Doug Gimesy / Grey-headed flying-fox (Pteropus poliocephalus) male licking female genitalia, Yarra Bend Park, Fairfield, Victoria, Australia, April.

Doug Gimesy / Grey-headed flying-fox (Pteropus poliocephalus) oral sex followed by unsuccessful mating, then female climbs away with male in pursuit, Yarra Bend Park, Fairfield, Victoria, Australia, April.

Doug Gimesy / Grey-headed flying-fox (Pteropus poliocephalus) male licking female genitalia; female is holding her pup, Yarra Bend Park, Fairfield, Victoria, Australia, April.

Doug Gimesy / Grey-headed flying-fox (Pteropus poliocephalus) male licking a female's genitalia, with female extending wings, Yarra Bend Park, Victoria, Australia, April.

Doug Gimesy / Grey-headed flying-fox (Pteropus poliocephalus) male licking female's genitalia as part of mating courtship. Another female defacating on edge of frame, Yarra Bend Park, Victoria, Australia, April.

Doug Gimesy / Grey-headed flying-fox (Pteropus poliocephalus) male involved in courtship / mating behaviour including licking female's genitalia; male grooming his own penis, bickering and female climbing away, Yar...

Doug Gimesy / Grey-headed flying-fox (Pteropus poliocephalus) male courtship / mating behaviour with female including licking her genitalia, then bickering, before male grooms his own penis, Yarra Bend Park, Victor...

Christian Ziegler / Bonobo (Pan paniscus) pair engaging in oral sex, Kokolopori Bonobo Reserve, Democratic Republic of the Congo