The influence of social relationship on food tolerance in wolves and dogs

Abstract

Food sharing is relatively widespread across the animal kingdom, but research into the socio-ecological factors affecting this activity has predominantly focused on primates. These studies do suggest though that food tolerance is linked to the social relationship with potential partners. Therefore, the current study aimed to assess the social factors which influence food tolerance in two canids: wolves and dogs. We presented wolves and dogs with two paradigms: dyadic tolerance tests and group carcass feedings. In the dyadic setting, the affiliative relationship with a partner was the most important factor, with a strong bond promoting more sharing in both species. In the group setting, however, rank was the primary factor determining feeding behavior. Although the dominant individuals of both species defended the carcass more than subordinates, in the dogs, the subordinates mostly stayed away from the resource and the most dominant individual monopolized the food. In the wolves, the subordinates spent as much time as dominant individuals in proximity to, and feeding from, the carcass. Furthermore, subordinate wolves were more able to use persistence strategies than the dogs were. Feeding interactions in the wolves, but not dogs, were also modulated by whether the carcass was on the ground or hanging from a tree. Overall, the social relationship with a partner is important in food distribution in wolves and dogs, but the precise effects are dependent on species and feeding context. We consider how the different socio-ecologies of the two species may be linked to these findings.Significance statementDespite the fact that food sharing is relatively widespread in the animal kingdom, the specific factors underlying whether an animal will share with a specific individual are little understood. When it comes to decisions about food sharing in wolves and dogs, friendship is the deciding factor if it is just two of you, but in a bigger group rank position decides your access to the spoils. What is more, it seems that rank positioning is even more important in dogs than wolves as dominant dogs keep the food for themselves while each wolf pack member has a chance to eat. This is the first evidence that the importance of the social relationship in food sharing is dependent on the feeding context in canids.Electronic supplementary materialThe online version of this article (doi:10.1007/s00265-017-2339-8) contains supplementary material, which is available to authorized users.

Importance of a species’ socioecology: Wolves outperform dogs in a conspecific cooperation task

“…Indeed, studies on captive pack-living wolves and dogs suggest that considering dogs a "tamer/friendlier" version of wolves is an oversimplification. Rather, dogs appear to exhibit different behavioral strategies than wolves when interacting with conspecifics: showing fewer formal signals of dominance but higher intensity of aggression (50)(51)(52), a more persistent use of avoidance and distance maintenance in managing conflicts in the feeding context (44,45), and a reduced inclination to coordinate actions in a cooperative task (present results). Taken together, such results suggest that changes in dogs' socioecology, in particular their reduced dependence on conspecific cooperation in hunting and pup-rearing, may have significantly affected their intraspecific social behavior in a number of ways, highlighting the importance of taking socioecology into account in theories about domestication (26).…”

“…Indeed, dogs tolerated each other's presence at the apparatus but they were significantly less likely than wolves to both engage in the task at the same time, most likely as a conflict-avoidance strategy over a coveted resource. This avoidance of a coveted resource in a potentially competitive context has been observed more often in dogs than wolves (44,45), suggesting that there may be different social strategies adopted by the two species to avoid/resolve conflicts. Difference in such strategies may in turn affect cooperative success, where a shared resource is the ultimate aim.…”

Food sharing and affiliation: An experimental and longitudinal study in cockatiels (Nymphicus hollandicus)

“…Food sharing is considered as a prosocial behavior, which is by definition intended to benefit one or more other individuals (Batson & Powell, ) and can be defined as the joint use of a monopolizable food source (Stevens & Gilby, ). Despite the costs for donors, which consists in giving‐up the nutritional value of the food, food sharing has been observed in numerous taxa like insects (Vahed, ), fish (Griffiths & Armstrong, ), birds (Amat, ; Arnold & Owens, ; de Kort, Emery, & Clayton, ), primates (see Jaeggi & van Schaik, for review; de Waal, ; Hauser, Chen, Chen, & Chuang, ; Feistner & Price, ), and other mammals like lions (Cooper, ), wolves (Dale, Range, Stott, Kotrschal, & Marshall‐Pescini, ), killer‐whales (Wright, Stredulinsky, Ellis, & Ford, ), or vampire bats (Carter & Wilkinson, , ; Wilkinson, ). More importantly, food sharing has been observed in very different contexts, between kin, during parent and offspring interactions for example (Feistner & McGrew, ), but also between non‐kin (Clutton‐Brock, ; Stevens & Gilby, ; Wilkinson, Carter, Bohn, & Adams, ).…”

Dominance in dogs as rated by owners corresponds to ethologically valid markers of dominance

“…In the next paragraphs we summarize the current knowledge about dominance in dogs and then we examine how scientific findings are related to the perception of dominance in the dog owning public. Although dominance hierarchies have previously been described in free-ranging dogs Cafazzo et al, 2010;Bonanni & Cafazzo, 2014), in dogs living in packs in enclosures (Range, Ritter & Viranyi, 2015;Van Der Borg et al, 2015;Dale et al, 2017), and in neutered pet dogs at a dog day care centre (Trisko & Smuts, 2015;Trisko, Smuts & Sandel, 2016), the existence and validity of linear dominance hierarchies in these animals is highly debated both by the public and some researchers, mainly because agonistic interactions are rare and contextual (Schilder, Vinke & van der Borg, 2014). Data on kennelled dogs suggest that dominance is based on submission (signalled mostly by body tail wag and low posture) rather than on aggression (Van Der Borg et al, 2015).…”