The Evolution of Reptilian Social Behavior

Reptiles display a diversity of behavior that is reflectiveof their evolutionary heritage from fish and amphibians andtheir ancestral contribution to the diversity found in birdsand mammals. Much of the behavior observed in reptiles seemsspecific to the ecological setting within which they live. Asa result, a diversity of behavior is found in each of the groupsof modern reptiles. Recent studies on the social behavior oflizards have proved them capable of a variety of behavioralpostures, sequences, and sociality that exceeds that found insome mammals and birds. While many species of lizards are territorial,others are hierarchial and some have harems. For all those territorialspecies studied, crowding results in increased social interaction,increased aggression, and a switch to hierarchial behavior. While smell and sound may be important stimuli for social behaviorin some reptiles, posture, actions, and especially color appearto be most important in diurnal lizards. Temperature and energystudies suggest that the large extinct dinosaurs probably foughtconsiderably less than commonly portrayed in movies and stories,but were also probably much more brightly colored than commonlyshown in reconstructions.     

Wolves Are Better Imitators of Conspecifics than Dogs

Domestication is thought to have influenced the cognitive abilities of dogs underlying their communication with humans, but little is known about its effect on their interactions with conspecifics. Since domestication hypotheses offer limited predictions in regard to wolf-wolf compared to dog-dog interactions, we extend the cooperative breeding hypothesis suggesting that the dependency of wolves on close cooperation with conspecifics, including breeding but also territory defense and hunting, has created selection pressures on motivational and cognitive processes enhancing their propensity to pay close attention to conspecifics’ actions. During domestication, dogs’ dependency on conspecifics has been relaxed, leading to reduced motivational and cognitive abilities to interact with conspecifics. Here we show that 6-month-old wolves outperform same aged dogs in a two-action-imitation task following a conspecific demonstration. While the wolves readily opened the apparatus after a demonstration, the dogs failed to solve the problem. This difference could not be explained by differential motivation, better physical insight of wolves, differential developmental pathways of wolves and dogs or a higher dependency of dogs from humans. Our results are best explained by the hypothesis that higher cooperativeness may come together with a higher propensity to pay close attention to detailed actions of others and offer an alternative perspective to domestication by emphasizing the cooperativeness of wolves as a potential source of dog-human cooperation.     

The Effect of Domestication on Inhibitory Control: Wolves and Dogs Compared

Inhibitory control i.e. blocking an impulsive or prepotent response in favour of a more appropriate alternative, has been suggested to play an important role in cooperative behaviour. Interestingly, while dogs and wolves show a similar social organization, they differ in their intraspecific cooperation tendencies in that wolves rely more heavily on group coordination in regard to hunting and pup-rearing compared to dogs. Hence, based on the ‘canine cooperation’ hypothesis wolves should show better inhibitory control than dogs. On the other hand, through the domestication process, dogs may have been selected for cooperative tendencies towards humans and/or a less reactive temperament, which may in turn have affected their inhibitory control abilities. Hence, based on the latter hypothesis, we would expect dogs to show a higher performance in tasks requiring inhibitory control. To test the predictive value of these alternative hypotheses, in the current study two tasks; the ‘cylinder task’ and the ‘detour task’, which are designed to assess inhibitory control, were used to evaluate the performance of identically raised pack dogs and wolves. Results from the cylinder task showed a significantly poorer performance in wolves than identically-raised pack dogs (and showed that pack-dogs performed similarly to pet dogs with different training experiences), however contrary results emerged in the detour task, with wolves showing a shorter latency to success and less perseverative behaviour at the fence. Results are discussed in relation to previous studies using these paradigms and in terms of the validity of these two methods in assessing inhibitory control.     

Social Modulation of Contagious Yawning in Wolves

On the basis of observational and experimental evidence, several authors have proposed that contagious yawn is linked to our capacity for empathy, thus presenting a powerful tool to explore the root of empathy in animal evolution. The evidence for the occurrence of contagious yawning and its link to empathy, however, is meagre outside primates and only recently domestic dogs have demonstrated this ability when exposed to human yawns. Since dogs are unusually skilful at reading human communicative behaviors, it is unclear whether this phenomenon is deeply rooted in the evolutionary history of mammals or evolved de novo in dogs as a result of domestication. Here we show that wolves are capable of yawn contagion, suggesting that such ability is a common ancestral trait shared by other mammalian taxa. Furthermore, the strength of the social bond between the model and the subject positively affected the frequency of contagious yawning, suggesting that in wolves the susceptibility of yawn contagion correlates with the level of emotional proximity. Moreover, female wolves showed a shorter reaction time than males when observing yawns of close associates, suggesting that females are more responsive to their social stimuli. These results are consistent with the claim that the mechanism underlying contagious yawning relates to the capacity for empathy and suggests that basic building blocks of empathy might be present in a wide range of species.     

