Article

Age-graded dominance hierarchies and social tolerance in packs of free-ranging dogs Roberto Bonanni, Simona Cafazzo,b, Arianna Abis, Emanuela Barillari, Paola Valsecchi, and Eugenia Natoli Behavioral Ecology (2017), https://doi.org/10.1093/beheco/arx059

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Abstract

It is believed that domestic dogs rarely form packs with age-graded hierarchical structures similar to those found in wolves. Dog-wolf comparisons in captivity suggest that human control has reduced dog dependency on cooperation with conspecifics, resulting in a more despotic dominance order. However, free-ranging dogs are under stronger natural selection than purebred dogs. They are dependent on companions’ social support but usually exhibit lower reproductive skew than wolves, possibly because access to easily available human-derived food may have relaxed within-group competition. We investigated social dominance in 5 packs of mongrel dogs living in a free-ranging or semifree-ranging state. We aimed at replicating the findings of the few studies that detected a dominance hierarchy in dogs using a larger sample of packs. Additionally, we provided behavioral measures of social tolerance. We found that a linear hierarchy existed in all packs studied and that the rank order was positively related to age in all packs but one. In 2 packs in which testing was possible, age was a better predictor of dominance than body size. Potentially injurious aggression was very rare. Hierarchy steepness in dogs was similar to that found in wolves and in tolerant primates. Submissive reversals were more common in dogs than in wolves. These results suggest that age-graded hierarchies in dogs are more common than previously thought, that rank is not usually acquired through fighting because subordinates rely on the guidance of elders, and contradict the view that domestication has increased despotism in dogs.

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... Age can also be expected to affect social behaviors in dogs (Howse et al., 2018;Rosado et al., 2012). Social rank is likely to change with age (Bonanni et al., , 2017Cafazzo et al., 2010;Pal et al., 1998), which might affect at least some social behaviors like observational learning (Pongrácz, 2014;Pongrácz et al., 2008) and leadership (Ákos et al., 2014). ...
... Previous work has reported that aging and in particular pathological aging could affect social responsiveness in dogs (Howse et al., 2018;Rosado et al., 2012), although it is difficult to separate these observations from a general decline in activity. In addition, age also correlates with social rank in canines (Bonanni et al., , 2017Pal et al., 1998). Social rank by itself has been shown to affect some social behaviors, for example, social learning across several species (Nicol & Pope, 1999;Pongrácz, 2014), but also active versus passive approach to social interaction (Schenkel, 1967), with dogs of higher rank being often the recipients rather than initiators of ritualized greetings . ...
... Until recently, much of what we knew about the body language and social behavior of dogs and the closely related wolf was derived from field observations in feral dogs and captive wolves (Bonanni et al., , 2017Cafazzo et al., 2014;Pal et al., 1998;Schenkel, 1967;Zimen, 1981). The companion dog, on the other hand, was mostly approached with rigid experimental setups and studies investigating its spontaneous social behavior under natural conditions are to date fewer in comparison and more recent overall (Ákos et al., 2014;Howse et al., 2018;Smuts et al., 2016;Trisko & Smuts, 2015;Van Der Borg et al., 2015). ...
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Introduction: The aim of this study was to explore spontaneous social interactions between dyads of unfamiliar adult dogs. Although intraspecific encounters are frequent events in the life of pet dogs, the factors that might influence encounters, such as sex, dyad composition, reproductive status, age, and state of cohabitation (keeping the dogs singly or in groups), remained unexplored. Methods: In this study, we assigned unfamiliar, non-aggressive dogs to three types of dyads defined by sex and size. We observed their unrestrained, spontaneous behaviors in an unfamiliar dog park, where only the two dogs, the owners, and experimenter were present. Results: We found that the dogs, on average, spent only 17% of the time (less than 1 min) in proximity. Sex, dyad composition, reproductive status, and age influenced different aspects of the interactions in dyads. Female dogs were more likely to initiate the first contact in their dyad but later approached the partner less frequently, were less likely to move apart, and displayed less scent marking. Following and moving apart were more frequent in male-male interactions. Neutered dogs spent more time following the other dog and sniffed other dogs more frequently. The time companion dogs spent in proximity and number of approaches decreased with age. Conclusion: The study provides guidance for dog owners about the outcomes of intraspecific encounters based on the dog's age, sex, and reproductive status, as well as the sex of the interacting partner.
... We did not observe such tendencies and so we can only speculate that at such a young age, not only size but the progression in the development of motor skills, and probably some other individual factors, may play a more important role to be a "winner" than body size. Similarly to these speculations, a study on packs of free-ranging dogs [39] revealed that age was a better predictor of dominance than body size. Therefore, we can only assume that age would also be a better indicator for winning within the play context. ...
... Bonanni et al. [39] hypothesized that dogs under strong artificial selection may exhibit a more despotic dominance style than free-ranging dogs. According to Bonanni et al. [39], dogs may be more cooperative than is usually supposed and based on their results, contradicted the view that domestication has increased despotism in dogs. ...
... Bonanni et al. [39] hypothesized that dogs under strong artificial selection may exhibit a more despotic dominance style than free-ranging dogs. According to Bonanni et al. [39], dogs may be more cooperative than is usually supposed and based on their results, contradicted the view that domestication has increased despotism in dogs. ...
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The symmetry of social play in Canids has been previously studied, especially in wolves, free-ranging dogs, and within mixed-aged groups, however our study focused on symmetry and asymmetry within play interactions in two litters (14 puppies) of German Shepherd dogs (GSDs). At the age of 7 weeks, we evaluated 1287 dyadic interactions (litter 1: n = 339 interactions, litter 2: n = 948 interactions), and at the age of 9 weeks we evaluated 1255 dyadic interactions (litter 1: n = 433 interactions, litter 2: n = 822 interactions). Dyadic interactions were observed and the winning indexes were calculated for 43 pairs (dyads). The groups of puppies studied were all the same age, therefore we focused on the aspects of sex and body size as primary variables. The weight and chest circumference of all puppies were measured. The distribution of interactions showed a slight inclination to mixed-sex dyads, but we did not obtain any statistically significant results concerning the impact of body size on play interactions. Symmetry in play was observed within litter 1 at the age of 7 weeks and at the age of 9 weeks, and within litter 2 at the age of 7 weeks. Since the number of puppies in this study was too small, these results should be interpreted regarding this limitation, and cannot be generalized to a larger population of domestic dogs nor the GSD breed. In further studies, it would be interesting to compare larger samples of different breeds, under different breeding conditions, and the effect of the environment on the style of social play.
... Pups are mainly raised by their mothers, but female-allocare (e.g., grandmother care) and paternal care have also been observed; males often provide care in the form of play and protection [15,[30][31][32][33][34][35]. Like wolves, some studies found linear dominance hierarchies in dog packs (e.g., [25,36]), particularly based on age [13,37], while others did not (e.g., [12,33,38,39]). Hierarchies are generally also present in pet dogs and dogs in shelters [40][41][42]. ...
... When competing for food, agonistic interactions may be frequent [26,47,48]. However, it seems that intragroup aggression in free-ranging dogs is characterized by low intensity [37,48], possibly because high-ranking dogs monopolize food, while lower ranking dogs retreat [13,[49][50][51]. Furthermore, in dog packs kept in enclosures, low rates of mild aggression between pack members were observed when compared to similarly raised wolves; however, when agonistic interactions occurred, they were often of high intensity [49]. ...
... Similar to wolves, many dog packs do defend their territories and food sources against other packs [26,32,47,48]. However, free-living dogs, in contrast to wolves, rarely engage in severe fighting when meeting [26,28,32,37,48,52,53]. Hence, dog packs seem to be socially less closed than wolf packs, which could be the basis for greater inter-pack tolerance in dogs as compared to wolves [25]. ...
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Domestication has affected the social life of dogs. They seem to be less dependent on their pack members than wolves, potentially causing dogs to be more alert towards their environment, especially when resting. Such a response has been found in dogs resting alone compared to wolves in the same situation. However, as this may be influenced by social context, we compared alertness (i.e., degree of activation along the sleep–wake continuum—measured via cardiac parameters) of pack-living and enclosure-kept dogs in two conditions: (1) alone, and (2) with pack members, and in two states of activation: (1) inactive wakefulness, and (2) resting. We found that when dogs were resting alone, alertness was higher than when resting in the pack; individual alertness was potentially influenced by social rank. However, alertness was similar in the two conditions during inactive wakefulness. Thus, depending on social context, familiar conspecifics may still provide support in dogs; i.e., domestication has probably only partly shifted the social orientation of dogs from conspecifics to humans. We suggest that cardiac responses of dogs may be more flexible than those of wolves because of their adaptation to the more variable presence of humans and conspecifics in their environment.
... While they behave cooperatively [16,17], they typically exhibit a promiscuous mating system [18], which would be expected to reduce reproductive skew. Free-living dogs have previously been reported to exhibit a linear dominance hierarchy [14,[19][20][21], not dissimilar to that in wolves Canis lupus [22,23], in which older individuals are dominant over younger ones and males are dominant over females of similar age. However, unlike free-living dogs, wolves frequently live in closely related family groups, in which only the dominant pair reproduce [23]. ...
... Specifically, we (1) construct social networks based on aggressive, ritualized dominance and submissive behaviours, (2) test how ritualized dominance and aggressive behaviours vary with social rank, (3) determine regions of instability in the network and (4) examine whether rank instability is costly to individuals through increasing the frequency of aggressive interactions. Our study of social behaviour in dogs, where dominance is conspicuous and the costs of aggression can include prolonged, energetically costly interactions (such as chasing and physical fighting [19]) that carry a potential risk of injury [21], provides evidence for greater instability in dominance relationships and increased aggression in the centre of dominance hierarchies. We suggest that the patterns exhibited by dogs living in a complex social network may be a feature of groups composed of animals of different ages and sexes, and have important implications for the evolution of behavioural strategies within such groups, by generating rank-specific variation in the benefits of hierarchy formation. ...
