Male-male competition of Japanese scorpionfly

Male-male competition in Uca arcuata

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

Male-male agonistic behavior of Carrhotus xanthogramma

Male-male fighting of northern elephant seals

Male-male agonistic behavior of Sitticus penicillatus (2)

Male-male agonistic behavior of Sitticus penicillatus (3)

Male-male agonistic behavior of Sitticus penicillatus (1)

Male-male fighting of Harbor seals 1

Male-male fighting of Harbor seals 2

Male-male competition for eggs in the filefish Rudarius ercodes

Male-male combat of Otton frogs

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

Male-male combat of Otton frogs II

Male competition of the field cricket

Male-male fighting in a butterfly

Territorial contest in male Chrysozephyrus smaragdinus

Major cheliped use in owner male during male-male contest of hermit crab

オイカワの雄間闘争

セボシタビラの雄間闘争

アブラボテの雄間闘争

Major cheliped use in intruder male during male-male contest of hermit crab

Female-female fighting behavior of the Japanese horned beetle

Female fighting of Dorcus rectus rectus

Display of a male phesant