Haiyan, a type of seabird roughly the size of a bird of prey or a swallow.
They often fly in flocks at low altitude over the sea during storms, as the low pressure before a heavy rain makes fish surface, which creates this scene as the Haiyan hunts for food. Because of this, people romantically believe that this animal prefers extreme weather like storms.
The famous literary figure, proletarian writer Maxim Gorky, depicted such scenes in "The Song of the Stormy Petrel." The phrase 'Let the storm be stronger' became a widely-known saying.
