Domestication constrains the ability of dogs to convey emotions via facial expressions in comparison to their wolf ancestors

Dogs (Canis lupus familiaris) are the domestically bred descendant of wolves (Canis lupus). However, selective breeding has profoundly altered facial morphologies of dogs compared to their wolf ancestors. We demonstrate that these morphological differences limit the abilities of dogs to successfully produce the same affective facial expressions as wolves. We decoded facial movements of captive wolves during social interactions involving nine separate affective states. We used linear discriminant analyses to predict affective states based on combinations of facial movements. The resulting confusion matrix demonstrates that specific combinations of facial movements predict nine distinct affective states in wolves; the first assessment of this many affective facial expressions in wolves. However, comparative analyses with kennelled rescue dogs revealed reduced ability to predict affective states. Critically, there was a very low predictive power for specific affective states, with confusion occurring between negative and positive states, such as Friendly and Fear. We show that the varying facial morphologies of dogs (specifically non-wolf-like morphologies) limit their ability to produce the same range of affective facial expressions as wolves. Confusion among positive and negative states could be detrimental to human-dog interactions, although our analyses also suggest dogs likely use vocalisations to compensate for limitations in facial communication.

Order stability via Fröhlich condensation in bio, eco, and social systems: The quantum-like approach

Stability of social and behavioural order in biological, ecological, and social systems is modelled within the formalism of the Fröhlich condensation. The latter is a high temperature analogue of the Bose-Einstein condensation and stability is approached via intensive pumping of energy into a system interacting with a bath. We start with the review of this formalism considering nonequilibrium thermodynamic and quantum frameworks. Although Fröhlich applied this formalism to bio-systems and the physical energy flows (electromagnetic, chemical, vibrational), he pointed out on the possibility to apply it to wider class of systems. We realize this program by using quantum-like modelling in combination with the information approach to biological and social systems, by treating them as information processors and introducing the notion of social energy (with its versions, as, e.g., social and behavioural energy). This formalism is applied to modelling of social stability in the modern open society characterized by powerful flows of information and huge information reservoir based on internet, including the variety of social networks. Then, it is applied to modelling of coherent behaviour in herds and flocks with the illustrative example of wolf packs. The essence of the paper is extracting conditions for the Fröhlich condensation and reformulating them in the purely information framework.

Heads and Tails: An Analysis of Visual Signals in Cats, Felis catus

Simple Summary

Communication between individuals of the same species is essential in their interactions to regulate their proximities and distances. Communication includes exchanges of more or less complex visual signals. We attempt to decipher the most significant features of a visual configuration involving the combination of tail and ear positions in interactions between cats. Although the tail is a conspicuous feature for human observers, we demonstrate that ear positions of the cats in dyadic interactions with other cats are the best predictor of the outcomes of these interactions. However, in cat–human interactions, the cat most often approached with its tail up prior to rubbing itself against the human. The results are important for a better understanding of cats’ perceptions of humans, and will help to promote cat welfare.

Abstract

Visual communication involves specific signals. These include the different positions of mobile body elements. We analyzed visual configurations in cats that involve ears and the tail. We aimed at deciphering which features of these configurations were the most important in cats’ interactions with other cats and with humans. We observed a total of 254 cat–cat interactions within a sample of 29 cats, during a total of 100 h of observation scheduled with the “Behavioral dependent onset of sampling” method and using the “All occurences” sampling method. In addition, we sampled 10 interactions between cats and humans. In cat–cat interactions, we noted the positions of ears and tail of both protagonists, as well as the outcome of the interaction, which was either positive/neutral or negative. In a great majority of the 254 interactions sampled, both cats held their tail down. On the contrary, ear position was a critical element in predicting the outcome. When both partners held their ears erect, the outcome was significantly positive, such as rubbing or close proximity. In all other cases of the position of ears in both cats, the outcome was negative, with increased distance of the partners. Although the tail did not seem to play a significant role in visual configurations in cat interactions, the “tail-up” display was important when a cat approached a human being. In the vast majority of cases the cat rubbed itself on a human’s leg(s). Thus, we may conclude that the presence of a human has a specific meaning in the cat’s world, probably as the result of a long period of commensalism. It is important for pet owners to understand the signals that cats use with other cats and with humans in order to promote the welfare of cats.

