Larus atlanticus
Olrog's Gull (*Larus atlanticus*) is a striking medium-sized gull endemic to the South Atlantic coast of South America, known for its distinctive dark plumage and specialized feeding habits. Adults measure approximately 48-52 cm in length with a wingspan of 120-130 cm and weigh between 700-900g. Its most distinctive field mark is a deep red bill adorned with a prominent black subterminal band, coupled with yellow legs and a dark slate-gray mantle. In breeding plumage, the head is pristine whi...
Coastal environments, including sandy beaches, rocky shores, estuaries, and mussel beds, primarily at sea level.
Primarily bivalves (especially mussels), but also fish, crustaceans, marine worms, and carrion, obtained through plucking, shallow diving, and shell-dropping.
Olrog's Gulls are diurnal, often roosting in large, mixed-species flocks on beaches, sandbars, or isolated coastal islands. Their foraging behavior is highly specialized, frequently involving dropping bivalves, particularly mussels, onto hard surfaces like rocks or pavements from height to crack ...
Olrog's Gull is primarily endemic to the Atlantic coast of Argentina, where it both breeds and winters. Its breeding range extends from Buenos Aires Province southwards, with major colonies found in regions like Bahía Blanca and throughout coastal Patagonia, particularly in Chubut and Río Negro p...
Vulnerable
- Olrog's Gull is named after the Swedish-Argentine ornithologist Constantin C. Olrog, who made significant contributions to South American ornithology. - It is one of the few gull species globally that routinely uses a 'tool-dropping' technique, lifting mussels into the air and dropping them ont...