Dogs and wolves do not differ in their inhibitory control abilities in a non-social test battery.

Being able to inhibit certain behaviours is of clear advantage in various situations. In particular, it has been suggested that inhibitory control plays a role in problem-solving and cooperation. Interspecific differences in the capacity for inhibitory control have been attributed to social and ecological factors, while one additional factor, namely domestication, has received only little attention so far. Dogs are an interesting species to test the effects of socio-ecological factors and also the influence of domestication on inhibitory control abilities. While dogs might have been selected for enhanced inhibition skills during domestication, the predictions derived from their socio-ecological background are reversed. Wolves are cooperative hunters and breeders, while dogs predominately scavenge and raise their young alone, accordingly, it would be predicted that dogs show impaired inhibitory control abilities since they no longer rely on these coordinated actions. To test these hypotheses, we assessed inhibitory control abilities in dogs and wolves raised and kept under similar conditions. Moreover, considering the problem of context-specificity in inhibitory control measures, we employed a multiple-test-approach. In line with previous studies, we found that the single inhibition tests did not correlate with each other. Using an exploratory approach, we found three components that explained the variation of behaviours across tests: motivation, flexibility, and perseveration. Interestingly, these inhibition components did not differ between dogs and wolves, which contradicts the predictions based on their socio-ecological backgrounds but also suggests that at least in tasks with minimal human influence, domestication did not affect dogs' inhibitory control abilities, thus raising questions in regard to the selection processes that might have affected inhibitory control abilities during the course of domestication.

In-group defense, out-group aggression, and coordination failures in intergroup conflict.

Intergroup conflict persists when and because individuals make costly contributions to their group's fighting capacity, but how groups organize contributions into effective collective action remains poorly understood. Here we distinguish between contributions aimed at subordinating out-groups (out-group aggression) from those aimed at defending the in-group against possible out-group aggression (in-group defense). We conducted two experiments in which three-person aggressor groups confronted three-person defender groups in a multiround contest game (n = 276; 92 aggressor-defender contests). Individuals received an endowment from which they could contribute to their group's fighting capacity. Contributions were always wasted, but when the aggressor group's fighting capacity exceeded that of the defender group, the aggressor group acquired the defender group's remaining resources (otherwise, individuals on both sides were left with the remainders of their endowment). In-group defense appeared stronger and better coordinated than out-group aggression, and defender groups survived roughly 70% of the attacks. This low success rate for aggressor groups mirrored that of group-hunting predators such as wolves and chimpanzees (n = 1,382 cases), hostile takeovers in industry (n = 1,637 cases), and interstate conflicts (n = 2,586). Furthermore, whereas peer punishment increased out-group aggression more than in-group defense without affecting success rates (Exp. 1), sequential (vs. simultaneous) decision-making increased coordination of collective action for out-group aggression, doubling the aggressor's success rate (Exp. 2). The relatively high success rate of in-group defense suggests evolutionary and cultural pressures may have favored capacities for cooperation and coordination when the group goal is to defend, rather than to expand, dominate, and exploit.

A new approach to understanding canine social cognition.

Domestic dogs have become well known for their socio-cognitive successes, so what does it mean when domestic dogs fail to cooperate? A new study by Marshall-Pescini, Schwarz, Kostelnik, Virányi, and Range (PNAS, 114(44) 11793-11798, 2017) highlights the importance of considering socioecological context, learning, and relationship quality when evaluating the social cognition of dogs and wolves.

Cross-jurisdictional management of a trophy-hunted species.

Gray wolves (Canis lupus) are managed for competing uses in the Greater Yellowstone Ecosystem (GYE). Tourism benefits Yellowstone National Park (YNP) visitors while trophy hunting benefits hunters outside of the park. We investigate the policy scope of gray wolf management across jurisdictional boundaries by incorporating three foundations of the behavioral ecology of wolves: refuge-seeking behavior, optimal foraging group size and territoriality. Tradeoffs between and within consumptive and non-consumptive human benefits and wolf population fitness and life history indicators are quantified as a set of elasticities, providing clear implications to resource managers. Our approach highlights that hunting intensity affects the provision of consumptive and non-consumptive human benefits across jurisdictional boundaries and ought to be managed accordingly. We also show that population levels are an incomplete indicator of species fitness, which may depend on how hunting policies impact underlying group ecology. Our findings suggest traditional optimization approaches to wildlife management may lead to suboptimal policy recommendations when the boundaries on the natural system are oversimplified. Highlighting the human element of wildlife management, we show that understanding tourist and hunter responses to wildlife population abundances is critical to balancing provision of consumptive and non-consumptive human uses.