Article
Dominance hierarchies are widespread in animal societies and reduce the costs of within-group conflict over resources and reproduction. Variation in stability across a social hierarchy may result in asymmetries in the benefits obtained from hierarchy formation. However, variation in the stability and behavioural costs of dominance interactions with rank remain poorly understood. Previous theoretical models have predicted that the intensity of dominance interactions and aggression should increase with rank, but these models typically assume high reproductive skew, and so their generality remains untested. Here we show in a pack of free-living dogs with a sex-age-graded hierarchy that the central region of the hierarchy was dominated by more unstable social relationships and associated with elevated aggression. Our results reveal unavoidable costs of ascending a dominance hierarchy, run contrary to theoretical predictions for the relationship between aggression and social rank in high-skew societies, and widen our understanding of how heterogeneous benefits of hierarchy formation arise in animal societies.
... Age based hierarchies where individuals queue for dominance occur in many mammalian societies, including African elephants, Loxodonta africana (Archie et al. 2006), chimpanzees, Pan troglodytes (Foerster et al. 2016) and free-ranging dogs, Canis lupus familiaris (Bonanni et al. 2017), as well as in several cooperatively breeding mammals, such as dwarf mongooses, Helogale parvula, wolves, Canis lupus and wild-dogs, Lycaon pictus (Creel et al. 1992;Creel 2005). Although the weight and condition of individuals are commonly correlated with their status (Veiberg et al. 2004;Vervaecke et al. 2005) few studies have been in a position to investigate their effects on the likelihood of status acquisition itself. ...
... The reproductive costs of subordinate males often increase with their numbers Lardy et al. 2012), as the dominant males become increasingly energetically constrained and unable to exclude multiple males from breeding opportunities, especially when there are high numbers of females and their oestrus is synchronised (Altmann 1962;Kappeler & Port 2008;Dubuc et al. 2011;Lambert et al. 2018). Subordinate males can also be a threat to a dominant's social status, and should the resource holding potential of a subordinate substantially exceed the dominant, the subordinate may challenge and displace them from their position (Hasegawa & Kutsukake 2014;Bonanni et al. 2017). ...
Thesis
In group-living species with strong reproductive skew, acquiring a position of dominance is often essential for maximising fitness, and where the frequency of lifetime dominance acquisition is low, substantial variation in fitness among individuals can arise. However, even among dominant individuals there is still substantial variance in fitness attainment, driven by processes such as the maintenance of status, fecundity, and fertility. In this thesis, to understand better the variation in fitness among individuals, I use 26 years of long-term data to investigate the acquisition of dominance and the subsequent maintenance of status and group persistence in a population of cooperatively breeding meerkats, Suricata suricatta, located in the Southern Kalahari. In Chapters 3 and 4, I characterise the distinct routes that subordinates of both sexes pursue to acquire dominance. While there is variation in the frequency that certain dominance routes are used, I find no substantial differences between routes in the traits that determine the acquisition of dominance, the length of tenures or the reproductive success of dominants. In Chapter 5, I distinguish between the reproductive consequences of intrasexual competition from within and outside the group for dominant males. This reveals that while resident immigrant subordinate males compete with the dominant male for reproduction, they also buffer against reproductive competition from outside the group, thereby offsetting their reproductive costs. In Chapter 6, I investigate the factors that influence the maintenance of both sexes’ dominance tenures, while accounting for the distinct causes of tenure loss. I show that heavier dominants are more likely to maintain their position and that dominants of both sexes experience similar levels of within-group intrasexual competition, with increasing numbers of resident competitors increasing the risk of displacement. In addition, dominant males are uniquely vulnerable to extra-group takeovers and resident subordinate males appear to aid in the defence of the group, with higher numbers of subordinate males reducing takeover risk. Furthermore, males are also distinct from female dominants in that a substantial number abandon their dominance, a process that I find is associated with the availability of reproductive opportunities within the group. Finally in Chapter 7, I characterise the processes influencing group persistence, which is important for both the maintenance of a dominant’s tenure and ensuring the persistence of their lineage. I show that groups iii can persist for over a decade and that maintaining a large group size is essential for maximising group longevity. I also find that an endemic form of tuberculosis, Mycobacterium suricattae, plays a considerable role in the failure of groups, being associated with the failure of most long lived groups in the population.
... Importantly, the relationships tend to be less strong in larger dog packs and to be more specifically related to the formal dominance style [26,27,45]. Age, sex, leadership and reproductive success have also been found to be related to dominance status in free ranging and/or pet dogs [24,26,[46][47][48][49]. Theoretical models predict that intra-specific dominance, especially when tied to consistent leadership, is only useful in small groups characterized by asymmetric distribution of experience and familiarity with the environment [50,51]. ...
... Older dogs were more likely to be classified as dominant than younger dogs, in agreement with the literature for both wolves and dogs [22,23,46,47,79]. One-year old dogs had a 50% probability of being classified as dominant, which seems high given their age and amount of experience. ...
Article
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Social dominance is an important and widely used concept, however, different interpretations have led to ambiguity in the scientific literature and in popular science. Even though in ethology dominance is an attribute of dyadic encounters, and not a characteristic of the individual, ‘dominance’ has often been referred to as a personality trait in animals. Since few studies have specifically examined the link between personality traits and dominance status, we investigated this in dogs living in multi-dog households using a questionnaire, which required owners to specify whether the dog had a dominant or submissive status, and comprised items of both the features of the individual (i.e. personality traits) and previous social experience (interactions with group members and strangers). Four distinct personality factors emerged from 23 behavioural items by principal component analysis, labelled as assertiveness, trainability, intraspecific aggression and independence. Binomial logistic regression was used to examine how the demographic information of the dogs and the personality factors predicted the owner’s estimate of the dog’ status as dominant or submissive. The personality factor assertiveness accounted for 34% of the variance in dominance status, trainability 5% and dog age contributed 4%. Dogs perceived as dominant scored more highly on the factors assertiveness and trainability, which can help explain why ‘dominance’ has often been suggested to be a personality trait, rather than a dyad-specific social status according to different traditions in behavioural research. Similar to the ‘social dominance’ trait in humans, owner ascribed dominance showed a quadratic trajectory in cross-sectional mean change across the lifespan, increasing during adulthood and then maintaining high levels until old age. Overall, our study proposes a multifactorial background of dominance relationships in pet dogs, suggesting that not only previous experience of social interactions between individuals but also age and personality traits influence owner perceived dominance status in multi-dog households.
... We used the definitions provided by Bonanni et al. (2017). For convenience of the reader, we presented them here -Aggressionthreatening (pointing, staring, curling of the lips, baring of the canines, raising the hackles, snarling, growling, and barking), physical fighting, chasing, and biting. ...
Thesis
Full-text available
Co-habiting with humans in an urban ecological space requires adequate variation in a species’ behavioural repertoire. The eco-ethology of many urban species have been shown to be modified due to human activities leading to urban adaptations. Dogs (Canis lupus familiaris) are the first species to have been domesticated and have a long evolutionary history of co-habitation with humans. In the last two decades, scientists have investigated various questions on dogs pertaining to its domestication. In fact, no other species belonging to the family Canidae has received such attention in the scientific world. Unfortunately, majority of the work was confined to pet dogs in the western countries. Pet dogs are the result of artificial breeding based on desirable traits and their activities are typically determined by their owners. Free-ranging dogs found in most of the developing countries, on the other hand, represent a naturally breeding population without direct human supervision. Studying free-ranging dogs can thus provide us with crucial insights on the ecology and evolution of dogs in greater detail. Close to 80% of the world’s dog population is free-ranging, yet scientific studies on them are almost non-existent. Scientists have realised the importance and need of studying these dogs very recently to address various facets of the much debated domestication event. Free-ranging dogs are a highly successful urban-adapted species living in all possible human habitats in the developing countries. The dog-human relationship is highly complex and possess multiple trajectories. For example, these dogs depend on human subsidized food, choose dens near human households, yet receive a range of negative stimuli from humans; mortality of these dogs is mostly influenced by humans. In this thesis, we tried to answer questions relating to the dog-human relationship on Indian streets. My thesis involved an interdisciplinary approach where behavioural, cognitive, and ecological aspects are discussed to shed light on the evolution of the dog-human relationship. We began the work by looking at the natural history of free-ranging dogs in India. We collected data on the abundance of dogs and the distribution of their potential food resources, across India. Moreover, we recorded the sex ratio, group size, and behaviours of dogs at different study locations. We characterized study areas with regard to human activity levels by estimating human flux or movement and categorised them into low, intermediate and high flux zones. Our findings clearly suggested varying distribution of dogs and their food resources across different microhabitats in India. While a direct effect of food resource was not found, human flux significantly predicted the distribution of dogs. Moreover, we found a strong impact of changing human flux on the abundance and behavioural activity of free-ranging dogs. In the next section, we investigated the intra-group dynamics of dogs from the perspective of long-debated dominance-rank relationships. We looked at the steepness and linearity of agonistic and formal dominance hierarchies of groups of dogs from intermediate and high human flux zones. Our study did not reveal any clear dominance hierarchy among the free-ranging dogs, either in the intermediate or high human flux zones. The overall frequencies of interactions between the group members were found to be quite low, with many unknown interactions between for several dyads. We also proposed the use of subtle behavioural cues to maintain hierarchy rather than showing frequent behavioural exchanges in dogs. Findings from the study further led us to test free-ranging dogs’ interactions with humans. We found that these dogs interact with humans more compared to their conspecifics. Interestingly, we noticed that dogs rarely initiated behaviours towards humans, while humans played the predominant role in initiating both positive and negative behaviours towards dogs. We concluded that humans are a predominant part of the interaction network of the Indian free-ranging dogs. This opened up a window of testing dogs’ physical and social cognitive abilities. We found that free-ranging dogs lack the ability to persist on physical cognitive tasks and are poor performers like pet dogs. A higher dependence on humans is thought to be a key factor restricting dogs from persisting on an unfamiliar task. Interestingly, free-ranging dogs, as scavengers, showed competence while solving a familiar task, though task difficulty remained a factor that could not be disentangled. A partial dependence on humans was assumed to be the outcome of their long-history of co-evolution which resulted in a reduced problem-solving capacity in dogs. Surprisingly, a role of social facilitation was observed which predicted improved performances in both familiar and unfamiliar tasks. Free-ranging dogs like any other urban species are typically found to be aversive towards making direct physical contact with unfamiliar humans. The sociability of dogs was found to correlate with human flux, suggesting a role of life experience in shaping the personalities of these dogs. Dogs were shown to understand different human social cues and respond accordingly. The dogs in groups were bolder while responding to threatening cues from humans than in the solitary condition. Using two studies, we showed their ability to understand human pointing gestures, both simple and complex. The behavioural states of the dogs were heavily found to influence their responses towards humans. Dogs were found to be anxious or fearful while encountering an unfamiliar human. Interestingly, we found a crucial role of positive socialization in the form of petting in modifying such behavioural states of dogs and further building a strong dog-human relationship. In summary, this thesis provides unprecedented inputs into the current understanding of the evolution of dog-human relationship. The findings are not only restricted to the scientific advancement but may also be helpful in mitigating the growing doghuman conflict on the streets in India, by enhancing an understanding of the dynamics of the relationship between the two species, that might enable better management strategies.