Comparative morphometric study of the mimic facial muscles of brachycephalic and dolichocephalic dogs

Excessive breeding of dogs has led to a disadvantageous morphology in some breeds, for example extreme brachycephaly, which is responsible for many health issues. We hypothesize that alterations of the mimic muscular system are present in brachycephalic dogs and could contribute to behavioural problems due to a restricted mimic display. Therefore, the purpose of this paper was to compare the mimic muscular systems of brachycephalic with dolichocephalic dogs. Mimic muscles were measured and set in ratio to measurements of the head and calculated indices. When bringing the length of the muscles m(x) in proportion to the length of the head, highly significant differences (p < .0001) and significant difference (p < .05) were found in all but two of the examined muscles. Calculations of the m(x) divided by the cranial index and the square index showed significant differences for all muscles. For example, the musculus (m.) levator nasolabialis was morphologically different from the one of dolichocephalic dogs. Muscle fibres of the m. levator nasolabialis were localized in the fold over the nasal bridge of brachycephalic dogs. The raphe of the m. orbicularis oris was not always apparent in brachycephalic dogs. The proportions of the muscle lengths and the length of the eye slots to the size of the skull have shifted considerably in brachycephalic dogs. We conclude that many alterations contribute to the strong shift in the proportions of the head of brachycephalic dogs versus that of dolichocephalic dogs. Our findings suggest that brachycephalic dogs have reduced mimic skills that can lead to ambiguous communication.

Evaluation of companion animal behavior knowledge among first-year veterinary students before and after an introductory animal behavior course

OBJECTIVE

To survey first-year veterinary students' knowledge of companion animal (dog, cat, and horse) behavior and popular-culture (ie, pop-culture) behavior myths related to animal body language, motivations, and learning prior to participation in an introductory animal behavior course; evaluate potential associations between sources of prior behavior knowledge and knowledge on the preclass survey; and determine whether postclass scores on the same survey were predictive of final examination score for the behavior class.

SAMPLE

156 first-year veterinary students.

PROCEDURES

Students were invited to participate in an anonymous electronic survey before and after a semester-long, 2-credit introductory animal behavior course. Demographic features, self-assessed animal behavior knowledge, and sources of prior behavior knowledge were evaluated as predictors of preclass survey knowledge scores. Postclass survey knowledge scores were evaluated for association with final examination scores as a measure of validity.

RESULTS

Preclass knowledge scores were low (mean ± SD, 49 ± 12.7%; n = 152). Reporting peer-reviewed journal articles as a source of incoming knowledge predicted 9% higher scores, whereas reporting magazines or online pop-culture articles as a source of incoming knowledge predicted 7.6% lower scores for preclass behavior knowledge, compared with scores for students not citing those respective sources. Companion animal ownership was not associated with preclass survey knowledge scores. Postclass knowledge scores were substantially improved (mean ± SD, 84.3 ± 8%) and predictive of final examination scores.

CONCLUSIONS AND CLINICAL RELEVANCE

Results indicated a profound deficit of behavior knowledge among veterinary students at the start of their curriculum. Students graduating from veterinary institutions without a comprehensive behavior course may be at a disadvantage for day 1 competency in addressing animal behavior problems.

Brain gyrification in wild and domestic canids: Has domestication changed the gyrification index in domestic dogs?

Over the last 15 years, research on canid cognition has revealed that domestic dogs possess a surprising array of complex sociocognitive skills pointing to the possibility that the domestication process might have uniquely altered their brains; however, we know very little about how evolutionary processes (natural or artificial) might have modified underlying neural structure to support species-specific behaviors. Evaluating the degree of cortical folding (i.e., gyrification) within canids may prove useful, as this parameter is linked to functional variation of the cerebral cortex. Using quantitative magnetic resonance imaging to investigate the impact of domestication on the canine cortical surface, we compared the gyrification index (GI) in 19 carnivore species, including six wild canid and 13 domestic dog individuals. We also explored correlations between global and local GI with brain mass, cortical thickness, white and gray matter volume and surface area. Our results indicated that GI values for domestic dogs are largely consistent with what would be expected for a canid of their given brain mass, although more variable than that observed in wild canids. We also found that GI in canids is positively correlated with cortical surface area, cortical thickness and total cortical gray matter volumes. While we found no evidence of global differences in GI between domestic and wild canids, certain regional differences in gyrification were observed.

