Macaroni penguins are the most numerous penguin species but have declined by over 50% since the 1970s, with climate-driven prey shifts and competition from fisheries creating welfare challenges for breeding and foraging adults.
Macaroni penguins face welfare challenges concentrated in the breeding season when food stress is most acute. Adults fasting during incubation rely on body reserves, and if krill are not abundant immediately post-incubation, condition can deteriorate to the point of chick abandonment or adult mortality. Chicks that receive insufficient krill deliveries starve in the colony — a prolonged welfare harm on a massive scale given the colony sizes involved. Climate-driven krill redistribution means longer foraging trips during chick-rearing, increasing the energy costs of reproduction. Commercial krill fishery competition with colonies during the breeding season has direct welfare consequences.