Social Relationships in a Group of Captive Wolves

The social organization of a group of wolves in a large outdoorenclosure was followed through several breeding seasons. Duringthe breeding season conflicts become more frequent and the socialhierarchy obvious. The more dominant animals restrict courtshipactivities by inferior wolves of their own sex. However, apparentlyas a correlate of their position, two alpha males have shownless mating activity than other males. Mate preferences exhibitedby animals of both sexes also limit the number of matings. Thepreferences appear related to the social hierarchy existingwhen an animal matures. Cultural transmission of social statusis suggested by some changes in ranking of wolves raised inthe woods at Brookfield. Temporary removal of the original alphamale and death of the original alpha female appear to have promotedchanges in social order and an increase in actual mating combinations.The probable consanguineous nature of wolf groups and facetsof the social behavior suggest that some form of group selectioncould be operative in the wild.     

From Wolves to Dogs,and Back: Genetic Composition of the Czechoslovakian Wolfdog

The Czechoslovakian Wolfdog is a unique dog breed that originated from hybridization between German Shepherds and wild Carpathian wolves in the 1950s as a military experiment. This breed was used for guarding the Czechoslovakian borders during the cold war and is currently kept by civilian breeders all round the world. The aim of our study was to characterize, for the first time, the genetic composition of this breed in relation to its known source populations. We sequenced the hypervariable part of the mtDNA control region and genotyped the Amelogenin gene, four sex-linked microsatellites and 39 autosomal microsatellites in 79 Czechoslovakian Wolfdogs, 20 German Shepherds and 28 Carpathian wolves. We performed a range of population genetic analyses based on both empirical and simulated data. Only two mtDNA and two Y-linked haplotypes were found in Czechoslovakian Wolfdogs. Both mtDNA haplotypes were of domestic origin, while only one of the Y-haplotypes was shared with German Shepherds and the other was unique to Czechoslovakian Wolfdogs. The observed inbreeding coefficient was low despite the small effective population size of the breed, possibly due to heterozygote advantages determined by introgression of wolf alleles. Moreover, Czechoslovakian Wolfdog genotypes were distinct from both parental populations, indicating the role of founder effect, drift and/or genetic hitchhiking. The results revealed the peculiar genetic composition of the Czechoslovakian Wolfdog, showing a limited introgression of wolf alleles within a higher proportion of the dog genome, consistent with the reiterated backcrossing used in the pedigree. Artificial selection aiming to keep wolf-like phenotypes but dog-like behavior resulted in a distinctive genetic composition of Czechoslovakian Wolfdogs, which provides a unique example to study the interactions between dog and wolf genomes.     

Evolution of Social Behavior in Spiders (Araneae; Eresidae and Theridiidae)

Whereas most spiders are asocial, species in eight familiesare known to live all their life in communities and are thus"permanent-social." Their special attributes are: tolerance,interattraction, and cooperation. These peculiarities must havebeen achieved step by step several times independently. Periodic-socialspiders have been studied as a link between asocial and permanent-socialspiders. In two families—the cribellate Eresidae and ecribellateTheridiidae—different steps of periodic sociality havebeen discovered, from brood-care to feeding by regurgitation.The comparative study of the phylogeny of social behavior inboth families uncovers remarkable convergences of patterns fromasocial to permanent-social via periodical-social species ofspiders.     

Exploring Social (Non-working) Behavior in Guide Dogs from the Perspective of Guide Dog Owners

