Altruism, benefiting another at a cost to the donor, may be achieved through prosocial behavior. Studies of nonhuman animals typically investigate prosocial behavior with paradigms in which the donor ...can choose to give a recipient a food item, and the choice does not affect the donor's reward (which is either present or absent). In such tasks, long-tailed macaques (Macaca fascicularis) show prosocial behavior, especially toward kin. Here, we tested captive long-tailed macaques with related recipients in an alternative task, in which the donor had to give up a preferred reward to benefit the recipient; that is, they had to choose a lower valued reward for themselves to provide food to their kin. Overall, the macaques did not provide their kin with food. The task forced the donor to balance its prosocial behavior with its selfish choice for a higher value reward, a balance that turned out to favor selfish motives. Consequently, our study shows that a prosocial tendency is not sufficient to elicit costly prosocial behavior in long-tailed macaques. Subsequently, we feel that tasks in which the donor must choose a lower value reward to benefit another individual may allow the titration of the strength of prosocial behavior, and thus provides interesting possibilities for future comparative studies.
Allogrooming in primates serves not only a hygienic function, but also plays a crucial role in maintaining strong affiliative bonds between group members, which in turn, underpin the emergence of ...cooperative behavior. In contrast, although allopreening occurs in many avian species, we know little about its social functions. Our study addresses this issue by investigating allopreening in a broad comparative data set including six corvid and nine parrot species. We assessed whether rates of allopreening initiations, proportion of time spent allopreening, and the number of grooming partners in captive group‐housed birds were comparable to patterns observed in captive chimpanzees and bonobos. While parrots and corvids were found to have similar rates of social grooming to bonobos and chimpanzees, Pan species dedicated significantly more time to social grooming. Animals in larger groups had more grooming partners, but when controlling for the number of potential partners, birds tended to have fewer grooming interaction partners than Pan species. We then investigated whether allopreening in parrots and corvids was predicted by behavioral markers of affiliative social bonds (close physical proximity, active feeding, and low levels of agonistic behavior). Results revealed that providing allopreening to a partner was significantly predicted by often being in close proximity, but not engagement in active feeding or agonistic behavior. We examined the region allopreened in a subset of species and found that preening a partner's head was predicted by both close physical proximity and active feeding, while body allopreening was only predicted by close physical proximity. Head preening may confer more hygienic benefits to recipients, and thus, may be more selectively provided to valued partners. Results support the hypothesis that allopreening in corvids and parrots helps maintain social bonds with an individual's most important social partners, showing some similarities to allogrooming in primates.
Parrots and corvids were more likely to allopreen partners that they chose to maintain close physical proximity with. When examining the region allopreened, we found that preening a partner's head was predicted by frequent close proximity and active feeding, indicating this might be a more valuable service reserved for highly valued social partners. Compared to Pan species, parrots and corvids initiated grooming bouts at similar rates, but invested less time in grooming and engaged with fewer partners. The figure illustrates the probability of dyadic allopreening being observed within a given dyad, as a function of their proximity score. Data illustrated derives from the model testing if occurrence of allopreening in a dyad could be predicted by proximity and active feeding (N = 118 individuals from nine species). Each dot shows the average probability per bin of the proximity score, whereby the area of the dots depicts the number of dyads per dot (N = 1 to 1,005). The dashed and dotted lines depict the fitted model and its confidence interval (with all other predictors in the model being at their average and assuming an observation effort of 4 hr, which roughly equals the average observation effort). Allopreening was more likely to occur in dyads that spent a higher proportion of their time in close physical proximity.
Animals experience stressful situations, from predation to social conflicts, but mostly deal with them successfully. This adaptive mechanism, coping, reduces the adverse effects of stressors, and its ...failure may result in reduced fitness. Substantial inter-individual variation in coping is observed, yet little is known about how behavioral, physiological and genetic drivers regulate coping holistically and contribute to such variations. We assessed behavioral coping styles (n=30), emotional arousal (n=12), and personalities (n=32) of long-tailed macaques (Macaca fascicularis) and also investigated the association of coping with a valine/methionine polymorphism encoded by a critical human stress regulatory gene, catechol-O-methyltransferase (COMT) (n=26). Personality and the human equivalent COMT Val/Met polymorphism were associated with “nonaggression-based” and “aggression-based” coping styles. Compared to nonaggression-based, aggression-based copers maintained higher average facial temperatures, indicating potentially lower emotional arousal, as measured using infrared thermography. These findings demonstrate a complex interplay of various proximate mechanisms governing coping in a non-human primate.