Testing the myth: tolerant dogs and aggressive wolves.

Cooperation is thought to be highly dependent on tolerance. For example, it has been suggested that dog-human cooperation has been enabled by selecting dogs for increased tolerance and reduced aggression during the course of domestication ('emotional reactivity hypothesis'). However, based on observations of social interactions among members of captive packs, a few dog-wolf comparisons found contradictory results. In this study, we compared intraspecies aggression and tolerance of dogs and wolves raised and kept under identical conditions by investigating their agonistic behaviours and cofeeding during pair-wise food competition tests, a situation that has been directly linked to cooperation. We found that in wolves, dominant and subordinate members of the dyads monopolized the food and showed agonistic behaviours to a similar extent, whereas in dogs these behaviours were privileges of the high-ranking individuals. The fact that subordinate dogs rarely challenged their higher-ranking partners suggests a steeper dominance hierarchy in dogs than in wolves. Finally, wolves as well as dogs showed only rare and weak aggression towards each other. Therefore, we suggest that wolves are sufficiently tolerant to enable wolf-wolf cooperation, which in turn might have been the basis for the evolution of dog-human cooperation (canine cooperation hypothesis).

When dogs look back: inhibition of independent problem-solving behaviour in domestic dogs (Canis lupus familiaris) compared with wolves (Canis lupus).

Domestic dogs have been recognized for their social sensitivity and aptitude in human-guided tasks. For example, prior studies have demonstrated that dogs look to humans when confronted with an unsolvable task; an action often interpreted as soliciting necessary help. Conversely, wolves persist on such tasks. While dogs' 'looking back' behaviour has been used as an example of socio-cognitive advancement, an alternative explanation is that pet dogs show less persistence on independent tasks more generally. In this study, pet dogs, shelter dogs and wolves were given up to three opportunities to open a solvable puzzle box: when subjects were with a neutral human caretaker, alone and when encouraged by the human. Wolves were more persistent and more successful on this task than dogs, with 80% average success rate for wolves versus a 5% average success rate for dogs in both the human-in and alone conditions. Dogs showed increased contact with the puzzle box during the encouragement condition, but only a moderate increase in problem-solving success. Social sensitivity appears to play an important role in pet and shelter dogs' willingness to engage in problem-solving behaviour, which could suggest generalized dependence on, or deference to, human action.

Being a victim or an aggressor: Different functions of triadic post-conflict interactions in wolves (Canis lupus lupus).

Animals adopt different behavioral strategies to cope with the conflict of interests coming from the competition over limited resources. Starting from the study on chimpanzees, post-conflict third-party affiliation (the affiliative contact provided by a third-party toward the victim--VTA--or the aggressor--ATA) was investigated mainly in primates. Later, this post-conflict mechanism has been demonstrated also in other mammals, such as wallabies, horses, dolphins, domestic dogs, and wolves. Here, we present data on triadic post-conflict affiliation in wolves (Canis lupus lupus) by exploring some of the hypotheses already proposed for primates and never tested before in other social mammals. In this carnivore species, the study of VTA and ATA revealed that these strategies cannot be considered as a unique behavioral category since they differ in many functional aspects. VTA serves to protect the victim by reducing the likelihood of reiterated attacks from the previous aggressor and to reinforce the relationship shared by the third-party and the victim. On the other hand, ATA has a role in bystander protection by limiting the renewed attacks of the previous aggressor toward uninvolved group-members (potential third-parties). In conclusion, exploring VTA and ATA gives the opportunity to concurrently demonstrate some functional differences in triadic post-conflict affiliation according to the different targets of bystanders (victims or aggressors). The data comparison between primates and other social mammals should permit to open new lines of research.

A method to assess relative preference for training and environmental enrichment in captive wolves (Canis lupus and Canis lupus arctos).

