A bull and a male donkey: researchers document a bond in Ethiopia
· BehindLines newsroom · Updated
Researchers at the University of Pisa have described in the journal Current Biology a relationship that the news agency UPI and the website ScienceAlert reported on 2 and 3 November: that of a bull and a male donkey, observed on a shared pasture in the Ethiopian highlands. According to ScienceAlert, it would be the first lasting sexual relationship between a bull and a male donkey to be documented; Elisabetta Palagi is nonetheless cautious about claiming an absolute first, according to the site Defector. The study covers a single pair of animals, so its conclusions are limited.
A chance discovery
According to ScienceAlert, the team led by ethologist Elisabetta Palagi was working in Ethiopia on gelada monkeys when it noticed, nearby, interactions between a bull named Achille and a male donkey named Patroclo, names inspired by the Greek heroes Achilles and Patroclus. According to UPI, the two animals belong to different owners, spend their nights apart and meet only during the daily grazing.
What the researchers recorded
The observations lasted four days when both animals were present and four days when only one was, UPI says. Over that period Achille mounted Patroclo 51 times, 34 of them with intromission according to ScienceAlert and Defector. When the bull approached another male donkey, that donkey showed avoidance, for example by flattening its ears; Patroclo never pulled away.
The two animals licked, rubbed and nuzzled each other more than they did with others, and spent most of the observed time close together. Contacts were more frequent after mounting than before; they might prolong social interaction, but their function has not been established. On one occasion, when Achille approached another donkey, Patroclo came in close and the bull turned to him. According to Palagi (ScienceAlert), both animals had access to other potential partners, of their own species and of both sexes, yet repeatedly sought each other out. Achille also showed some mounting behaviour towards cows, according to UPI.
Caution on interpretation
For Elisabetta Palagi, quoted by UPI, the data describe a "special" relationship. Her colleague Martina Francesconi, quoted by UPI, points out that what is known about sexual interactions between species is scarce, and that the literature held no recurrent, selective, voluntary and reciprocal case. According to Defector, earlier cases looked more like apparent harassment or mistaken identity. ScienceAlert notes, however, that the observations were accidental, that they concern a single pair, and that the authors themselves consider the meaning of these behaviours hard to establish: attributing human feelings to the animals should be avoided.
What next?
According to ScienceAlert, Achille and Patroclo were moved to different pastures after the study. It is not known whether the bond persists. The team hopes to return to see whether the animals reunite and to investigate whether such bonds between species are more common than believed. This documented case cannot establish how common such bonds are; it was covered in the press on 2 and 3 November.