Concern at unexplained hoiho deaths 10 Jan, 2021 04:40 PM 2 minutes to read Yellow-eyed penguin chicks are falling ill with an unexplained pneumonia-like sickness. Photo / Supplied Otago Daily Times Concern is mounting for an already challenged species as a mysterious sickness kills yellow-eyed penguin chicks. The Wildlife Hospital Trust manager Jordana Whyte said the unexplained respiratory condition affected hoiho (yellow-eyed penguin) chicks across North Otago, Otago and the Catlins. "We don't understand how they are getting it and why it is killing them." On necropsy, it presented as a type of pneumonia. Advertisement It was cause for concern. "If it gets worse next year, for example, we'll be in huge trouble."