The guide dog partnership begins at the point of matching, when careful assessment of a trained guide dog and an understanding of the functional needs and expectations of the prospective owner are considered alongside each other. Guide Dogs UK invest much time and resources to the process of matching a client with a dog in order to fulfil client expectations and create a lasting partnership. This study explores: (1) the meaning and importance of social (non-working) behavior to guide dog owners; (2) how firsthand experience and knowledge shape individual owner expectations for behavior; and (3) how, and in what ways, social behavior impacts the guide dog partnership. The focus group method was used to collect qualitative data from a total of 11 participants. The data were analyzed using a thematic analysis procedure which identified six overarching themes: “social behavior to me means,” internal and external factors influencing social behavior, training and matching, socially desirable and undesirable behaviors, maintaining and managing social behavior, and practical and emotional issues. Findings show that social behavior is as important as guiding skills and mobility for guide dog owners, and behavioral compatibility is held to be crucial in a successful partnership. Participants put an emphasis on consistency of behavior in social settings, while recognizing that a guide dog's non-working behavior is subject to multifarious internal and external influences. The findings of this study indicate an opportunity for Guide Dogs UK, and similar assistance dog organizations, to observe fully the importance of social behavior and, in response, place even greater emphasis on lifestyle and behavioral compatibility when training dogs and matching them with clients.     

The Evolution of Human Homosexual Behavior

Homosexuality presents a paradox for evolutionists who explore the adaptedness of human behavior. If adaptedness is measured by reproductive success and if homosexual behavior is nonreproductive, how has it come about? Three adaptationist hypotheses are reviewed here and compared with the anthropological literature. There is little evidence that lineages gain reproductive advantage through offspring care provided by homosexual members. Therefore, there is little support for the hypothesis that homosexuality evolved by kin selection. Parents at times control children's reproductive decisions and at times encourage children in homosexual behavior. There is therefore more support for the hypothesis of parental manipulation. Support is strongest, however, for the hypothesis that homosexual behavior comes from individual selection for reciprocal altruism. Same-sex alliances have reproductive advantages, and sexual behavior at times maintains these alliances. Nonhuman primates, including the apes, use homosexual behavior in same-sex alliances, and such alliances appear to have been key in the expanded distribution of human ancestors during the Pleistocene. Homosexual emotion and behavior are, in part, emergent qualities of the human propensity for same-sex affiliation. Adaptationist explanations do not fully explain sexual behavior in humans, however; social and historical factors also play strong roles.     

The Evolution of Human Homosexual Behavior

Homosexuality presents a paradox for evolutionists who explore the adaptedness of human behavior. If adaptedness is measured by reproductive success and if homosexual behavior is nonreproductive, how has it come about? Three adaptationist hypotheses are reviewed here and compared with the anthropological literature. There is little evidence that lineages gain reproductive advantage through offspring care provided by homosexual members. Therefore, there is little support for the hypothesis that homosexuality evolved by kin selection. Parents at times control children's reproductive decisions and at times encourage children in homosexual behavior. There is therefore more support for the hypothesis of parental manipulation. Support is strongest, however, for the hypothesis that homosexual behavior comes from individual selection for reciprocal altruism. Same-sex alliances have reproductive advantages, and sexual behavior at times maintains these alliances. Nonhuman primates, including the apes, use homosexual behavior in same-sex alliances, and such alliances appear to have been key in the expanded distribution of human ancestors during the Pleistocene. Homosexual emotion and behavior are, in part, emergent qualities of the human propensity for same-sex affiliation. Adaptationist explanations do not fully explain sexual behavior in humans, however; social and historical factors also play strong roles.     

The Evolution of Human Homosexual Behavior

Homosexuality presents a paradox for evolutionists who explore the adaptedness of human behavior. If adaptedness is measured by reproductive success and if homosexual behavior is nonreproductive, how has it come about? Three adaptationist hypotheses are reviewed here and compared with the anthropological literature. There is little evidence that lineages gain reproductive advantage through offspring care provided by homosexual members. Therefore, there is little support for the hypothesis that homosexuality evolved by kin selection. Parents at times control children's reproductive decisions and at times encourage children in homosexual behavior. There is therefore more support for the hypothesis of parental manipulation. Support is strongest, however, for the hypothesis that homosexual behavior comes from individual selection for reciprocal altruism. Same-sex alliances have reproductive advantages, and sexual behavior at times maintains these alliances. Nonhuman primates, including the apes, use homosexual behavior in same-sex alliances, and such alliances appear to have been key in the expanded distribution of human ancestors during the Pleistocene. Homosexual emotion and behavior are, in part, emergent qualities of the human propensity for same-sex affiliation. Adaptationist explanations do not fully explain sexual behavior in humans, however; social and historical factors also play strong roles.     

