“This bull and donkey show interspecies homosexual bonds can run deep”

Key points

• Ecologists André Beirão da Cruz and Martina Francesconi observed Achille the bull and Patroclo the donkey during fieldwork in Ethiopia.
• Over four days together, the pair mounted 51 times during the four days they were observed.
• The researchers describe a strong social bond, including licking and rubbing after sexual interactions.
• Experts note the behavior may be more common than reported, but domestication may limit generalizability.
• The study, published in Current Biology, highlights the complexity of interspecies sexual behavior.