... Wolves, like most wild canids, form family packs and breed cooperatively, whereas dogs do not usually show alloparenting behavior (Lord et al., 2013; but see Paul and Bhadra, 2018). Freeranging dogs may live solitarily, but many form packs of two or more (2-4: Daniels and Bekoff, 1989;2-5: Krauze-Gryz and Gryz, 2014;4-11: Bonanni et al., 2011) and even up to 42 individuals (Cafazzo et al., 2014), with a linear, hierarchical social structure (Cafazzo et al., 2014;Bonanni et al., 2017). The relationship between GC concentrations and cooperative breeding has received much attention. ...
Article
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Dogs are exceptionally well adapted to life close to humans, and alterations in their endocrine system during the domestication process may be an underlying mechanism. In particular, it has been suggested that low circulating cortisol concentrations in conjunction with simultaneously high oxytocin concentrations may have resulted in dogs' increased docility ('selection for tameness' hypothesis) and heightened propensity to interact and form relationships with humans ('hypersociability' hypothesis) compared to wolves. To investigate this, we analyzed cortisol and oxytocin metabolite concentrations from urine samples of hand-raised, pack-living domestic dogs and their non-domestic relatives, grey wolves. Based on the hypotheses outlined above, we predicted lower cortisol but higher oxytocin concentrations in dogs than wolves. In contrast to our prediction, we found higher cortisol concentrations in dogs than wolves. However, oxytocin concentrations were higher in dogs compared to wolves although the effect was relatively small. Indeed, male dogs had the highest oxytocin concentrations while female dogs' oxytocin concentrations were comparable to wolves'. Feeding status, reproductive phase, and conspecific social interactions also significantly affected cortisol and oxytocin concentrations. Furthermore, we compared two methods of correcting for variable water content of urine samples. We discuss our results in light of physiological and behavioral changes during domestication and highlight the importance of accounting for confounding variables in future studies.
... With this result, we can suggest that cattle, like other species, may use affiliative bonds as a strategy for obtaining food. In the case of dogs (Bonanni et al., 2017), monkeys (Roubovaá et al., 2015;Xia et al., 2013) and horses (Fureix et al., 2012), affiliative bonds are described as exchange of favours in a way that uses social tolerance in exchange for obtaining food. In primates, animals of lower social rank are affiliated with upper ranks because it is an effective way to obtain food (Naud et al., 2016). ...
Article
The aim of this study was to evaluate the influence of social position and degree of affinity among heifers attempting to access limited feed supplement. This study was divided into two stages: (1) observation of behaviour at the paddock and (2) arena tests. In stage 1, we measured socio-positive interactions (licking and frequency of proximity among animals) and agonistic interactions in a herd of nineteen dairy heifers. The frequency of proximity between animals of different dominance ranks was used as a measure of the degree of affinity. This measure was considered for two arena tests. In the first we compared pairs with high (PHda, n = 7) and low (PLda, n = 7) degree of affinity. In the second arena test a third neutral middle-ranking animal was included, and we compared triads with a pair with high (THda, n = 7) or low (TLda, n = 7) degree of affinity. In the arena tests, feed supplementation was offered to pairs and triads, and latency to access food, time spent at the feeder, and agonistic interactions were measured. The degree of affinity influenced (p < 0.05) the time at the feeder of the low-ranking animals at the arena test with pairs, but not with triads. Low-ranking animals remained longer (10.36 vs. 8.96 min; p ≤ 0.02) at the feeder in pairs with high degree of affinity. However, latency wasn’t affected by rank nor by affinity among pairs (p ≥ 0.13) High-ranking animals remained longer at the feeder in both treatments (p ≤ 0.02). The latency of low-ranking animals to access the food tended (p = 0.084) to be lower in triads of low degree of affinity. Despite degree of affinity, low-ranking animals were the main victims of aggressive interactions throughout the experimental period. We concluded that the degree of affinity among animals could influence access to food, but that it could not overcome the effects of social dominance.
... Schenkel (1967) "active submission"), which likely function as attempts to form or enhance social bonds with another dog. Topographically (and perhaps functionally) similar behaviours are seen in dog mother-pup interactions, as well as in feral dogs and wolf packs, with younger group members typically directing the behaviour toward older dogs (e.g., Bonnani et al., 2017;Mech, 1999). ...
Article
This study examines the activity budgets and social behaviours initiated and received by 69 focal dogs in an off-leash dog park for 400 seconds after entry, a time of high activity about which little is known. Using motivationally-neutral labels for social behaviour categories, we describe the frequency of behaviours, and correlations among them. We then examine these relationships in the context of proposed functions for some behaviours in dogs, in terms of information gathering and communication, including visual and tactile signalling. Time spent with other dogs decreased rapidly over the visit, and much of this early interaction involved greeting the park newcomer. Snout-muzzle contact behaviours were ubiquitous, while other behaviours were rarely observed, including aggressive behaviours. Correlations among certain non-contact behaviours initiated and received by focal dogs are consistent with their function as visual signals that may influence the continuation and form of social interactions, and their possible role in social mimicry (i.e., play bow and pull-rear away). Age, sex, and number of dogs present in the park influenced specific aspects of dogs' activity budgets, and a few behaviours. This ethological study provides fundamental data on dog social behaviour in dog parks, about which surprisingly little has been published.
... However, when a hierarchy was detected in a dog group, several parameters have been shown to covary with dominance status, such as age, sex, and personality. Older dogs were found to be more often dominant than young individuals (Mech, 1999;Peterson et al., 2002;Bonanni et al., 2010;Bonanni et al., 2017;Cafazzo et al., 2010;Trisko & Smuts, 2015). Therefore Bradshaw, Blackwell & Casey (2016) suggested that a simple rule of thumb could help to explain formal dominance in dogs: ''in order to be allowed to stay in the group, perform affiliative behaviour towards all the members of the group older than you are''. ...
Article
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Dominance is well defined in ethology, debated in psychology, and is often unclear among the dog owning public and in the press. However, to date, no study has examined how owners perceive dominance in dogs, and what different behaviours and personality types are used to describe dominant and subordinate individuals. A questionnaire study was launched to investigate the external validity of owner-derived estimates of dominance in dog dyads sharing the same household (N = 1,151). According to the owners, dogs rated as dominant (87%) have priority access to resources (resting place, food, and rewards), undertake certain tasks (defend and lead the group, bark more), display dominance (win fights, lick the other's mouth less, and mark over the other's urine), share certain personality traits (smarter, more aggressive and impulsive), and are older than their partner dog (all p < 0.0001). An age-related hypothesis has been suggested to explain dominance in dogs; but we found that dog age did not explain the occurrence of dominance related behaviours over the owners' estimate of dominance status. Results suggest that owner-derived reports of dominance ranks of dogs living in multi-dog households correspond to ethologically valid behavioural markers of dominance. Size and physical condition were unrelated to the perceived dominance. Surprisingly, in mixed-sex dyads, females were more frequently rated as dominant than males, which might correspond to a higher proportion of neutered females in this subgroup. For future studies that wish to allocate dominance status using owner report, we offer a novel survey.
... Although 'feral' dogs that live removed from humans and base their survival on hunting small prey exist [27,[36][37][38], the majority of free-ranging dogs are largely scavengers [39][40][41][42][43][44][45] that rely on resources provided by human activity [45]. Free-ranging dogs living in urban areas have a close association with humans and tend to be solitary or form smaller groups compared to those living in rural areas that are more independent from humans and tend to form bigger groups [35,36] with a well-defined social structure [46,47]. ...
Article
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Persistence in object manipulation has been consistently associated with problem-solving success and it is known to be affected, at the individual level, by life experience. Differences in life experiences are particularly poorly studied in the problem-solving context and mainly refer to the comparison between wild and captive animals. Dogs represent interesting study subjects, since dog populations differ widely in their life experiences. In this comparative study we investigated subjects' persistence when presenting a novel object containing food that could not be accessed (impossible task) to three dog populations with very diverse life experiences: free-ranging village dogs (in Morocco), pet dogs (in Vienna) and captive pack living dogs (Wolf Science Center-WSC). We found that pet dogs and captive dogs (WSC) were more manipulative and persistent than free-ranging dogs. The low persistence of free ranging-dogs is unlikely the effect of a lack of exposure to objects, since they are confronted with many human’ artefacts in their environment daily. Instead, we suggest that the higher persistence of captive dogs and pet dogs in comparison to free-ranging dogs might be due to their increased experience of human-mediated object interaction. This provides subjects with a socially guided experience in manipulating and interacting with objects increasing their motivation to engage in such tasks.
... and finally a list of sources (please see abbreviation key at the end of the Dietz (1984); 12, Lamprecht (1979); 13, Wright et al. (2010); 14, Vanak and Gompper (2007); 15, ; 16, Liu et al. (2007); 17, Wang et al. (2008); 18, Stuart and Stuart (1997); 19, Lindsay and Macdonald (1986); 20, Kamler et al. (2004); 21, Kitchen et al. (2006); 22, Harris and Yalden (2008); 23, Hunter (2011) groups called "packs," which have the advantage of enabling them to tackle larger prey when hunting with more individuals (Sillero-Zubiri et al. 2004). Typically, the older, more experienced individuals lead the pack, and in most cases, a hierarchy is formed, and the dominant male and female are usually the only pack members to breed (Bonanni et al. 2017;Cafazzo et al. 2014;Kubinyi and Wallis 2018;Sillero-Zubiri et al. 2004). Surprisingly, for some species, detailed information about their social behavior is lacking (e.g.,, the short-eared dog (Atelocynus microtis), Sechuran fox (Lycalopex sechurae), and pale fox (Vulpes pallida); please refer to the "Social behavior" section of Table 1). ...
