Are environmental factors responsible for changed breeding behaviour in emperor penguins? - Paranhos Zitterbart, Daniel; Richter, Sebastian; Spiekermann, Georg; Behrens, Lisa K.; Regnery, Julia; Fontes, Renè P.; Hänssler, Thedda; König-Langlo, Gert; Weller, Rolf; Fabry, Ben (Antarctic Science, 2014)