Marine Birds Feed at Gray Whale Mud Plumes in the Bering Sea

• Published in: The Auk
• Main Authors: Obst, Bryan S., Hunt, George L.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Oxford Univ. Press 1990
• Subjects: Bering Sea; Fulmar; Fulmarus glacialis; Northern Fulmar; Red Phalarope; rissa tridactyla; thick-billed murre; Uria lomvia; uria
• Online Access: https://oceanrep.geomar.de/id/eprint/36597/; https://oceanrep.geomar.de/id/eprint/36597/1/2115.pdf; https://doi.org/10.2307/4087998

Gray whales (Eschrichtius robustus) feeding in the northern Bering Sea produce prey-rich mud plumes that provide ephemeral foraging opportunities for seabirds. Approximately 67% of all gray whales were attended by birds. In four whale-associating bird species (Northern Fulmar, Fulmarus glacialis; Red Phalarope, Phalaropus fulicaria; Black-legged Kitti-wake, Rissa tridactyla; and Thick-billed Murre, Uria lomvia), from 17 to 87% of all individuals that we observed on the water or foraging were in the whales' mud plumes. The combined density of these same four species was strongly correlated with whale density over a broad range of spatial scales. The whale-associating seabirds exhibited species-specific patterns of foraging behavior at plumes, including differences in mean group size, mean residence time, and patterns of movement between plumes. Birds tended to form larger groups and to form more mixed-species flocks in association with whales. The association of marine birds with gray whales in the Bering Sea provides a model system for examining seabird interactions at fine-scale oceanographic patches and demonstrates the importance of these patches in shaping patterns of seabird distribution and behavior.