Un Vínculo Inusual en la Fauna
Recent research featured in Current Biology has uncovered a remarkable sociosexual bond between a bull and a donkey, both of whom are male. While homosexual behaviour in the animal kingdom is well-documented, this particular case stands out as it involves individuals from different taxonomic families. The bull, named “Achilles,” and the donkey, dubbed “Patroclus,” reside in a grazing area in Ethiopia. Their interactions take place during daylight hours, as they belong to different owners and spend their nights apart. The research team stumbled upon this unique pairing while conducting fieldwork focused on gelada baboons.
During their observations, scientists noted that Achilles would mount Patroclus without the latter exhibiting any signs of avoidance or distress. The researchers recorded that the pair frequently engaged in affiliative behaviours—social interactions that can express or strengthen their bond, such as grooming and rubbing against one another. They also discovered that Achilles and Patroclus spent significantly more time in close proximity compared to being apart, indicating a preference for each other’s company over other animals in their herd.
Comportamientos y Observaciones Reveladoras
Remarkably, this sociosexual bond persisted even in the presence of potential female partners from both species. Observations revealed that Patroclus often presented his rear towards Achilles, while Achilles attempted to mount another male donkey on two occasions, only to be met with clear signs of avoidance and aggression.
Over a four-day observation period, researchers recorded a total of 51 instances of mounting by Achilles on Patroclus, with penetration occurring in 34 of those instances. One of the most striking findings emerged after these mounting episodes: the level of affiliative contact significantly increased following the interactions. Prior to the mounts, such behaviours were noted in approximately a quarter of the cases, but afterwards, they rose to nearly three-quarters. This suggests a potential link between sexual interactions and the maintenance of their social bond.
While interpreting this behaviour poses challenges, the authors of the study suggest that the mounting attempts, along with repeated mutual affiliative interactions, may reflect the quality of their relationship.
La Sexualidad Entre Especies: Un Fenómeno Común
Sexual behaviour among same-sex individuals is prevalent across the animal kingdom, with instances documented in a variety of species, including bonobos, bottlenose dolphins, Japanese macaques, and American bison. A 2023 study identified such behaviours in at least 261 mammalian species, proposing that these interactions may play a role in maintaining social relationships and resolving conflicts.
Moreover, sexual interactions between different species are not unheard of. For instance, in Japan, sexual behaviours of Japanese macaques towards sika deer have been recorded. Similarly, researchers on Marion Island in the sub-Antarctic observed Antarctic fur seals attempting to copulate with king penguins, although these cases were classified as “sexual harassment.”
What truly distinguishes Achilles and Patroclus’s case is that their mounting occurred within a context characterised by constant proximity, mutual preference, and affiliative behaviours, devoid of the rejection or aggression often noted in other encounters.