Chapter
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Canine life history describes the reproduction, growth, and survival patterns for species in the mammalian Canidae, a family within the Carnivora order with multiple species, including dogs, wolves, foxes, jackals, coyotes, and other dog-like mammals.
... Each individual dog is identified using a three letter code. See Figure 1 for a visualization of this network and see [3] for more discussion. Nodes are labeled in grey if the difference in rankings is less than five. ...
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In adversarial networks, edges correspond to negative interactions such as competition or dominance. We introduce a new type of node called a low-key leader in adversarial networks, distinguished by contrasting the centrality measures of CON score and PageRank. We present a novel hypothesis that low-key leaders are ubiquitous in adversarial networks and provide evidence by considering data from real-world networks, including dominance networks in 172 animal populations, trading networks between G20 nations, and Bitcoin trust networks. We introduce a random graph model that generates directed graphs with low-key leaders.
... It is becoming more evident that dominance rank and reproductive success can be affected by factors other than body size. For example, age (e.g., Cervus elaphus L., [71]; Rattus rattus L., [72]; Canis familiaris L., [73]), prior experience (e.g., Xiphophorus helleri, Heckel 1848, [74]), or prior possession of resources (e.g., Sorex araneus L., [75]), as well as formation of male coalition (e.g., Gorilla gorilla, Savage & Wyman 1847 [76]) can influence the relationship. ...
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Welfare and management decisions for unowned free-ranging cats in urban environments should no longer be based on knowledge about behavioural ecology of solitary cats living and breeding in more natural ‘wild’ environments. We provide evidence that urban free-ranging domestic cats in the Anthropocene have responded to rapidly changing environments, such as abundance of food and higher population densities of conspecifics by adapting their behaviour (behavioural plasticity—the ability of a genotype (individual) to express different behaviours according to its environment) and social organisation to living in complex social groups, especially those living in colonies. Urban free-ranging cats are now more social, as demonstrated by different breeding patterns, lower infanticide, more frequent affiliative interactions in general, and different spatial groupings. We argue that this knowledge should be disseminated widely, and inform future research and strategies used to manage free-ranging cats across environments. Understanding behavioural plasticity and other recently evolved traits of domestic cats may lead to management strategies that maximise health and welfare of cats, wildlife, and humans—otherwise domestic cat behaviour may be ‘misunderstood’. Importantly, interdisciplinary research using expertise from biological and social sciences, and engaging human communities, should evaluate these management strategies to ensure they maintain optimal welfare of free-ranging domestic cats while preserving biodiversity and protecting wildcats.
... It is becoming more evident that dominance rank and reproductive success can be affected by factors other than body size. For example, age (e.g., Cervus elaphus L., [71]; Rattus rattus L., [72]; Canis familiaris L., [73]), prior experience (e.g., Xiphophorus helleri, Heckel 1848, [74]), or prior possession of resources (e.g., Sorex araneus L., [75]), as well as formation of male coalition (e.g., Gorilla gorilla, Savage & Wyman 1847 [76]) can influence the relationship. ...
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The free-ranging unowned domestic cat (unowned—not under human control with respect to movement and sexual behaviour), living in the Anthropocene, can live a strictly solitary life or in socially structured groups, depending on environmental conditions. This paper explores the evidence for evolution of new traits (behavioural, morphological, physiological, immunological) in domestic cats, to adapt to the variety of ecosystems they now successfully inhabit. While the domestic cat ancestor lived a strictly solitary life, unowned free-ranging cats today may live in multi-male/multi-female colonies in urban city centres, where they are dependent on food provided by people. Urban free-ranging cats are now more social, which has been reflected in different breeding patterns, lower infanticide, more frequent affiliative interactions in general, and different spatial groupings. This means there is a potential for domestic cat behaviour to be ‘misunderstood’. Recognising that negative impacts of free-ranging domestic cats in urban fringe areas must be mitigated, we discuss how understanding behavioural plasticity and other recently evolved traits of domestic cats may lead to management strategies that maximise health and welfare of cats, wildlife, and humans.
... Groups of free-living dogs have been found to live in social hierarchies in several studies including in Italy Cafazzo et al., 2010;Bonanni et al., 2017;Silk et al., 2019), Spain (Font, 1987), and India (Pal et al., 1998;Sen Majumder et al., 2014). Social hierarchies have also been observed in owned dogs in the United States at a day care center (Trisko and Smuts, 2015) and a dog park (Bauer and Smuts, 2007). ...
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Dogs’ remarkable success in living in a human-dominated world rests on a set of adaptations to cohabitation with humans. In this paper, I review the nature of these adaptations. They include changes in reproductive and foraging behavior from their ancestor species, wolves, which can be understood as adaptations to the change from hunting live prey to feeding on human food residues. Dogs also show several changes in social behavior which are more controversial and even somewhat paradoxical. Contrary to theories of canine domestication which view dogs as less aggressive and more cooperative than wolves, several studies show that dogs’ social interactions with conspecifics are more hierarchical and competitive than are wolves’. As scavengers rather than hunters, dogs do not need to cooperate with conspecifics the way that wolves do. But how then can we understand dogs’ willingness to cooperate with humans? I propose an integrated account of dogs’ social behavior that does not assume that dogs need to recognize the species-identity of the individuals with whom they interact. Because of the overlap in formal signals of dominance and submission between dog and human and people’s complete control over the resources dogs need, I propose that people occupy a status of “super-dominance” over dogs. This conception suggests several new lines of research which could shed light on the human-dog relationship to the benefit of both partners.
Chapter
Unsere Männchen und Weibchen beziehungsweise Männer und Frauen konnten sich zuletzt, nachdem wir uns durch vier Kapitel gekämpft haben, glücklicherweise erfolgreich paaren, und wir kamen zu der erfreulichen Erkenntnis, dass weder die Menschen noch die diversen Tierarten (mit Ausnahme vielleicht des großen Pandas, der für seine Lustlosigkeit berüchtigt ist) letztlich nur aus dem Grunde aussterben werden, weil es ihnen an sexueller Energie mangelt. Das egoistische Gen hat nämlich vorgesorgt und die diversen erfolgreichen Überlebensmaschinen mit ausreichend Liebessehnsucht und sexuellem Verlangen ausgestattet.
Chapter
In the current chapter we focus on the social relationships dogs and wolves establish with their pack mates. Dominance and affiliation are relevant features to describe the social relationships of both wolves and dogs. In both species, submissive behaviours and greeting are the best indicators of formal dominance relationships, and in general a linear hierarchy can be detected in most packs. While wolf packs may show a more consistent pattern of clear hierarchical relationships than dogs, subdominant wolves are still more willing to stand their ground to get access to resources, which is accepted by the higher-ranking wolves to some degree. In dogs, this pattern cannot be observed but instead high-ranking animals dominate resources and may escalate into aggression if lower-ranking animals do not keep their distance. In regard to affiliation, measures of proximity and affiliative rates correlate in wolves and dogs, suggesting that both can be used as indexes of bondedness, although, arguably, exchange of affiliative interactions provides a more accurate measure. Behaviours shown in the play contexts in terms of competitive vs. more gentle play reflect the social relationships the animals exhibit outside of play. In accordance, winning positions during dyadic play are exhibited more by the dominant individual in the dyad, and in general there seems little evidence of ‘fair play’ in terms of adherence to the "50:50” rule.
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Social tolerance is generally treated as a stable, species-specific characteristic. Recent research, however, has questioned this position and emphasized the importance of intraspecific variation. We investigate the temporal stability of social tolerance in four groups of sanctuary-housed chimpanzees over eight years using a commonly employed measure: experimental cofeeding tolerance. We then draw on longitudinal data on the demographic composition of each group to identify the factors associated with cofeeding tolerance. We find appreciable levels of variation in cofeeding tolerance across both groups and years that correspond closely to changes in group-level demographic composition. For example, cofeeding tolerance is lower when there are many females with young infants. These results suggest that social tolerance may be a ‘responding trait’ of chimpanzee sociality, reflecting individual-level behavioral responses to social changes. Additional, experimental research is needed to better model the causal drivers of social tolerance within and among species.
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Dominance behaviours have been collected for many groups of animals since 1922 and serve as a foundation for research on social behaviour and social structure. Despite a wealth of data from the last century of research on dominance hierarchies, these data are only rarely used for comparative insight. Here, we aim to facilitate comparative studies of the structure and function of dominance hierarchies by compiling published dominance interaction datasets from the last 100 years of work. This compiled archive includes 436 datasets from 190 studies of 367 unique groups (mean group size 13.8, s.d. = 13.4) of 135 different species, totalling over 243 000 interactions. These data are presented in an R package alongside relevant metadata and a tool for subsetting the archive based on biological or methodological criteria. In this paper, we explain how to use the archive, discuss potential limitations of the data, and reflect on best practices in publishing dominance data based on our experience in assembling this dataset. This archive will serve as an important resource for future comparative studies and will promote the development of general unifying theories of dominance in behavioural ecology that can be grounded in testing with empirical data. This article is part of the theme issue ‘The centennial of the pecking order: current state and future prospects for the study of dominance hierarchies’.
