thyrsites atun; 2.6%). Although slight differences in diet were detected spatially and temporally, both colonies had a squid-dominated diet year round. This differs from the seasonal dietary variation shown in other areas around mainland New Zealand. © 2012 Copyright The Royal Society of New Zealand.