A couple of black-tailed gulls choking as a courtship behavior

Courtship feeding in a couple of black-tailed gulls

Black-tailed gulls mating

Black-tailed gulls, collecting nesting materials

Threatening behavior of a black-tailed gull toward a grey heron

Black-tailed gulls flocking around the colony

Black-tailed gulls, catching and eating adult chironomids

Long-call of black-tailed gull

A black-tailed gull, eating a dead crucian carp

Bathing Black-tailed Gulls

A black-tailed gull eating a baby red-eared slider

Greeting ceremony of black-tailed gull

Duet of long calls in black-tailed gull

Courtship behavior of a male Bengalese finch

Courtship behavior of Smews

Pecking of black-tailed gull: Dummy experiment 1

Pecking of black-tailed gull: Dummy experiment ３

Pecking of black-tailed gull: Dummy experiment 2

Pecking of black-tailed gull: Dummy experiment ４

Courtship behavior of Waved Albatross

Courtship behavior of the Common Moorhen

Courtship and spawning behavior of bluegill

A change of courtship waving display and pair formation in a fiddler crab

Courtship behavior of the spider, Cyclosa octotuberculata

Courtship and mating behavior of Bengalese finch