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The extant primates of Madagascar (Lemuriformes) represent the endpoints of an adaptive radiation following a single colonization event more than 50 million years ago. They have since evolved a diversity of life history traits, ecological adaptations and social systems that rivals that of all other living primates combined. Their social systems are characterized by a unique combination of traits, including the ability of adult females to dominate adult males. In fact, there is no other group of mammals in which female dominance is so widespread. Yet, recent research has indicated that there is more interspecific variation in lemur intersexual relationships than previously acknowledged. Here, we therefore review and summarize the relevant literature, quantifying the extent of sex-bias in intersexual dominance relations documented in observational and experimental studies in captivity and the wild. Female dominance is often, but not always, implemented by spontaneous male submission in the absence of female aggression and linked to female sexual maturation. We connect the available evidence to the hypotheses that have been proposed to explain the evolution of female dominance among lemurs. The occurrence of female dominance in all lemur families and the interspecific variation in its extent indicate that it has evolved soon after lemurs colonized Madagascar – presumably in response to particular ecological challenges – and that it has since been reduced in magnitude independently in some taxa. Our study contributes important comparative information on sex roles from an independent primate radiation and provides general insights into the conditions, opportunities and obstacles in the evolution of female-biased power.
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Background: Dominance is one of the most pervasive concepts in the study of wolf social behaviour but recently its validity has been questioned. For some authors, the bonds between members of wolf families are better described as parent-offspring relationships and the concept of dominance should be used just to evaluate the social dynamics of non-familial captive pack members (e.g., Mech & Cluff, 2010). However, there is a dearth of studies investigating dominance relationships and its correlates in wolf family packs. Methods: Here, we applied a combination of the most commonly used quantitative methods to evaluate the dominance relationships in a captive family pack of 19 Arctic wolves. Results: We found a significant linear and completely transitive hierarchy based on the direction of submissive behaviours and found that dominance relationships were not influenced by the competitive contexts (feeding vs. non-feeding context). A significant linear hierarchy also emerges amongst siblings once the breeding pair (the two top-ranking individuals) is removed from analyses. Furthermore, results suggest that wolves may use greeting behaviour as a formal signal of subordination. Whereas older wolves were mostly dominant over younger ones, no clear effect of sex was found. However, frequency of agonistic (submissive, dominant and aggressive) behaviours was higher between female-female and male-male dyads than female-male dyads and sex-separated linear hierarchies showed a stronger linearity than the mixed one. Furthermore, dominance status was conveyed through different behavioural categories during intra-sexual and inter-sexual interactions. Discussion: Current results highlight the importance of applying a systematic methodology considering the individuals' age and sex when evaluating the hierarchical structure of a social group. Moreover, they confirm the validity of the concept of dominance relationships in describing the social bonds within a family pack of captive wolves.
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Domesticated species are often composed of distinct populations differing in the character and strength of artificial and natural selection pressures, providing a valuable model to study adaptation. In contrast to pure-breed dogs that constitute artificially maintained inbred lines, free-ranging dogs are typically free-breeding, i.e., unrestrained in mate choice. Many traits in free-breeding dogs (FBDs) may be under similar natural and sexual selection conditions to wild canids, while relaxation of sexual selection is expected in pure-breed dogs. We used a Bayesian approach with strict false-positive control criteria to identify FST-outlier SNPs between FBDs and either European or East Asian breeds, based on 167,989 autosomal SNPs. By identifying outlier SNPs located within coding genes, we found four candidate genes under diversifying selection shared by these two comparisons. Three of them are associated with the Hedgehog (HH) signaling pathway regulating vertebrate morphogenesis. A comparison between FBDs and East Asian breeds also revealed diversifying selection on the BBS6 gene, which was earlier shown to cause snout shortening and dental crowding via disrupted HH signaling. Our results suggest that relaxation of natural and sexual selection in pure-breed dogs as opposed to FBDs could have led to mild changes in regulation of the HH signaling pathway. HH inhibits adhesion and the migration of neural crest cells from the neural tube, and minor deficits of these cells during embryonic development have been proposed as the underlying cause of “domestication syndrome.” This suggests that the process of breed formation involved the same genetic and developmental pathways as the process of domestication.
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Parent-offspring conflict theory predicts the emergence of weaning conflict between a mother and her offspring arising from skewed relatedness benefits. Empirical observations of weaning conflict have not been carried out in canids. In a field-based study on free-ranging dogs we observed that nursing/suckling bout durations decrease, proportion of mother-initiated nursing bouts decrease and mother-initiated nursing/suckling terminations increase with pup age. We identified the 7th - 13th week period of pup age as the zone of conflict between the mother and her pups, beyond which suckling solicitations cease, and before which suckling refusals are few. We also report for the first time milk theft by pups who take advantage of the presence of multiple lactating females, due to the promiscuous mating system of the dogs. This behaviour, though apparently disadvantageous for the mothers, is perhaps adaptive for the dogs in the face of high mortality and competition for resources.
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The gray wolf (Canis lupus) is a widely distributed top predator and ancestor of the domestic dog. The specific evolutionary relationships of dogs and extant wolves are controversial and have been explored with a variety of genomic approaches. However, these studies suffer from a paucity of samples from throughout the Holarctic range of the wolf. To address questions about wolf relationships to each other and dogs, we assemble and analyze a dataset of 34 canine genomes. The divergence between New and Old World wolves is the earliest branching event, and is followed by the divergence of Old World wolves and dogs, confirming that the dog was domesticated in the Old World. However, no single wolf population is more closely related to dogs, supporting the hypothesis that dogs were derived from an extinct wolf population. All extant wolves have a surprising recent common ancestry, and experienced a dramatic population decline beginning at least ~30 kya. We suggest this crisis was related to the colonization of Eurasia by modern human hunter-gatherers who competed with wolves for limited prey but also domesticated them, leading to a compensatory population expansion of dogs. We found extensive admixture between dogs and wolves, with up to 25% of Eurasian wolf genomes showing signs of dog ancestry. Dogs have influenced the recent history of wolves through admixture and vice versa, potentially enhancing adaptation. Simple scenarios of dog domestication are confounded by admixture, and studies that do not take admixture into account with specific demographic models are problematic.
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The origin and evolution of the domestic dog remains a controversial question for the scientific community, with basic aspects such as the place and date of origin, and the number of times dogs were domesticated, open to dispute. Using whole genome sequences from a total of 58 canids (12 gray wolves, 27 primitive dogs from Asia and Africa, and a collection of 19 diverse breeds from across the world), we find that dogs from southern East Asia have significantly higher genetic diversity compared to other populations, and are the most basal group relating to gray wolves, indicating an ancient origin of domestic dogs in southern East Asia 33 000 years ago. Around 15 000 years ago, a subset of ancestral dogs started migrating to the Middle East, Africa and Europe, arriving in Europe at about 10 000 years ago. One of the out of Asia lineages also migrated back to the east, creating a series of admixed populations with the endemic Asian lineages in northern China before migrating to the New World. For the first time, our study unravels an extraordinary journey that the domestic dog has traveled on earth.Cell Research advance online publication 15 December 2015; doi:10.1038/cr.2015.147.
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Dogs were the first domesticated species, originating at least 15,000 y ago from Eurasian gray wolves. Dogs today consist primarily of two specialized groups-a diverse set of nearly 400 pure breeds and a far more populous group of free-ranging animals adapted to a human commensal lifestyle (village dogs). Village dogs are more genetically diverse and geographically widespread than purebred dogs making them vital for unraveling dog population history. Using a semicustom 185,805-marker genotyping array, we conducted a large-scale survey of autosomal, mitochondrial, and Y chromosome diversity in 4,676 purebred dogs from 161 breeds and 549 village dogs from 38 countries. Geographic structure shows both isolation and gene flow have shaped genetic diversity in village dog populations. Some populations (notably those in the Neotropics and the South Pacific) are almost completely derived from European stock, whereas others are clearly admixed between indigenous and European dogs. Importantly, many populations-including those of Vietnam, India, and Egypt-show minimal evidence of European admixture. These populations exhibit a clear gradient of short-range linkage disequilibrium consistent with a Central Asian domestication origin.
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A dominance hierarchy is an important feature of the social organisation of group living animals. Although formal and/or agonistic dominance has been found in captive wolves and free-ranging dogs, applicability of the dominance concept in domestic dogs is highly debated, and quantitative data are scarce. Therefore, we investigated 7 body postures and 24 behaviours in a group of domestic dogs for their suitability as formal status indicators. The results showed that high posture, displayed in most dyadic relationships, and muzzle bite, displayed exclusively by the highest ranking dogs, qualified best as formal dominance indicators. The best formal submission indicator was body tail wag, covering most relationships, and two low postures, covering two-thirds of the relationships. In addition, both mouth lick, as included in Schenkel's active submission, and pass under head qualified as formal submission indicators but were shown almost exclusively towards the highest ranking dogs. Furthermore, a status assessment based on changes in posture displays, i.e., lowering of posture (LoP) into half-low, low, low-on-back or on-back, was the best status indicator for most relationships as it showed good coverage (91% of the dyads), a nearly linear hierarchy (h' = 0.94, p
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Dominance is one of the most pervasive and important behaviors among wolves in a pack, yet its significance in free-ranging packs has been little studied. Insights into a behavior can often be gained by examining unusual examples of it. In the High Arctic near Eureka, Nunavut, Canada, we videotaped and described an unusually prolonged and intensive behavioral bout between an adult male GrayWolf (Canis lupus) and a male member of his pack, thought to be a maturing son.With tail raised, the adult approached a male pack mate about 50 m from us and pinned and straddled this packmate repeatedly over 6.5 minutes, longer than we had ever seen in over 50 years of studying wolves. We interpreted this behavior as an extreme example of an adult wolf harassing a maturing offspring, perhaps in prelude to the offspring's dispersal.
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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).
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Biological market theory models the action of natural selection as a marketplace in which animals are viewed as traders with commodities to offer and exchange. Studies of female Old World monkeys have suggested that grooming might be employed as a commodity to be reciprocated or traded for alternative services, yet previous tests of this grooming-trade model in wild adult male chimpanzees have yielded mixed results. Here we provide the strongest test of the model to date for male chimpanzees: we use data drawn from two social groups (communities) of chimpanzees from different populations and give explicit consideration to variation in dominance hierarchy steepness, as such variation results in differing conditions for biological markets. First, analysis of data from published accounts of other chimpanzee communities, together with our own data, showed that hierarchy steepness varied considerably within and across communities and that the number of adult males in a community aged 20–30 years predicted hierarchy steepness. The two communities in which we tested predictions of the grooming-trade model lay at opposite extremes of this distribution. Second, in accord with the grooming-trade model, we found evidence that male chimpanzees trade grooming for agonistic support where hierarchies are steep (despotic) and consequent effective support is a rank-related commodity, but not where hierarchies are shallow (egalitarian). However, we also found that grooming was reciprocated regardless of hierarchy steepness. Our findings also hint at the possibility of agonistic competition, or at least exclusion, in relation to grooming opportunities compromising the free market envisioned by biological market theory. Our results build on previous findings across chimpanzee communities to emphasize the importance of reciprocal grooming exchanges among adult male chimpanzees, which can be understood in a biological markets framework if grooming by or with particular individuals is a valuable commodity.