It is currently debated as to whether or not positive reinforcement training is enriching to captive animals. Although both husbandry training and environmental enrichment (EE) have been found to benefit animal welfare in captivity, to date, no systematic investigation has compared an animal's preference for performing a trained behavior to engaging freely with a stimuli provided as EE. In the current paper, we used four captive wolves to (1) test the efficacy of a paired-stimulus preference assessment to determine preference for engaging in a trained behavior as a choice; and to (2) use a paired-stimulus preference assessment to determine whether or not individuals prefer to engage in a previously trained behavior versus a previously encountered EE stimuli. Of the four subjects tested, visual inspection of the graphs revealed that two of the subjects preferred trained behavior stimuli and two of the subjects preferred EE stimuli; only one of the wolves had a statically higher preference for an EE stimulus over a trained behavior. We believe that letting the animals choose between these two events is the first step in answering the question of whether or not is training enriching, however more research needs to be done and suggestions for future research is discussed.

Looking back at 'looking back': operationalising referential gaze for dingoes in an unsolvable task.

This paper examined the performance of dingoes (Canis dingo) on the rope-pulling task, previously used by Miklósi et al. (Curr Biol 13:763-766, 2003) to highlight a key distinction in the problem-solving behaviour of wolves compared to dogs when in the company of humans. That is, when dogs were confronted with an unsolvable task, following a solvable version of the task they looked back or gazed at the human, whereas, wolves did not. We replicated the rope-pulling task using 12 sanctuary-housed dingoes and used the Miklósi et al. (Curr Biol 13:763-766, 2003) definition of looking back behaviour to analyse the data. However, at least three different types of look backs were observed in our study. We, then developed a more accurate operational definition of looking back behaviour that was task specific and reanalysed the data. We found that the operational definition employed greatly influences the results, with vague definitions potentially overestimating the prevalence of looking back behaviour. Thus, caution must be taken when interpreting the results of studies utilising looking back as behaviour linked to assistance seeking during problem solving. We present a more stringent definition and make suggestions for future research.

Multi-trophic resource selection function enlightens the behavioural game between wolves and their prey.

1. Habitat selection strategies translate into movement tactics, which reckon with the predator-prey spatial game. Strategic habitat selection analysis can therefore illuminate behavioural games. Cover types at potential encounter sites (i.e. intersections between movement paths of predator and prey) can be compared with cover types available (i) within the area of home-range-overlap (HRO) between predator and prey; and (ii) along the path (MP) of each species. Unlike the HRO scale, cover-type availability at MP scale differs between interacting species due to species-specific movement decisions. Scale differences in selection could therefore inform on divergences in fitness rewarding actions between predators and prey. 2. We used this framework to evaluate the spatial game between GPS-collared wolves (Canis lupus) versus caribou (Rangifer tarandus), and wolf versus moose (Alces alces). 3. Changes in cover-type availability between HRO and MP revealed differences in how each species fine-tuned its movements to habitat features. In contrast to caribou, wolves increased their encounter rate with regenerating cuts along their paths (MP) relative to the HRO level. As a consequence, wolves were less likely to cross caribou paths in areas with higher percentage of regenerating cuts than expected based on the availability along their paths, whereas caribou had a higher risk of intersecting wolf paths by crossing these areas, relative to random expectation along their paths. Unlike for caribou, availability of mixed and deciduous areas decreased from HRO to MP level for wolves and moose. Overall, wolves displayed stronger similarities in movement decisions with moose than with caribou, thereby revealing the focus of wolves on moose. 4. Our study reveals how differences in fine-scale movement tactics between species create asymmetric relative encounter probabilities between predators and prey, given their paths. Increase in relative risk of encounter for prey and decrease for predators associated with specific cover types emerging from HRO to MP scale analysis can disclose potential weaknesses in current movement tactics involved the predator-prey game, such as caribou use of cutovers in summer-autumn. In turn, these weaknesses can inform on subsequent changes in habitat selection tactics that might arise due to evolutionary forces.

Domestication has not affected the understanding of means-end connections in dogs.

