Thank you for visiting nature. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser or turn off compatibility mode in Internet Explorer. In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript. In a cooperative task involving joint action on a rope to pull a tray forward, wolves systematically outperformed dogs.
Indeed both the duration of co-action on the apparatus and the success rate of dyads composed of an expert and an inexperienced dog was higher than dyads composed of two inexperienced partners. For both dogs and wolves, cooperation was facilitated by the closeness of the affiliative bond between individuals, but opposite rank effects emerged.
Dogs further apart in rank were more successful co-operators, whereas in wolves, animals closer in rank had a higher cooperative success. The results further highlight the importance of the different socio-ecologies of wolves and dogs in understanding their behaviour. In general, whereas almost all species tested succeeded in solving the single apparatus, fewer were also able to negotiate setups in which waiting was involved chimpanzees 3 , elephants 8 , kea 10 and ravens 12 succeeded but rooks 7 and grey parrots 9 did not.
Not surprisingly, social relationships have been repeatedly shown to play a crucial role in such cooperative interactions. Indeed, the closeness of social bonds in terms of affiliative interactions exchanged as well as tolerance around a food source and rank have been shown to affect cooperative success in string-pulling tasks in ravens 6 , chimpanzees 3 , hyenas 11 , macaques 5 and wolves Differently from the previous loose-string study with pet dogs and most other species except ravens , we first tested animals in a Spontaneous condition, in which both partners were presented with the task with no prior experience of the apparatus.
Usually one dog at a time interacted with the ropes and the tray, whilst the other typically stood by, or wandered off. This avoidance of being active on the apparatus at the same time ultimately resulted in them almost never pulling the two rope ends together.
