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

Male-male competition of Japanese scorpionfly

Male-male agonistic behavior of Carrhotus xanthogramma

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 behavior of the seed bug, Togo hemipterus

Male-male competition in Uca arcuata

Male-male fighting of northern elephant seals

Female-female fighting behavior of the Japanese horned beetle

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 competition of the field cricket

Sperm release behavior of the dusky frillgoby Bathygobius fuscus males

Male-male combat of Otton frogs

Male-male combat of Otton frogs II

Chasing and sneaking behavior of male Japanese bitterling

Mating behavior of the Japanese burnet moths

Mating behavior of the Japanese burnet moths

nuptial gifting behavior of the Japanese scorpionfly

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

Mating behavior and male gathering of the white tailed zygaenid moths

Mating behavior of the Japanese badger Meles anakuma

Mating behavior of the Japanese badger Meles anakuma