Bucking the Trend in Wolf-Dog Hybridization: First Evidence from Europe of Hybridization between Female Dogs and Male Wolves

Studies on hybridization have proved critical for understanding key evolutionary processes such as speciation and adaptation. However, from the perspective of conservation, hybridization poses a concern, as it can threaten the integrity and fitness of many wild species, including canids. As a result of habitat fragmentation and extensive hunting pressure, gray wolf (Canis lupus) populations have declined dramatically in Europe and elsewhere during recent centuries. Small and fragmented populations have persisted, but often only in the presence of large numbers of dogs, which increase the potential for hybridization and introgression to deleteriously affect wolf populations. Here, we demonstrate hybridization between wolf and dog populations in Estonia and Latvia, and the role of both genders in the hybridization process, using combined analysis of maternal, paternal and biparental genetic markers. Eight animals exhibiting unusual external characteristics for wolves - six from Estonia and two from Latvia - proved to be wolf-dog hybrids. However, one of the hybridization events was extraordinary. Previous field observations and genetic studies have indicated that mating between wolves and dogs is sexually asymmetrical, occurring predominantly between female wolves and male dogs. While this was also the case among the Estonian hybrids, our data revealed the existence of dog mitochondrial genomes in the Latvian hybrids and, together with Y chromosome and autosomal microsatellite data, thus provided the first evidence from Europe of mating between male wolves and female dogs. We discuss patterns of sexual asymmetry in wolf-dog hybridization.     

The Evolution of Allomothering Behavior Among Colobine Monkeys: Function and Opportunism in Evolution

The great majority of Old World monkey females are interested in infants, particularly very young ones. Characteristically, females will approach infants cradled by their mothers and subsequently attempt to touch or hold them. For Cercopithecine monkeys, the subfamily that includes the baboons and macaques, caretaking attempts by females other than the mother are ordinarily unsuccessful, at least during the first two or three weeks of life. Mothers are highly possessive of their offspring and will not surrender them to substitute infant-caretakers. In striking contrast, among the other major subfamily of Old World monkeys, the Colobines, mothers readily allow extensive and sometimes prolonged infant carrying and handling by other females (allomothering), even on the first day of life. This paper reviews the traditional functional explanations for these different maternal systems. Stressing opportunism in evolution, the paper suggests that the social and/or genetic benefits alone are not adequate to account for the origins of allomothering behavior among Colobines. Instead, emphasis is given to the kind of ancestral social structure and its environmental context that might allow such a behavioral system to begin. It is hypothesized that, relative to the Cercopithecines, who do not exhibit infant-sharing, the dental morphology and digestive system of the Colobines produced food-acquiring and food-processing advantages that, in effect, reduced intragroup feeding competition and, concomitantly, reduced the importance of status differences between females. Such a social structure could permit the emergence of allomothering behavior since, for all the participants in this activity pattern, there are varying benefits that contribute to individual fitness. [Colobine, allomothering, functions, opportunism, dietary adaptations, social structure]     

In-Kennel Behavior Predicts Length of Stay in Shelter Dogs

Previous empirical evaluations of training programs aimed at improving dog adoption rates assume that dogs exhibiting certain behaviors are more adoptable. However, no systematic data are available to indicate that the spontaneous behavior of shelter dogs has an effect on adopter preference. The aim of the present study was to determine whether any behaviors that dogs exhibit spontaneously in the presence of potential adopters were associated with the dogs'' length of stay in the shelter. A sample of 289 dogs was videotaped for 1 min daily throughout their stay at a county shelter. To account for differences in adopter behavior, experimenters varied from solitary passive observers to pairs of interactive observers. Dogs behaved more attentively to active observers. To account for adopter preference for morphology, dogs were divided into “morphologically preferred” and “non-preferred” groups. Morphologically preferred dogs were small, long coated, ratters, herders, and lap dogs. No theoretically significant differences in behavior were observed between the two different dog morphologies. When accounting for morphological preference, three behaviors were found to have a significant effect on length of stay in all dogs: leaning or rubbing on the enclosure wall (increased median length of stay by 30 days), facing away from the front of the enclosure (increased by 15 days), and standing (increased by 7 days). When combinations of behaviors were assessed, back and forth motion was found to predict a longer stay (increased by 24 days). No consistent behavioral changes were observed due to time spent at the shelter. These findings will allow shelters to focus behavioral modification efforts only on behaviors likely to influence adopters'' choices.     

