A population of Gentoo penguins has been discovered on the remote Kerguelen Islands and recognized as a separate species. This marks the first time a new penguin species has been named in over a century.
The newly identified southeastern Gentoo penguin (Pygoscelis kerguelensis) inhabits the Kerguelen Islands—a remote French territory in the southern Indian Ocean, also known as the Desolation Islands. This archipelago is thousands of kilometers from permanently inhabited lands.
According to Oceanographic Magazine, this discovery resulted from international scientific research. Researchers used genetic, ecological, and physical data to resolve a long-standing debate about the number of Gentoo penguin species.
Historically, Gentoo penguins were considered a single widespread species, but scientists have now identified four distinct species within this group: northern Gentoo, southern Gentoo, eastern Gentoo, and the recently described southeastern Gentoo.
The research findings, published in Communications Biology, are based on whole-genome sequencing of penguins from breeding sites across the species' range, as well as comparisons of their morphology, vocalizations, breeding patterns, diet, and behavior.
The southeastern Gentoo is of particular interest because it outwardly resembles other Gentoo penguins. However, differences become much more apparent when studying its genetics, allowing scientists to classify it as a cryptic species.
Researchers determined that these four lineages diverged relatively recently, approximately 300,000 to 500,000 years ago. Geographic isolation, differences in the marine environment, and the penguins' tendency to remain close to nesting sites likely contributed to this divergence.
The isolation of the Kerguelen Islands may explain the long unnoticed existence of this penguin. The archipelago is located near the Antarctic Polar Front—an important boundary in the Southern Ocean where water temperature and salinity change sharply. These oceanographic features can restrict movement between penguin populations and promote their genetic separation.
The new southeastern Gentoo is associated with Kerguelen and, researchers believe, has a connection with the nearby Heard Island. Instances of young individuals traveling between these regions have been recorded.
Although the birds may not look drastically different from their Gentoo relatives, their genomes show adaptations to specific environmental conditions. The discovery also raises conservation questions.
Climate projections by researchers suggest that some Gentoo lineages inhabiting subantarctic islands may lose suitable habitats as temperatures rise. The southeastern Gentoo is among the vulnerable species because its island range is limited, leaving little room for the island endemic to migrate when conditions change.
The southern Gentoo, which lives further south in Antarctica, may face a different future: according to some climate scenarios, its suitable habitat may expand.
Climate change is not the only threat to penguins in the Southern Ocean. Rising sea temperatures, changes in food availability, the emergence of introduced predators, competition from fishing, and accidental capture in fishing gear can put pressure on isolated populations.
Researchers emphasize that recognizing different Gentoo species is crucial for conservation efforts. What was previously considered one extensive species is now understood as a collection of several geographically isolated populations, each facing different ecological challenges.
This discovery clearly demonstrates how modern genetic research can reveal biodiversity that is difficult to recognize based on appearance alone. The research team analyzed the genomes of 64 penguins from 10 colonies, representing one of the most comprehensive surveys of Gentoo penguin diversity to date.
Scientists note that the genetic information obtained can be useful not only in taxonomy but also in helping specialists study the reasons for the greater resilience of some penguin populations to threats such as disease and environmental change.