Metacognition in dogs: Do dogs know they could be wrong?
ABSTRACT: In the current study, we investigated the question of whether dogs were sensitive to the information that they themselves had or had not acquired. For this purpose, we conducted three consecutive experiments in which dogs had to find a reward that was hidden behind one of two V-shaped fences with a gap at the point of the V. This setup allowed us to distinguish between selecting one of the fences by walking around it and seeking additional information by checking through the gap in the fence. We varied whether dogs had visual access to the baiting procedure or not. In addition, we manipulated the type and quality of reward as well as the time delay between baiting and choosing to analyze if the dogs' searching behavior was affected. Our results were partly consistent with the findings of Call (Animal Cognition, 13 (5), 689-700, 2010) with great apes, on whose findings we based our experiments. We found that dogs checked more often through the corner of the V-shaped fence when they had not seen where the reward was hidden. Interestingly, dogs rewarded with toys selected the correct fence more often than dogs rewarded with food. Even though dogs' performance was not affected by the food quality condition, dogs were significantly faster in fetching a high-quality food reward as opposed to a low-quality food reward. When testing whether forgetting and checking would increase as a function of delay, we found that although dogs slightly decreased in their success in finding the food when time delays were longer, they were not more likely to check before choosing. We show that - similar to apes - dogs seek additional information in uncertain situations, but their behavior in uncertain situations is less flexible compared to great apes.
Project description:One crucial element for the evolution of cooperation may be the sensitivity to others' efforts and payoffs compared with one's own costs and gains. Inequity aversion is thought to be the driving force behind unselfish motivated punishment in humans constituting a powerful device for the enforcement of cooperation. Recent research indicates that non-human primates refuse to participate in cooperative problem-solving tasks if they witness a conspecific obtaining a more attractive reward for the same effort. However, little is known about non-primate species, although inequity aversion may also be expected in other cooperative species. Here, we investigated whether domestic dogs show sensitivity toward the inequity of rewards received for giving the paw to an experimenter on command in pairs of dogs. We found differences in dogs tested without food reward in the presence of a rewarded partner compared with both a baseline condition (both partners rewarded) and an asocial control situation (no reward, no partner), indicating that the presence of a rewarded partner matters. Furthermore, we showed that it was not the presence of the second dog but the fact that the partner received the food that was responsible for the change in the subjects' behavior. In contrast to primate studies, dogs did not react to differences in the quality of food or effort. Our results suggest that species other than primates show at least a primitive version of inequity aversion, which may be a precursor of a more sophisticated sensitivity to efforts and payoffs of joint interactions.
Project description:Knowing that objects continue to exist after disappearing from sight and tracking invisible object displacements are two basic elements of spatial cognition. The current study compares dogs and apes in an invisible transposition task. Food was hidden under one of two cups in full view of the subject. After that both cups were displaced, systematically varying two main factors, whether cups were crossed during displacement and whether the cups were substituted by the other cup or instead cups were moved to new locations. While the apes were successful in all conditions, the dogs had a strong preference to approach the location where they last saw the reward, especially if this location remained filled. In addition, dogs seem to have special difficulties to track the reward when both containers crossed their path during displacement. These results confirm the substantial difference that exists between great apes and dogs with regard to mental representation abilities required to track the invisible displacements of objects.
Project description:Large carnivore conservation may be considered as successful in Sweden, as wolf (Canis lupus), lynx (Lynx lynx), brown bear (Ursus arctos), golden eagles (Aquila chrysaetos), and wolverine (Gulo gulo) populations have recovered from extinction or near extinction to viable populations during the last three decades. Particularly the wolf and lynx populations have returned at the cost of an increasing number of carnivore attacks on domestic livestock. To support coexistence between carnivores and livestock production, the Swedish authorities subsidise interventions to prevent or reduce the number of carnivore attacks. The most commonly used intervention is carnivore deterring fencing, and all livestock owners can apply for subsidies to build a fence. To receive reimbursement the fence must be approved by the authorities according to predefined criteria. An important part of any management aiming to be adaptive is evaluating interventions. In this paper we evaluate to what extent previously subsidised fences still meet the criteria 1-15 years after their approval. Of 296 fences that had received subsidies in the county of Värmland, 100 randomly selected fences were revisited in 2016. From this subsample 14% of the fences still met the initial criteria for subsidies. None of the fences that still fulfilled the criteria were more than 8 years old, whereas fences with identified failures occurred in all age groups. Of the 86 fences that failed to meet the criteria, construction failures were the most commonly occurring problem. Maintenance failures, wear and tear, only explain a minor part of the failures. To improve the quality of fencing, as well as the quality and longevity of the subsidies programme, there is a need for improved communication between authorities, and improved communication and support from the authorities to livestock producers before and during construction of fences, as well as more rigorous inspection when the fences are built.