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Mating and reproductive outcome is often determined by the simultaneous operation of different mechanisms like intra-sexual competition, mating preferences and sexual coercion. The present study investigated how social variables affected mating outcome in a pack of free-ranging dogs, a species supposed to have lost most features of the social system of wolves during domestication. We found that, although the pack comprised multiple breeding individuals, both male copulation success and female reproductive success were positively influenced by a linear combination of dominance rank, age and leadership. Our results also suggest that mate preferences affect mating outcome by reinforcing the success of most dominant individuals. In particular, during their oestrous period bitches clearly searched for the proximity of high-ranking males who displayed affiliative behaviour towards them, while they were more likely to reject the males who intimidated them. At the same time, male courting effort and male-male competition for receptive females appeared to be stronger in the presence of higher-ranking females, suggesting a male preference for dominant females. To our knowledge, these results provide the first clear evidence of social regulation of reproductive activities in domestic dogs, and suggest that some common organizing mechanisms may contribute to shape the social organization of both dogs and wolves.
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Parental care is an essential component in the life history of mammals. In group-living species, care can be provided by adults other than the parents, and such care is termed alloparental care. Alloparental care is known in a wide spectrum of species, from insects to humans. Most canids that live in stable packs demonstrate cooperative breeding, where subordinates provide care to the offspring of the dominants, without reproducing themselves. Free-ranging dogs in India have a dynamic social system and, unlike their cooperatively breeding ancestors, the grey wolves, all adults in a dog group have equal mating opportunities. This at times leads to the birth of multiple litters within an existing dog group. In this paper, we report the first field observations of alloparental care made on a dog group where a bitch provided care to her grandpups, through interactions other than suckling. The allomaternal care acted as a supplement to the care provided by the mother, and was thus beneficial to the pups.
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Movement interactions and the underlying social structure in groups have relevance across many social-living species. Collective motion of groups could be based on an "egalitarian" decision system, but in practice it is often influenced by underlying social network structures and by individual characteristics. We investigated whether dominance rank and personality traits are linked to leader and follower roles during joint motion of family dogs. We obtained high-resolution spatio-temporal GPS trajectory data (823,148 data points) from six dogs belonging to the same household and their owner during 14 30-40 min unleashed walks. We identified several features of the dogs' paths (e.g., running speed or distance from the owner) which are characteristic of a given dog. A directional correlation analysis quantifies interactions between pairs of dogs that run loops jointly. We found that dogs play the role of the leader about 50-85% of the time, i.e. the leader and follower roles in a given pair are dynamically interchangable. However, on a longer timescale tendencies to lead differ consistently. The network constructed from these loose leader-follower relations is hierarchical, and the dogs' positions in the network correlates with the age, dominance rank, trainability, controllability, and aggression measures derived from personality questionnaires. We demonstrated the possibility of determining dominance rank and personality traits of an individual based only on its logged movement data. The collective motion of dogs is influenced by underlying social network structures and by characteristics such as personality differences. Our findings could pave the way for automated animal personality and human social interaction measurements.
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Herds of ungulates, flocks of birds, swarms of insects and schools of fish move in coordinated groups. Computer models show that only one or very few animals are needed to initiate and direct movement. To investigate initiation mechanisms further, we studied two ways in which movement can be initiated in feral horses: herding, and departure from the group. We examined traits affecting the likelihood of a horse initiating movement i.e. social rank, affiliative relationships, spatial position, and social network. We also investigated whether group members join a movement in dominance rank order. Our results show that whereas herding is exclusive to alpha males, any group member may initiate movement by departure. Social bonds, the number of animals interacted with, and the spatial position were not significantly associated with movement initiation. We did not find movement initiation by departure to be exclusive to any type of individual. Instead we find evidence for a limited form of distributed leadership, with higher ranking animals being followed more often.
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Dominance hierarchies in groups of social animals can be based either on asymmetries that are important for agonistic interactions (such as body mass) or on more ‘conventional’ cues (such as age), which are respected despite having little relationship to the animal's fighting abilities. We investigated how social dominance is influenced by age and body mass in a herd of 29–39 beef cows over a 10-year period, focusing on all levels of the dominance hierarchy (individual, dyadic and group). The results demonstrate that age prevails over body mass in the structuring of the dominance network in beef cattle. At the individual level, path analysis confirmed that the dominance index of a cow was more strongly associated with her age than with her body mass. At the dyadic level, age superiority had a stronger influence on the direction of social dominance in pairs than body mass superiority. Older cows were dominant in 73.6% of those dyads studied, even when the younger cow was heavier. At the group level, the strong influence of age on dominance produced a hierarchy that was very stable and strongly transitive. Our findings show that beef cows, for the most part, do not use their physical strength to attain dominance over older, but lighter, herdmates. This results in a stable age-based hierarchy, which might serve a universally shared function that promotes the smooth functioning of the herd and/or the expression of experience by older cows. Among the theoretical models of conflict resolution, the system most closely resembles the partial bourgeois evolutionarily stable strategy.
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Agonism is common in group-living animals, shaping dominance relationships and ultimately impacting individual fitness. Rates of agonism vary considerably among taxa, however, and explaining this variation has been central in ecological models of female social relationships in primates. Early iterations of these models posited a link to diet, with more frequent agonism predicted in frugivorous species due to the presumed greater contestability of fruits relative to other food types. Although some more recent studies have suggested that dietary categories may be poor predictors of contest competition among primates, to date there have been no broad, cross-taxa comparisons of rates of female-female agonism in relation to diet. This study tests whether dietary variables do indeed predict rates of female agonism and further investigates the role of group size (i.e., number of competitors) and substrate use (i.e., degree of arboreality) on the frequency of agonism. Data from 44 wild, unprovisioned groups, including 3 strepsirhine species, 3 platyrrhines, 5 colobines, 10 cercopithecines, and 2 hominoids were analyzed using phylogenetically controlled and uncontrolled methods. Results indicate that diet does not predict agonistic rates, with trends actually being in the opposite direction than predicted for all taxa except cercopithecines. In contrast, agonistic rates are positively associated with group size and possibly degree of terrestriality. Competitor density and perhaps the risk of fighting, thus, appear more important than general diet in predicting agonism among female primates. We discuss the implications of these results for socio-ecological hypotheses.
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Existing definitions can be structural or functional, refer to roles or to agonistic behaviour, regard dominance as a property of individuals or as an attribute of dyadic encounters, concentrate on aggression or on the lack of it, and be based either on theoretical constructs or on observable behaviour. Thirteen definitions of dominance are reviewed, and their usefulness assessed with respect to their descriptive value. By virtue of its high descriptive value, the original definition of dominance by Schjelderupp-Ebbe (1922) emerged as the basis to formulate a structural definition with wide applicability and which reflects the essence of the concept: Dominance is an attribute of the pattern of repeated, agonistic interactions between two individuals, characterized by a consistent outcome in favour of the same dyad member and a default yielding response of its opponent rather than escalation. Dominance status refers to dyads while dominance rank, high or low, refers to the position in a hierarchy and, thus, depends on group composition. Dominance is a relative measure and not an absolute property of individuals. Discussion includes reference to the heritability of dominance, application of dominance to groups rather than individuals, and the role of individual recognition and memory during agonistic encounters. -from Author
Article
Dog social behaviour has been well studied, but little is known about affiliative relationships between dogs. We report a yearlong study of dominance and affiliation in 24 dogs at a dog daycare facility and provide additional details on dog relationships through long-term observations of pairs of dogs who lived together in the same household or met frequently for years. Companion dogs formed highly differentiated relationships with one another. At daycare, some dyads affiliated and displayed one-way submission (formal dominance), others affiliated without a dominance relationship (egalitarian), and the majority of dyads did not affiliate at all (agonistic or non-interactive). The dogs in household environments showed formal and egalitarian relationships, and two dyads exchanged two-way agonism without submission (unresolved). Sex influenced the types of relationships dogs formed, with mixed sex dyads more likely to affiliate and less likely to exhibit dominance than same-sex pairs. Dominance influenced the nature of affiliation in relationships; egalitarian dyads were more likely to play and showed more equitable gentle affiliation. Gentle affiliation was reciprocal in the group as a whole, but it was highly skewed in many dyads, especially those with dominance relationships. Gentle affiliation was usually, but not always, directed up the hierarchy. Certain dyads affiliated at much higher rates than others, indicating that the dogs formed friendships. Most friends were mixed sex and/or egalitarian pairs, but friendships occurred in all of the sex class/dominance combinations. Long-term observations demonstrated how dyadic relationships can change over time. Such highly differentiated relationships suggest significant social complexity in dogs.
Article
This dissertation examines dominance, play, affiliation and social preferences in a group of 24 domestic dogs that socialize regularly at a dog daycare facility. In Chapter 1, we analyzed the frequencies and directions of aggression, submission, and dominance displays. The distribution of submission and aggression resulted in a significantly linear hierarchy in the group, and submission was the best indicator of dominance relationships. Age was significantly correlated with dominance rank with older dogs out-ranking younger dogs. Muzzle-licking met most of the criteria for a formal display of submission in dogs, but was displayed in only 18% of relationships. Only 29% of all possible pairs had discernable dominance relationships. In Chapter 2, we examined the relationship between agonism, play and affiliation. Twenty-two percent of all possible pairs had known dominance relationships and also exchanged friendly behaviors (formal relationships), 21% of all pairs exchanged friendly behavior but had no discernable dominance relationship (egalitarian relationships), 50% of all pairs were never observed exchanging friendly or agonistic behaviors (non-interactive relationships), and 7% of pairs had known dominance relationships but did not exchange friendly behavior (agonistic relationships). Friendly behavior was much more frequent than agonistic behavior, and we found a complex association between the two. Egalitarian relationships as well as play and affiliation were more common between males and females than between same-sex pairs. Relationship affinity (an index combining play and affiliation) did not significantly differ in formal versus egalitarian relationships, but the latter were significantly more equitable and playful. In Chapter 3, we investigated patterns of interventions during dyadic play. Interveners directed either (1) a playful behavior at one of the dogs (the target), (2) an affiliative behavior at the target, or rarely, (3) an aggressive behavior at the target. Individual rank did not influence individual interventions rates. Rank relationships between interveners, targets and non-targets did not influence playful interventions. Dogs tended to target higher-ranking dogs during affiliative interventions and target lower-ranking dogs during aggressive interventions, but the latter were too infrequent to apply statistical analyses. Dogs tended to target their preferred partners (“friends”) during play more than support them.
