Table 2.

Ecological traits and dietary specializations evaluated as possible factors associated with risk of undergoing declines among marine birds

Foraging strategy
Diving	Surface diving—pursuing prey while swimming underwater using either wings or feet
Surface seizing	Includes picking up prey from the surface and surface plunging
Dabbling	Submerging head and neck or tipping headfirst into water while searching for food
Intertidal wading	Includes beach probing, rock gleaning, intertidal wading, and ambushing
Scavenging	Takes a variety of items including refuse or carrion
Dietary specialization
Forage fish species	Includes herring, sandlance, smelt anchovies, and other schooling species
Demersal fish species	Includes bottom dwelling fishes such as flounders, sculpins, sticklebacks, and gunnels
Fish roe	Typically herring or salmon roe
Snails	Snails limpets and their kin
Bivalves	Mussels and clams
Crustaceans	Krill, crayfish, and crabs
Mammals or birds	Marine mammals, bird chicks, and eggs
Plant material	Plants, seeds, algae, and vegetation
Breeding
Local versus nonlocal breeders