Pair-bonding and companion recognition in domestic donkeys, Equus asinus

Donkeys like to be with a friend

Source: L.M.A. Murray, K. Byrne, R.B. D’Eath
Applied Animal Behaviour Science, vol 143 no 1, January 15 2013, pp 67-74.

Pair bonding is common when animals are kin, or courting, and this has been studied a lot, but there has been less work on social pair bonding between unrelated animals with no sexual motivation. It is easier for such bonds to develop when animals recognize their companions. This study aimed to investigate social pair bonding in unrelated domestic donkeys, and to see whether the donkeys could recognize their companions in a recognition test involving a Y maze.

The study involved 55 donkeys at the Scottish Borders Donkey Sanctuary, some of which had arrived with a companion, and they and their companion were kept together. Others had arrived alone. Many had been family pets. There were 38 gelded males and 17 females kept in seven groups, either same sex or mixed, each group comprising from 4 to 14 individuals. Observations on each donkey’s nearest neighbour were made three times daily for 22-days. Forty two of the donkeys, or 79.2 %, showed a preference for being with another individual donkey, and the relationships were mostly reciprocal. Twenty-four (12 pairs) of these 42 donkeys then took part in a Y-maze recognition test, where they had to choose between being with their usual companion, and a donkey they were familiar with from the same group, or a donkey they were not familiar with from another group. Where the donkeys stood indicated that they preferred being with their companion rather than a familiar donkey.

Some donkeys that did not bond with another had only recently arrived, so may not have had time to develop a friendship. Other loners had spent a long time at the sanctuary, and previous friendships may have been disrupted by new arrivals, though these donkeys may have just preferred to be alone, or not found a companion they got on with. This study backs accounts by donkey-handlers of pair bonds between donkeys, which are based on reciprocal social preference and the ability to recognize companions. These findings are important for people caring for donkeys, because keeping pairs together is good for their physical and psychological welfare.
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