Recent studies have revealed that dogs often perform well in cognitive tasks in the social domain, but rather poorly in the physical domain. This dichotomy has led to the hypothesis that the domestication process might have enhanced the social cognitive skills of dogs (Hare et al. in Science 298:1634-1636, 2002; Miklósi et al. in Curr Biol 13:763-766, 2003) but at the same time had a detrimental effect on their physical cognition (Frank in Z Tierpsychol 5:389-399, 1980). Despite the recent interest in dog cognition and especially the effects of domestication, the latter hypothesis has hardly been tested and we lack detailed knowledge of the physical understanding of wolves in comparison with dogs. Here, we set out to examine whether adult wolves and dogs rely on means-end connections using the string-pulling task, to test the prediction that wolves would perform better than dogs in such a task of physical cognition. We found that at the group level, dogs were more prone to commit the proximity error, while the wolves showed a stronger side bias. Neither wolves nor dogs showed an instantaneous understanding of means-end connection, but made different mistakes. Thus, the performance of the wolves and dogs in this string-pulling task did not confirm that domestication has affected the physical cognition of dogs.

Comparing wolves and dogs: current status and implications for human 'self-domestication'.

Based on claims that dogs are less aggressive and show more sophisticated socio-cognitive skills compared with wolves, dog domestication has been invoked to support the idea that humans underwent a similar 'self-domestication' process. Here, we review studies on wolf-dog differences and conclude that results do not support such claims: dogs do not show increased socio-cognitive skills and they are not less aggressive than wolves. Rather, compared with wolves, dogs seek to avoid conflicts, specifically with higher ranking conspecifics and humans, and might have an increased inclination to follow rules, making them amenable social partners. These conclusions challenge the suitability of dog domestication as a model for human social evolution and suggest that dogs need to be acknowledged as animals adapted to a specific socio-ecological niche as well as being shaped by human selection for specific traits.

Evaluating the logic of perspective-taking experiments.

In their recent study, Udell, Dorey, and Wynne (in press)[COMP: Ref. is LBE0034. Will have to be updated to (2011) here and in LBE0038, once page nos. are available.] showed that in a begging task, at least in some conditions, dogs as well as wolves preferentially approached a human partner who could see them in contrast to one whose eyes were occluded, and Udell et al. concluded that this success was dependent on the subjects' experiences with the specific occluder used. Here we argue, however, that since both partners expressed similar attentiveness towards the subjects by calling their names, Udell and colleagues' conclusion does not refer to the sensitivity of canines to others' attentiveness, but instead reflects the fact that the animals obeyed a familiar command better in a familiar context than in an unfamiliar one. Moreover, in contrast to Udell et al.'s conclusion, we believe that their data demonstrate that pet dogs can generalize the use of the visibility of human eyes to novel situations, showing a preference towards an attentive partner even if the eyes of the other partner are occluded in a novel way (e.g., having a bucket on his or her head). Finally, after presenting alternative interpretations of the results of the wolves tested by Udell and colleagues, we conclude that there is no evidence that wolves are sensitive to the attentional states of humans.

On the hunt for the gene of perspective taking: pitfalls in methodology.

In this commentary, we evaluate the methodology of Udell, Dorey, and Wynne's (Learning & Behavior, in press) experiment in controlling for environmental factors and argue that their conclusion is not supported. In particular, we emphasise that comparative studies on dogs and wolves need to ensure that both species enjoyed the same rearing history, are comparable in age, and have the same experience with the testing conditions. We also argue that the utilisation of shelter dogs does not control for genetic effects on social behaviour. Finally, we propose a synergetic model to account for both genetic and environmental effects on interspecific social behaviour in dogs and wolves.

Theory of mind in dogs?: examining method and concept.

In line with other research, Udell, Dorey, and Wynne's (in press) finding that dogs and wolves pass on some trials of a putative theory-of-mind test and fail on others is as informative about the methods and concepts of the research as about the subjects. This commentary expands on these points. The intertrial differences in the target article demonstrate how critical the choice of cues is in experimental design; the intersubject-group differences demonstrate how life histories can interact with experimental design. Even the best-designed theory-of-mind tests have intractable logical problems. Finally, these and previous research results call for the introduction of an intermediate stage of ability, a rudimentary theory of mind, to describe subjects' performance.

Reevaluating canine perspective-taking behavior.

