A long-term study of the king penguin colony on Île aux Cochons, situated in the southern Indian Ocean, has documented a dramatic decline in population. Once considered the largest king penguin colony in the world, the site has seen its numbers drop by nearly two-thirds over the past 14 years. Scientists analyzing satellite imagery and helicopter surveys found that the population, which previously numbered in the hundreds of thousands, has shrunk significantly since the last comprehensive survey in 2006.

Researchers suggest that climate change is a major factor contributing to this decline. The environmental shifts in the region are believed to have disrupted the penguins' access to food sources and impacted their breeding success. While the study highlights the severity of the population loss, the remote nature of the island makes ongoing monitoring difficult, leading to questions about whether the colony can recover or if this trend is indicative of broader ecological changes affecting the species across the sub-Antarctic region. The study emphasizes that while other colonies in the area have remained stable, the specific conditions on Île aux Cochons have created a unique and concerning trajectory for this specific group of birds.