Project description:Large predators can significantly impact livestock industries. In Australia, wild dogs (Canis lupus familiaris, Canis lupus dingo, and hybrids) cause economic losses of more than AUD$40M annually. Landscape-scale exclusion fencing coupled with lethal techniques is a widely practiced control method. In Western Australia, the State Barrier Fence encompasses approximately 260,000km2 of predominantly agricultural land, but its effectiveness in preventing wild dogs from entering the agricultural region is difficult to evaluate. We conducted a management strategy evaluation (MSE) based on spatially-explicit population models to forecast the effects of upgrades to the Western Australian State Barrier Fence and several control scenarios varying in intensity and spatial extent on wild dog populations in southwest Western Australia. The model results indicate that populations of wild dogs on both sides of the State Barrier Fence are self-sustaining and current control practices are not sufficient to effectively reduce their abundance in the agricultural region. Only when a combination of control techniques is applied on a large scale, intensively and continuously are wild dog numbers effectively controlled. This study identifies the requirement for addressing extant populations of predators within fenced areas to meet the objective of preventing wild dog expansion. This objective is only achieved when control is applied to the whole area where wild dogs are currently present within the fence plus an additional buffer of ~20 km. Our modelling focused on the use of baiting, trapping and shooting; however, we acknowledge that additional tools may also be applied. Finally, we recommend that a cost-benefit analysis be performed to evaluate the economic viability of an integrated control strategy.
Project description:Invasive predator control is often critical to improving the nesting success of endangered birds, but methods of control vary in cost and effectiveness. Poison-baiting or trapping and removal are relatively low-cost, but may have secondary impacts on non-target species, and may not completely exclude mammals from nesting areas. Mammal-exclusion fencing has a substantial up-front cost, but due to cost savings over the lifetime of the structure and the complete exclusion of mammalian predators, this option is increasingly being utilized to protect threatened species such as ground-nesting seabirds. However, non-mammalian predators are not excluded by these fences and may continue to impact nesting success, particularly in cases where the fence is designed for the protection of waterbirds, open to an estuary or wetland on one side. Thus, there remains a research gap regarding the potential gains in waterbird nesting success from the implementation of mammal-exclusion fencing in estuarine systems. In this study, we compared the nesting success of endangered Hawaiian Stilts (Ae'o; <i>Himantopus mexicanus knudseni</i>) within a mammal-exclusion fence to that of breeding pairs in a nearby wetland where trapping was the sole means for removing invasive mammals. We predicted success would be greater for breeding pairs inside the exclusion fence and the hatchlings inside the enclosure would spend more time in the nesting area than hatchlings at the unfenced site. During a single breeding season following construction of a mammal-exclusion fence, we used motion-activated game cameras to monitor nests at two sites, one site with mammal-exclusion fencing and one site without. Clutch sizes and hatch rates were significantly greater at the fenced site than the unfenced site, but time spent by chicks in the nesting area did not differ between sites. These results add to the mounting body of evidence that demonstrates the effectiveness of mammal-exclusion fencing in protecting endangered birds and suggests it can aid endangered Hawaiian waterbirds toward recovery. These results also suggest that the single greatest predatory threat to the Hawaiian Stilt may be invasive mammals, despite a host of known non-mammalian predators including birds, crabs, turtles, and bullfrogs, as the complete exclusion of mammals resulted in significant gains in nesting success. As additional fences are built, future studies are necessary to compare nesting success among multiple sites and across multiple seasons to determine potential gains in fledging success and recruitment.
Project description:The airflow field around wind fences with different porosities, which are important in determining the efficiency of fences as a windbreak, is typically studied via scaled wind tunnel experiments and numerical simulations. However, the scale problem in wind tunnels or numerical models is rarely researched. In this study, we perform a numerical comparison between a scaled wind-fence experimental model and an actual-sized fence via computational fluid dynamics simulations. The results show that although the general field pattern can be captured in a reduced-scale wind tunnel or numerical model, several flow characteristics near obstacles are not proportional to the size of the model and thus cannot be extrapolated directly. For example, the small vortex behind a low-porosity fence with a scale of 1:50 is approximately 4 times larger than that behind a full-scale fence.
