male presenting to male

female presenting to male

female presenting to female

Egg care of male three-spined stickleback Gasterosteus aculeatus

Interruption of copulation by an intruding male

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

Copulation of Japanese Grass Lizards, interrupted by another male

Male-male combat of Otton frogs

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

Male-male combat of Otton frogs II

Egg-predation defense by the deception of a male three-spined stickleback Gasterosteus aculeatus

Male-male sexual behavior in Cobitis magnostriata

Approach with stalking by the male to the female in Microvelia horvathi Lundblad, 1933

ヤマアカガエル包接オスによる他オスの排除

Female cat solicits male

The responses of the male of Cobitis magnostriata to the vibrating finger

Suffering of a small male

Unhappy interaction between male and female fiddler crab: vol.2

Unhappy interaction between male and female fiddler crab: vol.1

Intrusion of cuckold male bluegill into spawning nest

Flight of a Morpho amathonte male

Interruption of courtship behavior of male three-spined stickleback Gasterosteus aculeatus

シロスジカノコハエトリ C.ogatai オスによるメス死体への求愛・交接

A male Red Ring Skirt (Hestina assimilis) tried unsuccessfully to mate with a female feeding on tree sap

Encountering when a male visited the territory of a female