Masculinity, femininity, and leadership: Taking a closer look at the alpha female

An extensive review and textual analysis of the academic and popular literature of the human alpha female was conducted to examine the social construction and expression of the alpha female identity in a small non-random sample of North American women (N = 398). This review revealed 2 predominant alpha female representations in the literature-one more masculine versus one more feminine-and 21 alpha female variables. In this sample of women, the "alpha female" was found to be a recognized socially constructed female identity. Univariate analysis revealed positive and highly significant differences in self-reported mean scores between alpha (N = 94) and non-alpha (N = 304) females for 10 variables including, masculine traits, leadership, strength, low introversion, self-esteem, life satisfaction, sexual experience, initiates sex, enjoys sex and playing a dominant role in sexual encounters, with alpha females scoring higher than non-alphas. The measure of masculine traits was identified as the only predictor of alpha female status as per the multiple regression model. Interestingly, both alpha and non-alpha women scored the same for the measure of feminine traits. Further, both groups scored higher for feminine traits than masculine traits. The results also revealed that neither social dominance nor sexual dominance were predictors of alpha female status which challenge academic and popularized representations of this identity. The results suggest that although the alpha female is often regarded as an exceptional and, at times, an exoticized form of femininity, like other femininities, her identity is marked by contradictions and tensions.

Helping Pet Owners Change Pet Behaviors: An Overview of the Science

The predominant approach to training dogs and modifying their behavior has been steeped in antiquated theories of dominance and pack leadership that are not based in scientific evidence. Animals learn best through associative and consequential interactions. Using the most current evidence-based techniques, while acknowledging that each pet is an individual, results in more effective behavior modification.

Dominance relationships in a family pack of captive arctic wolves (Canis lupus arctos): the influence of competition for food, age and sex

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.

Vocalizations in wild canids and possible effects of domestication

On the basis of spectrographic evidence it has been possible to identify twelve basic vocal sound types of canid species. Vocalizations may be mixed either by successive emission of two or more sound types, by superimposition of these sounds, or by a combination of these two forms. The same basic sound type may differ among canid species along the dimensions of sound duration, separation time between consecutive sounds, principle frequencies, cyclicity, and context. Developmental data indicate that domestic dogs first begin to mix sounds by successive sound emissions at about 10 days of age and later by superimposition between 2 and 3 weeks of age. The frequency of occurence of the basic sound types in different contexts varied between species but not within species. The possible effects of domestication on canid vocalizations are discussed.

Use of experimenter-given cues in dogs

Since the observations of O. Pfungst the use of human-provided cues by animals has been well-known in the behavioural sciences ("Clever Hans effect"). It has recently been shown that rhesus monkeys (Macaca mulatta) are unable to use the direction of gazing by the experimenter as a cue for finding food, although after some training they learned to respond to pointing by hand. Direction of gaze is used by chimpanzees, however. Dogs (Canis familiaris) are believed to be sensitive to human gestural communication but their ability has never been formally tested. In three experiments we examined whether dogs can respond to cues given by humans. We found that dogs are able to utilize pointing, bowing, nodding, head-turning and glancing gestures of humans as cues for finding hidden food. Dogs were also able to generalize from one person (owner) to another familiar person (experimenter) in using the same gestures as cues. Baseline trials were run to test the possibility that odour cues alone could be responsible for the dogs' performance. During training individual performance showed limited variability, probably because some dogs already "knew" some of the cues from their earlier experiences with humans. We suggest that the phenomenon of dogs responding to cues given by humans is better analysed as a case of interspecific communication than in terms of discrimination learning.

