Climate fluctuation effects on breeding of blue penguins (Eudyptula minor)

El Nino and La Nina climate perturbations alter sea currents and food avail ability for seabirds in many areas of the world. This changes their breedin g success and mortality. Blue penguin (Eudyptula minor) breeding success is dependent upon whether one or two clutches per season are laid, and the ha tching and fledging success of these clutches. This study uses six years of data from five blue penguin breeding colonies, three from Taiaroa Head, Ot ago Peninsula and two from Oamaru, to examine whether annual variation in b reeding success correlates with El Nino/La Nina perturbations. When La Nina conditions prevailed, penguins started breeding later, and there was a low er proportion of double breeders than in El Nino and normal years. The prob ability of a newly hatched chick surviving to fledging was also dependent o n whether large-scale climatic conditions prevailed, whereas hatching succe ss and overall breeding success (number of fledged chicks per breeding pair ) showed no correlation with climate perturbations.