Article
We here respond to the claim by Schilder and colleagues (Schilder, M. B. H., Vinke, C. M., van der Borg, J. A. M., 2014. Dominance in domestic dogs revisited: Useful habit and useful construct? J. Vet. Behav.: Clin. App. Res. 9, 184-191) that dominance is a useful construct in the interpretation of companion dog behavior. We first make the distinction between the well-established use of the dominance framework in the ethology of wild species, and its more contentious use in the domestic dog as a character trait and as a descriptor of motivation. By evaluating recent studies of canine “personality” (individual differences in behavior that are consistent across time and context), we conclude that there is no evidence that dominance is a character trait of individual dogs, but rather that it is a property of relationships, that can arise due to asymmetries in any one of at least 3 distinct personality traits. We question whether concepts derived from wolf behavior have much utility in interpreting the behavior of domestic dogs because recent studies of groups of free-ranging dogs confirm that the dog has lost 3 traits key to the social organization of the gray wolf, namely coordinated group hunting, reproductive suppression, and provisioning of cubs by nonreproducing relatives. We further question whether studies of free-ranging dogs, which routinely compete for physical resources, provide an appropriate framework for interpreting the behavior of companion dogs, which generally do not. We then reinterpret Schenkel's “active submission” posture as primarily affiliative and an indicator of the dependence of younger, inexperienced dogs on the older members of their social group. By reviewing the key literature on the cognitive abilities of domestic dogs and other social Carnivora, we demonstrate that the primate-based “Utrecht School” model of dominance makes assumptions that are invalid for domestic dogs, because the overwhelming balance of evidence indicates that relationships among social Carnivora are based on noncognitive mechanisms. We conclude by examining the implications of Schilder and colleagues' model for the management of relationships between dogs and their owners.
Article
Few studies on dog-dog interactions exist relative to those on dog-human interactions. Despite using many action patterns derived from fighting and hunting, conspecific social play can be distinguished by its self-restraint, use of play signals, self-handicapping, and role reversals. However, in play between adult dogs, older/larger and more dominant dogs rarely self-handicapped and typically adopted 'winning' roles more than 50% of the time; play in pairs of littermates was similarly asymmetrical. Most dog play is dyadic, but in both puppies and adults, third parties sometimes intervene to reap various advantages. Dyadic rank asymmetries have been documented through pair-wise competition over resources, but analysis in dog groups of the same formal dominance signals used by wolves (such as high posture by dominants and muzzle-licking by subordinates) produced more consistent results, including the presence of linear dominance hierarchies. However, at a dog daycare center, over two-thirds of the dog dyads failed to exhibit formal dominance signals, including dyads that showed high affiliation. Multiple studies of dogs interacting in dog-park-like settings reported the absence of biting, perhaps in part because dogs reconcile after conflicts, but maybe also because aggressive dogs are leashed or stay home. Both adult dogs and littermates exhibited clear affiliative partner preferences, but, aside from the play context, dog-dog friendship has hardly been studied.
Article
Although a large part of the global domestic dog population is free-ranging and free-breeding, knowledge of genetic diversity in these free-breeding dogs (FBDs) and their ancestry relations to pure-breed dogs is limited, and the indigenous status of FBDs in Asia is still uncertain. We analyse genome-wide SNP variability of FBDs across Eurasia, and show that they display weak genetic structure and are genetically distinct from pure-breed dogs rather than constituting an admixture of breeds. Our results suggest that modern European breeds originated locally from European FBDs. East Asian and Arctic breeds show closest affinity to East Asian FBDs, and they both represent the earliest branching lineages in the phylogeny of extant Eurasian dogs. Our biogeographic reconstruction of ancestral distributions indicates a gradual westward expansion of East Asian indigenous dogs to the Middle East and Europe through Central and West Asia, providing evidence for a major expansion that shaped the patterns of genetic differentiation in modern dogs. This expansion was probably secondary and could have led to the replacement of earlier resident populations in Western Eurasia. This could explain why earlier studies based on modern DNA suggest East Asia as the region of dog origin, while ancient DNA and archaeological data point to Western Eurasia.
Article
This book provides an up-to-date description of the behavioural biology of dogs. It is written for students of animal behaviour or veterinary medicine at advanced levels and dog owners. This book is divided into 4 parts and 14 chapters. The first part (chapters 1-3) focuses on the evolution and development of the dog. The second part (chapters 4-8) deals with the basic aspects of animal behaviour with particular emphasis on dogs. The third part (chapters 9-12) places the modern dog in its present ecological framework in the niche of human coexistence. A broad overview of the behavioural aspects of living close to humans is given. The fourth part (chapters 13 and 14) focuses on behavioural problems, their prevention and cure.
Article
This chapter examines the population of different genetic structures of dogs. It identifies the genetic and phenotypic distinctiveness of modern breed dogs and free-breeding dog populations. It provides an answer to what one might want to conserve and why. It also summarizes the current state of dog diversity.
Article
We investigated the extent to which dominance relationships, as described for feral dogs and wolves, applied to a group of 24 neutered companion dogs at a dog daycare facility. Similar to other studies of dogs and wolves, we found significant linear dominance hierarchies based on highly unidirectional displays of submission and aggression. Submission was the most frequent, unidirectional and linear type of agonistic behaviour and, therefore, a better indicator of status than aggression or dominance displays. Aggression was low intensity, consisting mainly of ritualized threats with no physical contact, and conflicts involving physical contact were never injurious. Older dogs out-ranked younger dogs, but size was unrelated to dominance rank. Dominance relationships were more often expressed in same-sex dyads than between males and females. The coverage of dominance relationships in the daycare group was low compared to that reported for sexually intact dogs and wolves, which was probably a result of reduced competition due to neutering and other human influences. In many dyads dogs never exchanged agonistic behaviours, but bi-directional relationships were rare, and most dogs formed some dominance relationships with other dogs. Except for their low coverage, muzzle licks met the criteria for a formal display of submission. Our results suggest that dominance remains a robust component of domestic dog behaviour even when humans significantly reduce the potential for resource competition. The possible proximate benefits of dominance relationships for dogs are discussed.
Article
We investigated the effects of sex, age, season and competitive context on the intergroup agonistic behaviour of free-ranging dogs (Canis familiaris). Data were collected in different places to record competitive cooperative behavior during intergroup conflicts. Observations of 21 free-ranging dogs belonging to four neighbouring groups were made in Katwa town, India. Throughout the 12-month study period, 85 % of all intergroup agonistic interactions recorded were aggressive and 15 % submissive. Intergroup aggressive interactions were more frequent during the late monsoon months when the females were in oestrus, while submissive interactions reached a peak during the winter months when the females were lactating. Adult dogs, particularly males, displayed a higher rate of aggressive behaviour than other age classes, whereas juvenile dogs, particularly males, displayed the highest rate of submissive behaviour.Male dogs were observed to perform more agonistic behaviours in mating contexts and at the boundaries of their territories, whereas female dogs displayed more agonistic behaviours in feeding contexts and in the vicinity of the den. Both aggressive and submissive patterns displayed by the dogs varied with the competitive contexts. The most frequently observed category of aggressive behaviour was ‘barking, growling and snarling’ and submissive behavioural patterns were displayed frequently by ‘lips retracted in a submissive grin’. The striking feature of this study was that in most cases, more than one dog participated in aggressive conflicts. Such cooperative defense predominantly occurred at the boundaries of territory. Group home range size was largest during the late monsoon months and during the winter months.
Chapter
Domestication is thought to have reduced dogs' ability to form organised packs with conspecifics. Here, we investigated the social organisation of a population of free-ranging dogs living in a suburban area of Rome. Almost all animals were not socialised to humans, although they subsisted on food provided by people, and lived in stable social groups whose organisation appeared more similar to that of wolves than previously reported. In all groups studied, a linear dominance hierarchy could be detected based on the directionality of submissive behaviour. Social regulation of reproductive activities was also observed. Affiliative relationships appeared to promote both leader-follower relationships and cooperation in conflicts against stranger packs. Larger packs outcompeted smaller ones in contests for food and space. A reduction in both cooperative breeding and territorial aggression relative to wolves can be reasonably interpreted as an adaptation to the domestic environment. We suggest that dogs are more likely to form stable packs when they are not socialised to humans and can subsist on abundant and clumped food resources.
Chapter
Overview In this chapter we outline proximate processes that favour group formation and lead to the emergence of social structure in mammalian societies, particularly complex societies. We operationally define a mammalian society as complex if its social structure includes social coalitions, social alliances or social queues – well known from primates, elephants and cetaceans but also present in, for instance, some carnivores, bats, rodents and ungulates. We consider how social structure can lead to a disparity in the benefits and costs acquired by group members, and how this leads to conflicts of interest between them. We detail the social and reproductive tactics that individuals use when conflicts arise, and consider the fitness consequences associated with these tactics. We illustrate most key points using observational studies of free-ranging mammals, because experimental studies are rare, and we draw examples from a broad range of social systems and mammalian orders. Introduction How do complex societies emerge from a life in groups? Living in groups inevitably results in conflicts of interest between group members. The specific forms of these conflicts are likely to affect the strategies to cope with them. Not only will the details of these strategies shape the social relationships we can observe, they may be the consequences of evolutionary processes, and are likely to have resulted in the social complexity described for many mammalian societies.