Project description:Chimpanzees routinely follow the gaze of humans to outside targets. However, in most studies using object choice they fail to use communicative gestures (e.g. pointing) to find hidden food. Chimpanzees' failure to do this may be due to several difficulties with this paradigm. They may, for example, misinterpret the gesture as referring to the opaque cup instead of the hidden food. Or perhaps they do not understand informative communicative intentions. In contrast, dogs seem to be skilful in using human communicative cues in the context of finding food, but as of yet there is not much data showing whether they also use pointing in the context of finding non-food objects. Here we directly compare chimpanzees' (N = 20) and dogs' (N = 32) skills in using a communicative gesture directed at a visible object out of reach of the human but within reach of the subject. Pairs of objects were placed in view of and behind the subjects. The task was to retrieve the object the experimenter wanted. To indicate which one she desired, the experimenter pointed imperatively to it and directly rewarded the subject for handing over the correct one. While dogs performed well on this task, chimpanzees failed to identify the referent. Implications for great apes' and dogs' understanding of human communicative intentions are discussed.
Project description:Across three experiments, we explored whether a dog's capacity for inhibitory control is stable or variable across decision-making contexts. In the social task, dogs were first exposed to the reputations of a stingy experimenter that never shared food and a generous experimenter who always shared food. In subsequent test trials, dogs were required to avoid approaching the stingy experimenter when this individual offered (but withheld) a higher-value reward than the generous experimenter did. In the A-not-B task, dogs were required to inhibit searching for food in a previously rewarded location after witnessing the food being moved from this location to a novel hiding place. In the cylinder task, dogs were required to resist approaching visible food directly (because it was behind a transparent barrier), in favor of a detour reaching response. Overall, dogs exhibited inhibitory control in all three tasks. However, individual scores were not correlated between tasks, suggesting that context has a large effect on dogs' behavior. This result mirrors studies of humans, which have highlighted intra-individual variation in inhibitory control as a function of the decision-making context. Lastly, we observed a correlation between a subject's age and performance on the cylinder task, corroborating previous observations of age-related decline in dogs' executive function.
Project description:The use of fences to segregate wildlife can change predator and prey behaviour. Predators can learn to incorporate fencing into their hunting strategies and prey can learn to avoid foraging near fences. A twelve-strand electric predator-proof fence surrounds our study site. There are also porous one-strand electric fences used to create exclosures where elephant (and giraffe) cannot enter in order to protect blocs of browse vegetation for two critically endangered species, the black rhinoceros (Diceros bicornis) and the Grevy's zebra (Equus grevyi). The denser vegetation in these exclosures attracts both browsing prey and ambush predators. In this study we examined if lion predation patterns differed near the perimeter fencing and inside the elephant exclosures by mapping the location of kills. We used a spatial analysis to compare the predation patterns near the perimeter fencing and inside the exclosures to predation in the rest of the conservancy. Predation was not over-represented near the perimeter fence but the pattern of predation near the fence suggests that fences may be a contributing factor to predation success. Overall, we found that predation was over-represented inside and within 50 m of the exclosures. However, by examining individual exclosures in greater detail using a hot spot analysis, we found that only a few exclosures contained lion predation hot spots. Although some exclosures provide good hunting grounds for lions, we concluded that exclosures did not necessarily create prey-traps per se and that managers could continue to use this type of exclusionary fencing to protect stands of dense vegetation.
Project description:Sensitivity to inequity is thought to be an important mechanism for recognizing undesirable cooperative partners and thus crucial for the evolution of human cooperation . This link may not be unique to humans, as cooperative non-human primates also react to unequal outcomes , whereas non-cooperative species do not . Although this hypothesis has not been tested in non-primate species, studies revealed that pet dogs show a limited form of inequity aversion, responding to reward, but not quality inequity [4-6]. It has been proposed that this primitive form of inequity aversion was selected for during domestication and thus absent in their ancestors, wolves. Alternatively, wolves, which hunt, raise pups, and defend their territory cooperatively, are similarly inequity averse as non-human primates, or at least to the same degree as pet dogs. Testing similarly raised and kept pack-living dogs and wolves, we found both to be inequity averse when their partner was being rewarded but they were not for performing the same action. Additionally, both wolves and dogs reacted to receiving a lower-quality reward than their partner. These results suggest that the inequity response found in pack-living dogs and wolves is comparable to that observed in non-human primates; results from studies on pet dogs may be confounded by the dogs' relationship with humans. Consequently, our results suggest that inequity aversion was present already in the common-probably cooperative-ancestor of wolves and dogs and thus support the hypothesis of a close link of cooperation and inequity aversion.