前额叶皮层在社交行为中的作用

社交行为对于个体身心健康和社会发展都极其重要。社交行为障碍已成为多种精神类疾病的典型临床表征,对个体的发展有严重不良影响。前额叶皮层作为调节社交行为的关键脑区之一,参与了社交、情绪、决策等高级功能,其内部神经元、神经胶质细胞的活动变化及相互作用对调节社交行为有着重要影响,而且前额叶皮层与其他脑区之间的协作也会影响不同的社会行为。本文回顾了前额叶皮层中神经元、神经胶质细胞以及脑区投射与社交行为关系的最新研究,系统综述了前额叶皮层在社交行为调节中的作用,以期为社交障碍的神经机制和有效诊疗提供参考。     

The Effects of Breeder Loss on Wolves

Abstract Managers of recovering wolf (Canis lupus) populations require knowledge regarding the potential impacts caused by the loss of territorial, breeding wolves when devising plans that aim to balance population goals with human concerns. Although ecologists have studied wolves extensively, we lack an understanding of this phenomenon as published records are sparse. Therefore, we pooled data (n = 134 cases) on 148 territorial breeding wolves (75 M and 73 F) from our research and published accounts to assess the impacts of breeder loss on wolf pup survival, reproduction, and territorial social groups. In 58 of 71 cases (84%), ≥1 pup survived, and the number or sex of remaining breeders (including multiple breeders) did not influence pup survival. Pups survived more frequently in groups of ≥6 wolves (90%) compared with smaller groups (68%). Auxiliary nonbreeders benefited pup survival, with pups surviving in 92% of cases where auxiliaries were present and 64% where they were absent. Logistic regression analysis indicated that the number of adult-sized wolves remaining after breeder loss, along with pup age, had the greatest influence on pup survival. Territorial wolves reproduced the following season in 47% of cases, and a greater proportion reproduced where one breeder had to be replaced (56%) versus cases where both breeders had to be replaced (9%). Group size was greater for wolves that reproduced the following season compared with those that did not reproduce. Large recolonizing (>75 wolves) and saturated wolf populations had similar times to breeder replacement and next reproduction, which was about half that for small recolonizing (≤75 wolves) populations. We found inverse relationships between recolonizing population size and time to breeder replacement (r= —0.37) and time to next reproduction (r= —0.36). Time to breeder replacement correlated strongly with time to next reproduction (r=0.97). Wolf social groups dissolved and abandoned their territories subsequent to breeder loss in 38% of cases. Where groups dissolved, wolves reestablished territories in 53% of cases, and neighboring wolves usurped territories in an additional 21% of cases. Fewer groups dissolved where breeders remained (26%) versus cases where breeders were absent (85%). Group size after breeder loss was smaller where groups dissolved versus cases where groups did not dissolve. To minimize negative impacts, we recommend that managers of recolonizing wolf populations limit lethal control to solitary individuals or territorial pairs where possible, because selective removal of pack members can be difficult. When reproductive packs are to be managed, we recommend that managers only remove wolves from reproductive packs when pups are ≥6 months old and packs contain ≥6 members (including ≥3 ad-sized wolves). Ideally, such packs should be close to neighboring packs and occur within larger (≥75 wolves) recolonizing populations.     

A Comparison of the Sensory Development of Wolves (Canis lupus lupus) and Dogs (Canis lupus familiaris)

Little is known about the development of the sensory systems of wolves. The timing of sensory development in wolves is usually extrapolated from studies on dogs, since they are members of the same species. However, early developmental differences between these two subspecies have already been identified. For example, wolves tend to approach and investigate objects in their environment 2 wk before dogs. These changes in developmental timing may play an important role in the behavioral differences between adult wolves and dogs. The purpose of this study is to compare the development of the sensory systems in wolves and dogs. Responses of seven wolf pups and 43 dog pups to familiar and novel olfactory, auditory, and visual stimuli were tested weekly from 2–7 wk of age. Eleven wolf pups were also observed for orientation towards auditory and visual stimuli during 2‐h sessions, 5 d a week, from 2–8 wk of age. These observations were supplemented by the daily records of caretakers. The results suggest that wolves and dogs both develop olfaction by 2 wk, audition by 4 wk, and vision by 6 wk on average, despite the 2‐wk shift in their ability to explore. This means that when wolves begin to explore at 2 wk, they are blind and deaf, and must rely primarily on their sense of smell. Thus, there is a significant alteration of how these subspecies experience their environment during the critical period of socialization. These findings lead to an alternative explanation for the difference in dogs' and wolves' abilities to form interspecies social attachments, such as those with humans.