Udell, Dorey, and Wynne (2011) demonstrated that both domesticated and nondomesticated canids-specifically, gray wolves-have the capacity to succeed on perspective-taking tasks, suggesting that dogs' ability to respond to the human attentional state is not a by-product of domestication alone. Furthermore, not all dogs were successful on the task. Instead, the occluder type used was a strong predictor of performance, indicating the important role of environment and experience for tasks of this type. Here, we address several commentaries reflecting on the methods and design of that study, as well as the interpretation of the results. We also discuss the positive shift toward more interactive approaches in the field of canine behavior and cognition. Finally, we question the functionality of describing canine social behavior in terms of theory of mind.

Theory of mind in dogs: is the perspective-taking task a good test?

Udell, Dorey, and Wynne (in press) have reported an experiment in which wolves, shelter dogs, and pet dogs all showed a significant preference for begging from a person who faced them (seer) over a person whose back was turned to them (blind experimenter). On tests with the blind person's eyes covered with a bucket, a book, or a camera, pet dogs showed more preference for the seer than did wolves and shelter dogs. We agree with the authors' position that most of these findings are best explained by preexperimental learning experienced by the subjects. We argue, however, that the perspective-taking task is not a good test of the domestication theory or of the theory of mind in dogs. The problem we see is that use of the perspective-taking task, combined with preexperimental learning in all the subjects, strongly biases the outcome in favor of a behavioral learning interpretation. Tasks less influenced by preexperimental training would provide less confounded tests of domestication and theory of mind.

Can your dog read your mind?: Understanding the causes of canine perspective taking.

Prior studies have documented the domestic dog's (Canis lupus familiaris) sensitivity to human attentional state, including a tendency to preferentially beg for food from attentive individuals and an ability to selectively perform forbidden behaviors when humans are not looking. Due to the success of dogs on perspective-taking tasks, some have hypothesized that domestic dogs may have theory of mind, or the ability to infer what other individuals know. Here we provide the first evidence that nondomesticated canids, grey wolves (Canis lupus), are also sensitive to human attentional state under some conditions. We also demonstrate that dogs do not display an undifferentiated sensitivity to all visual cues of attentional state. Rather, dogs are more sensitive to stimuli encountered in their home environment. Some dogs perform poorly on perspective-taking tasks. These findings have important implications for the interpretation of research designed to understand complex social cognition across species.

Are migrant and resident elk (Cervus elaphus) exposed to similar forage and predation risk on their sympatric winter range?

Partially migratory populations, where one portion of a population conducts seasonal migrations (migrants) while the other remains on a single range (residents), are common in ungulates. Studies that assess trade-offs between migratory strategies typically compare the amount of predation risk and forage resources migrants and residents are exposed to only while on separate ranges and assume both groups intermix completely while on sympatric ranges. Here we provide one of the first tests of this assumption by comparing the amount of overlap between home ranges of GPS-collared migrant and resident elk and fine-scale exposure to wolf predation risk and forage biomass at telemetry locations on a sympatric winter range in west-central Alberta, Canada. Overlap between migrant and resident home ranges increased throughout the winter, and both groups were generally intermixed and exposed to equal forage biomass. During the day, both migrants and residents avoided predation risk by remaining in areas far from timber with high human activity, which wolves avoided. However, at night wolves moved onto the grasslands close to humans and away from timber. Resident elk were consistently closer to areas of human activity and further from timber than migrants, possibly because of a habituation to humans. As a result, resident elk were exposed to higher night-time predation risk than migrants. Our study does not support the assumption that migrant and resident elk are exposed to equal predation risk on their sympatric range when human presence alters predation risk dynamics and habituation to humans is unequal between migratory strategies.

Adult, intensively socialized wolves show features of attachment behaviour to their handler.

Dogs' attachment towards humans might be the core of their social skillset, yet the origins of their ability to build such a bond are still unclear. Here we show that adult, hand-reared wolves, similarly to dogs, form individualized relationship with their handler. During separation from their handler, wolves, much like family dogs, showed signs of higher-level stress and contact seeking behaviour, compared to when an unfamiliar person left them. They also used their handler as a secure base, suggesting that the ability to form interspecific social bonds could have been present already in the common ancestor of dogs and wolves. We propose that their capacity to form at least some features of attachment with humans may stem from the ability to form social bond with pack members. This might have been then re-directed to humans during early domestication, providing the basis for the evolution of other socio-cognitive abilities in dogs.