Observation of female-male mounting in the carrion crow

In the biological sciences, sexual behaviours in non-human animals are traditionally investigated in the context  of reproduction and direct fitness benefits. While the evolutionary functions of non-conceptive sexual behaviours  (‘socio-sexual behaviours’) remain less well explored, these interactions and displays have been suggested to be  important for shaping and maintaining social relationships. Here, we report an observation of a captive female  carrion crow, Corvus corone corone, mounting her co-housed male partner. We highlight the importance of more  systematic research, reporting, and discussions of rarely observed behaviours in social evolution research,  including considerations for behaviours that transcend binary or heteronormative frameworks, for a more  comprehensive understanding of non-conceptive socio-sexual behaviours.