Gentoo penguins are one of the most ecologically flexible penguin species, but their colonies in the Falkland Islands and Antarctic Peninsula face pressures from tourism and prey change.
Gentoo penguin colonies disturbed during breeding show elevated stress hormones, nest abandonment, and reduced chick survival. Tourist approach distances that seem comfortable to observers may still trigger stress responses measurable physiologically. Krill and fish availability directly determines whether parents can feed chicks adequately - reduced prey requires longer foraging trips that leave chicks exposed to weather and predators. Tourism management that maintains appropriate distances and limits visitor numbers is welfare-protective at the colony level.