Male-male fighting behavior of the seed bug, Togo hemipterus

Male-male fighting of northern elephant seals

Male-male agonistic behavior of Carrhotus xanthogramma

The re-invasion behavior of Japanese scorpionfly males that lost the male-male competition

Male-male fighting of Harbor seals 1

Male-male fighting of Harbor seals 2

Male-male agonistic behavior of Sitticus penicillatus (2)

Male-male agonistic behavior of Sitticus penicillatus (3)

Male-male agonistic behavior of Sitticus penicillatus (1)

Female-female fighting behavior of the Japanese horned beetle

Male-male competition of Japanese scorpionfly

Male-male fighting in a butterfly

Male-male competition in Uca arcuata

Agonistic behavior in Pugettia quadridens quadridens

Tinbergen's Experiment - Key stimulus releasing fighting behavior of three-spined stickleback Gasterosteus aculeatus

Nest visiting behavior of male staghorn damselfish

Courtship behavior of a male Bengalese finch

Mating behavior and male gathering of the white tailed zygaenid moths

Undirected song behavior of a male Bengalese finch

Courtship display of male guppy

Male-male sexual behavior in Cobitis magnostriata

Sneaking of male guppy

Male-male combat of Otton frogs

Fighting behavior of three-spined stickleback Gasterosteus aculeatus released by its reflected image in a mirror

Territorial contest in male Chrysozephyrus smaragdinus