Represents a robust, heavy-bodied seabird morph displaying intermediate phenotypic traits resulting from the interbreeding of two prominent subantarctic avian taxa, characterized by a massive chest, stout neck, and a powerful, hooked black bill. Overall body length spans from 53 to 60 cm, coupled with an expansive wingspan reaching between 130 and 145 cm, and an average mass ranging from 1200 to 1850 g, exhibiting physical proportions balanced between the bulky structure of the brown skua and the comparatively slender lines of the Chilean counterpart. The plumage exhibits variable coloration, presenting a dark sooty-brown crown and mantle subtly counterbalanced by warm cinnamon-rufous tones across the underwing coverts, flanks, and belly, reflecting genetic contributions from the Chilean lineage mixed with the drabber, uniform mottling of the subantarctic form. Prominent, stark bright white patches adorn the bases of the primary flight feathers, creating unmistakable flashing wing signals during flight. The sturdy, webbed feet and tarsi are pigmented deep slate-black, possessing razor-sharp curved claws adapted for capturing and pinning squirming prey items.

Geographical distribution: Inhabits the hybrid zones and overlapping maritime frontiers of southern South America, featuring verified breeding records across the rocky islets of the Beagle Channel, eastern Tierra del Fuego, coastal reaches of Santa Cruz province, and the gulf shores of southern Argentina. It is likewise detected across the coastal perimeter of the Falkland Islands (Islas Malvinas), where sympatric interactions between parent forms frequently occur. Non-breeding individuals undertake extensive pelagic migrations northward along the continental shelf waters of the Southwestern Atlantic, ranging toward northern Argentina and southern Brazil, while occasionally drifting into coastal channels along the Pacific coast of southern Chile.

Habitat: Frequents wind-swept maritime coasts, cliff tops, rocky islets, subantarctic coastal tundras, and open terraces vegetated by low maritime tussock grasses (Poa flabellata). The bird favors elevated oceanic vantage points offering uninhibited views over surrounding seabird colonies and coastal waters while conscientiously steering clear of enclosed, wooded littoral zones. During the non-breeding season, it adopts a distinctly oceanic regime, residing within the productive cold-water upwelling sectors of the Malvinas Current over the outer edge of the shallow neritic shelf.

Feeding: Functions as an opportunistic apex predator, generalist scavenger, and persistent kleptoparasite situated at the uppermost tier of the littoral marine food web. It heavily predates the eggs, chicks, and occasionally adults of colonial seabirds, particularly Magellanic penguins (Spheniscus magellanicus), rock shags, and storm-petrels. Its versatile predatory regime also comprises epipelagic fish like southern sprats (Sprattus fuegensis), marine crabs, stranded cephalopods, and discarded offal trailing commercial bottom-trawling vessels, which are followed relentlessly across offshore waters.

Behavior: Displays a solitary or pair-bonded social structure underpinned by an exceptionally combative, hyper-territorial demeanor when defending coastal home ranges. It is well known for acrobatic aerial pursuit routines directed against gulls, terms, and small shearwaters, harassing target birds with persistent dives until forced regurgitation occurs. On the ground, it walks with an erect posture and frequently vocalizes with harsh, penetrating barks while performing vertical wing-raising threat displays. Intruders, including large mammals and researchers venturing close to nesting territories, are met with violent, precision dive-bombing strikes.

Nesting: Establishes its nest site upon open coastal ground, creating a shallow scrape directly into bare soil, weathered gravel, or trampled vegetation mats, occasionally lining the saucer with small scraps of withered grass, lichens, and feathers. The egg-laying event transpires between November and December, yielding a clutch of one to two eggs exhibiting an effective protective camouflage of olive-buff mottled with deep chocolate blotches. Both parent skuas vigorously defend the nest radius and partake in steady incubation duties lasting between 28 and 32 days. The semi-precocial young hatch clad in dense down and disperse into nearby vegetative shelter within days, reaching full fledge status approximately 40 to 50 days following hatching.

Conservation status: Lacks a formal taxonomic conservation rank under the red list categories defined by the International Union for Conservation of Nature (IUCN), owing to its status as a recognized hybrid taxon formed by Catharacta chilensis and Catharacta antarctica (both taxa currently categorized as Least Concern). Local populations are nevertheless susceptible to cumulative environmental stresses, including localized disruptions in marine prey biomass driven by industrial overfishing, chemical contaminants, and long-term oceanic warming trends across subantarctic latitudes.