Article
Negative impacts from the presence of domestic animals pose particular issues for biodiversity conservation as they are intimately tied to the economic, social and political values of local people, requiring interdisciplinary cooperation for successful outcomes. Despite domestic dogs being widespread there is little information on the scale and scope of any conservation problems they may cause. Dog management is already carried out by human health and welfare groups in order to improve welfare and reduce disease spread, primarily rabies. By reviewing information about interactions between dogs and wildlife, this paper aims to provide a clear summary of current knowledge and facilitate interdisciplinary collaboration between conservation biologists and other experts.Data from dog population and human population studies indicate that the global domestic dog population abundance is over 700 million. Studies on interactions between free-roaming dogs and wildlife were gathered from searches of seven online databases and other sources. In total, 69 peer-reviewed studies were found. The wildlife taxon mainly studied was mammals (78%) and the main interaction recorded was predation by domestic dogs, followed by disease transmission, wildlife disturbance, hybridization and predation of dogs by wild carnivores. Conservation issues with domestic dogs were recorded from around the world, both on islands and continents. Suggestions of solutions were limited, or not offered, beyond extermination which, given the close relationship between local people and dogs, may not often be appropriate. We propose some steps that will aid cooperation between conservationists and other sectors and enhance the effectiveness of conservation activities.
Article
Dominance hierarchies were studied in 11 herds of domestic horses and ponies (Equus caballus). A paired feeding test was utilized to establish the dominance—subordination relationship between each pair of animals in a herd. Aggressive actions, threats, bites, kicks and chases were also recorded. In small herds linear hierarchies were formed, but in large herds triangular relationships were observed. Aggression was correlated with dominance rank. Body weight, but not age, appear to affect rank in the equine hierarchy. Juvenile horses were more likely to share feed with each other than were adult horses and were usually subordinate to adult horses. The daughters of a dominant mare were dominant within their own herds.
Article
Social organization of Canis lupus is characterised by strong pairbond associations. Groups may consist of a mating couple and thier remaining offspring or of an association of potentially reproductive adults. When a pack consists of several adults, intrasexual mating competition and intersexual partner preference are expected to play an important role in the establishment of sexual relationships. Data from the wild show that as a rule only one female in a pack gives birth. Female suppression is assumed to prevent the other pack members from breeding. Together with a general rise in frequency of (sexuo-affiliative) interactions the authors observed an increase in general aggression and in the frequency of interventions during the mating season. Separative interventions were observed predominantly in males and were directed against male-female sexual interactions, while such interventions by females were less apparent. Males showed a high frequency of intrasexual aggression but only during the mating season. Females showed less intrasexual aggression, and instead, showed a high level of intrasexual dominance display, especially the alpha-female, and they did so both in and outside the mating season. Males tended to intervene in especially those intersexual contacts in which their own preferred female was involved, whereas the intolerance of the alpha-female was more general. Male competition was comparatively more context-related while female competition took the form of unprovoked hostility. -from Authors
Article
Strong pair-bonding is typical for canids. In wolf packs consisting of several adult males and females, sexual interests may clash during the mating season. We expect that not only dominance-subordinance relationships but also partner preferences play a prominent role in the establishment of pair bonds in wolves. The objective of our study is to disentangle male and female components in the establishment of sexual relationships, and, in particular, the influence of partner preferences. A first-approach model suggests that males will attempt to maximize the number of fertilizations, whereas females will be selective in partner choice. We therefore determined behavioural measures of partner preference for each sex; namely 'Following sexually' in males and 'Presenting actively' in females. Matings corresponded more to the male than the female preferences. Males initiated courtship, whereas females influenced pair-bonding more by proceptive behaviour and by the rejection of male courtship. Whereas the dominant males focused more on one preferred female at a time, and might eventually switch and direct their preference to another female, the dominant females, and particularly the alpha female, spread their sexual interests over several males and associate with more than one male at a time. The ultimate reason for this might be that, in this way, a female promotes care-giving towards herself and her offspring by creating a 'paternity illusion' in those males.
Article
We analyzed the leadership behavior of breeding and nonbreeding gray wolves (Canis lupus) in three packs during winter in 1997-1999. Scent-marking, frontal leadership (time and frequency in the lead while traveling), initiation of activity, and nonfrontal leadership were recorded during 499 h of ground-based observations in Yellowstone National Park. All observed scent-marking (N=158) was done by breeding wolves, primarily dominant individuals. Dominant breeding pairs provided most leadership, consistent with a trend in social mammals for leadership to correlate with dominance. Dominant breeding wolves led traveling packs during 64% of recorded behavior bouts (N=591) and 71% of observed travel time (N=64 h). During travel, breeding males and females led packs approximately equally, which probably reflects high parental investment by both breeding male and female wolves. Newly initiated behaviors (N=104) were prompted almost 3 times more often by dominant breeders (70%) than by nonbreeders (25%). Dominant breeding females initiated pack activities almost 4 times more often than subordinate breeding females (30 vs. 8 times). Although one subordinate breeding female led more often than individual nonbreeders in one pack in one season, more commonly this was not the case. In 12 cases breeding wolves exhibited nonfrontal leadership. Among subordinate wolves, leadership behavior was observed in subordinate breeding females and other individuals just prior to their dispersal from natal packs. Subordinate wolves were more often found leading packs that were large and contained many subordinate adults.
Article
Consensus decisions about the nature and timing of group activities allow animals to maintain group cohesiveness, but also entail costs because individuals often differ with respect to their optimal activity budgets. Two mechanisms whereby animals reach a consensus include ‘consistent leadership’, in which a single dominant individual makes the decision, and ‘variable leadership’ in which several group members contribute to the decision outcome. Sharing of consensus decisions is expected to reduce consensus costs to most group members. Both patterns are thought to emerge from the complexity of social relationships of group members. We investigated the distribution of leadership during group departures in two packs of free-ranging dogs, Canis lupus familiaris, and tested how its distribution between individuals was affected by dominance rank-related affiliative and agonistic relationships. Although leadership was not entirely concentrated on a single group member, both packs had a limited number of habitual leaders. In the largest pack, the pattern of leadership changed from ‘variable’ to nearly ‘consistent’ after its size had shrunk. Habitual leaders were usually old and high-ranking individuals. However, high-ranking dogs that received affiliative submissions in greeting ceremonies were more likely to lead than dominant dogs receiving submissions only in agonistic contexts. During resting times, habitual followers associated more closely with habitual leaders than with other followers. These results suggest that in social species collective movements may arise from the effort of subordinates to maintain close proximity with specific valuable social partners.
Article
The term "dominance" is widely used in the academic and popular literature on the behavior of domestic dogs, especially in the context of aggression. Although dominance is correctly a property of relationships, it has been erroneously used to describe a supposed trait of individual dogs, even though there is little evidence that such a trait exists. When used correctly to describe a relationship between 2 individuals, it tends to be misapplied as a motivation for social interactions, rather than simply a quality of that relationship. Hence, it is commonly suggested that a desire 'to be dominant' actually drives behavior, especially aggression, in the domestic dog. By contrast, many recent studies of wolf packs have questioned whether there is any direct correspondence between dominance within a relationship and agonistic behavior, and in contrast to wolves, hierarchical social structures have little relationship with reproductive behavior in feral dog packs. Nor do the exchanges of aggressive and submissive behavior in feral dogs, originally published by S. K. Pal and coworkers, fit the pattern predicted from wolf behavior, especially the submissive behavior observed between members of different packs. In the present study of a freely interacting group of neutered male domestic dogs, pairwise relationships were evident, but no overall hierarchy could be detected. Since there seems to be little empirical basis for wolf-type dominance hierarchies in dogs, the authors have examined alternative constructs. Parker's Resource Holding Potential (RHP) appears to be less useful when applied to domestic dogs than to other species, although it has the advantage of incorporating the concept of subjective resource value (V) as a factor influencing whether or not conflicts are escalated. The authors propose that associative learning, combined with V, can provide more parsimonious explanations for agonistic behavior in dogs than can the traditional concept of dominance.
Article
We studied the behavioural ecological characteristics of free-roaming dogs (Canis familiaris) in four Ethiopian villages via observational surveys. The Ethiopian village dogs surveyed in this study have similar characteristics to other free-roaming dog populations in the world: (1) they are almost entirely unrestrained, (2) there is a male-skewed sex ratio in the adult population, (3) the majority appear not to be owned (or at least not declared so) and (4) many of them are found around people's dwellings.
Article
Teeth-baring in a large captive rhesus monkey group (Macaca mulatta) was observed over a 30-month period. Its directional consistency among adults was significantly higher than that of aggression. The unidirectionality was so extreme that the facial display must be seen as a formal status indicator; ie, a signal of which the direction is independent of short-term contextual variation. As such, it seems adapted for communication about the state of the relationship. Formal dominance relationships among adults could be arranged in a hierarchy which approached perfect linearity. Focal observations demonstrated that teeth-baring was associated with withdrawal. It was uncommon among foraging monkeys, perhaps because dominant animals paid less attention to their subordinates in this context. The speed of rank acquisition by young females, in terms of received teeth-baring, was highest among peers and lowest against the group's old matriarchs. The age at which dominance over unrelated adult females was achieved correlated negatively with the amount of affiliative contact with these females. This translates into a positive correlation between bonding and rank establishment, indicating that dominance processes may be indistinguishable from social integration.
Article
Social conflict is defined operationally as occurring when the behavior of two (or more) individuals indicates that their motivational priorities are incompatible: they seek the same thing of different things, and both cannot be satisfied. Social dominance is defined as consistent winning at points of social conflict, regardless of the tactic used. Four problems generated by many current uses of the social dominance concept are critically reviewed here. (1) Dominance is sometimes equated with and is sometimes operationally defined as priority of access to resources. It is argued that dominance functions to resolve many kinds of social conflict, and not just those involving resources. (2) A tendency to describe all conflict resolution by using the dominance/subordination paradigm obstructs consideration of other relationships, specifically egalitarian ones. Egalitarian relationships are defined. (3) A Tendency to link dominance and aggression causes non-aggressive patterns of dominance(e.g., passive refusa...