Human ethology: concepts and implications for the sciences of man

Human ethology is defined as the biology of human behavior. The methods it employs and the questions it poses are elaborations of those generally used in the various fields of biology, but especially adapted to the study of man. Observation and experimentation in the natural and seminatural setting as well as the comparative method derived from morphology play important roles in human ethology, and the exploration of phylogenetic adaptations constitutes one of its focal interests. On the basis of observations on experientially deprived and nondeprived children, comparative primate and animal behavior studies, and cross-cultural investigations, certain universal phylogenetic adaptations (in terms of fixed action patterns, innate releasing mechanisms, releasers, innate motivating mechanisms, and innate learning dispositions) have been found to occur. However, human ethology does not restrict itself to the investigation of phylogenetic adaptations. The question as to how a behavior pattern contributes to survival can be posed with respect to cultural patterns as well. Similar selection pressures have shaped both culturally and phylogenetically evolved patterns. Through cross-cultural studies a number of universal social interaction strategies have been discovered.

A comparison of problem-solving and spatial orientation in the wolf (Canis lupus) and dog (Canis familiaris)

In this study I tested Benson Ginsburg's theory that dogs should show diminished ability, compared to wolves, in orienting in three-dimensional space and manipulating objects sequentially. Dogs of all ages and juvenile wolves should do poorly on these measures, but at some time before sexual maturity, the juvenile wolves should begin improving to the level of adult wolves. Two adult and seven juvenile wolves were compared with 40 adult German shepherds. The initial task was to pull a single rope suspended from the ceiling; complexity was increased by the addition of ropes and by changing spatial configurations. Adult wolf performance was consistently successful across all tests and requirements. Juvenile wolves had little difficulty with one and two rope tests, but did more poorly in the three rope tests. The behavior of the dogs grouped into four profiles (# of dogs): non-responders (6), one rope (15), two rope (14), and three rope responders (5).

Context modulates signal meaning in primate communication

A central issue in the evolution of social complexity and the evolution of communication concerns the capacity to communicate about increasingly abstract objects and concepts. Many animals can communicate about immediate behavior, but to date, none have been reported to communicate about behavior during future interactions. In this study, we show that a special, unidirectional, cost-free dominance-related signal used by monkeys (pigtailed macaques: Macaca nemestrina) means submission (immediate behavior) or subordination (pattern of behavior) depending on the context of usage. We hypothesize that to decrease receiver uncertainty that the signal object is subordination, senders shift contextual usage from the conflict context, where the signal evolved, to a peaceful one, in which submission is unwarranted. We predict and find that deceasing receiver uncertainty through peaceful signal exchange facilitates the development of higher quality social relationships: Individuals exchanging the peaceful variant groom and reconcile more frequently and fight less frequently than individuals exchanging signals only in the conflict context or no signals. We rule out alternative hypotheses, including an underlying reciprocity rule, temperament, and proximity effects. Our results suggest that primates can communicate about behavioral patterns when these concern relationship rules. The invention of signals decreasing uncertainty about relationship state is likely to have been critical for the evolution of social complexity and to the emergence of robust power structures that feed down to influence rapidly changing individual behavior.

Encoding power in communication networks

In animal societies, conflicts can be resolved by combatants or through third-party intervention. In gregarious species, conflicts among pairs can spread to involve multiple individuals. In the case of large conflicts, containment and termination of aggression by third parties is important. Successful intervention relies on consensus among combatants about the intervener's capacity to use force. We refer to this consensus as power. We measure it and study how it arises, using as our model system a pigtailed macaque (Macaca nemestrina) society. In macaques, the degree to which one individual perceives another as capable of using force is communicated using a special dominance signal. Group consensus about an individual's capacity to use force arises from the network of signaling interactions. We derive a formalism to quantify consensus in the network. We find that the power distribution is fat tailed and power is a strong predictor of social variables including request for support, intervention cost, and intensity. We develop models to show how dominance-signaling strategies promote robust power distributions despite individual signaling errors. We suggest that when considering correlated interactions among many individuals it can be more useful to emphasize coarse-grained information stored at the group level--behavioral macrostates--over detailed information at the individual level.