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•Long-tailed macaques exhibit “aggression-” and “nonaggression-based” coping styles•Behavioral coping styles show consistency with emotional arousal•A human equivalent COMT Val/Met polymorphism is present in long-tailed macaques•Personality and COMT Val/Met polymorphism are linked to coping in long-tailed macaques
Evolutionary biology; Genetics; Zoology
One hallmark in the evolution of cooperation is the ability to evaluate one's own payoff for a task against that of another person. To trace its evolutionary history, there has recently been a surge ...in comparative studies across different species. In non‐human animals, evidence of inequity aversion has so far been identified in several primate species, dogs, and rats. Research in birds revealed mixed findings so far: among corvids, crows and ravens did react sensitively to unequal payoffs and work‐effort, while New Caledonian crows did not. Among psittacids, kea were studied so far: Yet, despite the fact that they live in large, hierarchically organized social groups that show complex interactions, they did not show a significant reaction to inequitable payoffs. Here we tested for the first time a Cacatua, the Goffin's cockatoo, using a standardized token exchange paradigm in which first the partner and then the subject could exchange a token for a food reward. Our results show that subjects did not react to unequal reward distributions. However, in comparison to the Equity Condition, the likelihood to exchange was lower in the condition in which the partner received the same reward as a gift (without having to work for it) whereas the subject had to perform a task involving substantial work‐effort, suggesting that the Goffin's cockatoos do react aversively to work‐effort inequity. In a follow‐up experiment, subjects never received a reward but observed a conspecific receive a high‐quality reward depending on condition. We found again no evidence for an aversion for the unequal reward distribution, but only that, independent of condition, subjects quickly lost their motivation to participate due to not receiving a reward. In summary, Goffins showed some sensitivity to increased unequal work‐effort, but did not react to unequal reward distribution.
The overt and reflexive matching of behaviors among conspecifics has been observed in a growing number of social vertebrates, including avian species. In general, behavioral contagion-such as the ...spread of yawning-may serve important functions in group synchronization and vigilance behavior. Here, we performed an exploratory study to investigate yawn contagion among 10 captive juvenile ravens (
), across two groups. Using observational methods, we also examined the contagiousness of three other distinct behaviors: stretching, scratching, and shaking. A total of 44 20 min observations were made across both groups, including 28 in the morning and 16 in the afternoon. The time and occurrence of all the behaviors from each bird were coded, and the temporal pattern of each behavior across both groups was then analyzed to assess the degree of social contagion. Overall, we found no evidence for contagious yawning, stretching, scratching, or shaking. However, yawns were relatively infrequent per observation (0.052 ± 0.076 yawns/bird) and thus experimental methods should be used to support this finding.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
The neuropeptide oxytocin influences mammalian social bonding by facilitating the building and maintenance of parental, sexual, and same‐sex social relationships. However, we do not know whether the ...function of the avian homologue mesotocin is evolutionarily conserved across birds. While it does influence avian prosocial behavior, mesotocin's role in avian social bonding remains unclear. Here, we investigated whether mesotocin regulates the formation and maintenance of same‐sex social bonding in pinyon jays (Gymnorhinus cyanocephalus), a member of the crow family. We formed squads of four individually housed birds. In the first, “pair‐formation” phase of the experiment, we repeatedly placed pairs of birds from within the squad together in a cage for short periods of time. Prior to entering the cage, we intranasally administered one of three hormone solutions to both members of the pair: mesotocin, oxytocin antagonist, or saline. Pairs received repeated sessions with administration of the same hormone. In the second, “pair‐maintenance” phase of the experiment, all four members of the squad were placed together in a large cage, and no hormones were administered. For both phases, we measured the physical proximity between pairs as our proxy for social bonding. We found that, compared with saline, administering mesotocin or oxytocin antagonist did not result in different proximities in either the pair‐formation or pair‐maintenance phase of the experiment. Therefore, at the dosages and time frames used here, exogenously introduced mesotocin did not influence same‐sex social bond formation or maintenance. Like oxytocin in mammals, mesotocin regulates avian prosocial behavior; however, unlike oxytocin, we do not have evidence that mesotocin regulates social bonds in birds.
Scientific Reports 5: Article number: 16439; Published online: 10 November 2015; updated: 29 April 2016 The Acknowledgements section in this Article is incomplete. “We thank the primate sanctuary in ...Gaenserndorf, Austria, and Burgers’ Zoo, Arnhem, and Dierenpark Amersfoort, The Netherlands, and especially all the keepers for their great enthusiasm and cooperation during the study.
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