The Ross seal is Antarctica's most mysterious, siren-singing, and elusive pack ice inhabitant.

Nature · Published 20 October 2026 · Updated 21 October 2026 Swipe more like this →

In short: Hidden deep within the densest Antarctic pack ice, the Ross seal remains the least understood of all southern pinnipeds. With disproportionately massive eyes and a repertoire of haunting, siren-like vocalizations performed entirely with a closed mouth, this solitary creature continues to evade both predators and the scrutiny of modern science.

First described during the 1841 Ross expedition, the Ross seal (Ommatophoca rossii) is a true seal that lives in near-total isolation. Unlike its more social relatives—the crabeater, leopard, and Weddell seals—the Ross seal is rarely seen, typically inhabiting the thickest, most inaccessible pack ice in solitary fashion. Its physical adaptations are striking: it possesses a short, broad muzzle and eyes reaching up to 7 cm in diameter, which likely assist in hunting squid and fish in the dimly lit depths of the pelagic zone.

Perhaps its most peculiar trait is its vocal behavior. The seal produces complex, trilling, and siren-like sounds that carry for long distances underwater. Uniquely, these vocalizations are emitted without opening its mouth or releasing air. While the exact function of these calls remains a mystery, researchers suspect they play a role in navigating the vast, empty pack ice or facilitating encounters between individuals. Despite their elusive nature, genetic surveys suggest the species has not suffered a recent, sustained population bottleneck, indicating a stable, if hidden, existence.

Life for a Ross seal is dictated by the Antarctic seasons. Females give birth on the ice in November, nursing their pups for a brief four-week period before weaning. While they are presumed to be preyed upon by killer whales and leopard seals, there are no documented observations of such events. With a total population estimated at roughly 130,000 individuals—though estimates range widely from 20,000 to 227,000—this species remains a ghost of the southern ocean, resiliently adapted to an environment that few other animals can endure.

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