Macaroni penguins are the most numerous penguin species but face serious welfare threats from prey depletion, climate-driven prey shifts, and breeding failure in a rapidly changing Southern Ocean.
Macaroni penguins face welfare pressures that operate primarily at the energetic and nutritional level. Adults undertaking excessively long foraging trips return depleted and may be unable to adequately provision chicks, leading to chick starvation. The death of starving chicks is a welfare harm of significant scale given colony sizes. Adults themselves face exhaustion, increased predation risk during extended foraging, and poor body condition entering the moult — a vulnerable period when penguins cannot enter the water to feed. Oil spills in foraging areas cause feather fouling and ingestion toxicity. Plastic ingestion is an increasing concern. The cascading effects of krill depletion on penguin welfare illustrate how distant industrial activities have intimate welfare consequences.