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Nguyen, N., Van Horn, R., Alberts, S., & Altmann, J. (2009). “Friendships” between new mothers and adult males: adaptive benefits and determinants in wild baboons (Papio cynocephalus). Behav. Ecol. Sociobiol., 63(9), 1331–1344.
Abstract: Close associations between adult males and lactating females and their dependent infants are not commonly described in non-monogamous mammals. However, such associations [sometimes called friendships (Smuts 1985)] are regularly observed in several primate species in which females mate with multiple males during the fertile period. The absence of mating exclusivity among friends suggests that males should invest little in infant care, raising questions about the adaptive significance of friendship bonds. Using data from genetic paternity analyses, patterns of behavior, and long-term demographic and reproductive records, we evaluated the extent to which friendships in four multi-male, multi-female yellow baboon (Papio cynocephalus) groups in Amboseli, Kenya represent joint parental care of offspring or male mating effort. We found evidence that mothers and infants benefited directly from friendships; friendships provided mother–infant dyads protection from harassment from other adult and immature females. In addition, nearly half of all male friends were the genetic fathers of offspring and had been observed mating with mothers during the days of most likely conception for those offspring. In contrast, nearly all friends who were not fathers were also not observed to consort with the mother during the days of most likely conception, suggesting that friendships between mothers and non-fathers did not result from paternity confusion. Finally, we found no evidence that prior friendship increased a male’s chances of mating with a female in future reproductive cycles. Our results suggest that, for many male–female pairs at Amboseli, friendships represented a form of biparental care of offspring. Males in the remaining friendship dyads may be trading protection of infants in exchange for some resources or services not yet identified. Our study is the first to find evidence that female primates gain social benefits from their early associations with adult males.
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Bhadra, A., Jordán, F., Sumana, A., Deshpande, S. A., & Gadagkar, R. (2009). A comparative social network analysis of wasp colonies and classrooms: Linking network structure to functioning. Ecol Complex, 6(1), 48–55.
Abstract: A major question in current network science is how to understand the relationship between structure and functioning of real networks. Here we present a comparative network analysis of 48 wasp and 36 human social networks. We have compared the centralisation and small world character of these interaction networks and have studied how these properties change over time. We compared the interaction networks of (1) two congeneric wasp species (Ropalidia marginata and Ropalidia cyathiformis), (2) the queen-right (with the queen) and queen-less (without the queen) networks of wasps, (3) the four network types obtained by combining (1) and (2) above, and (4) wasp networks with the social networks of children in 36 classrooms. We have found perfect (100%) centralisation in a queen-less wasp colony and nearly perfect centralisation in several other queen-less wasp colonies. Note that the perfectly centralised interaction network is quite unique in the literature of real-world networks. Differences between the interaction networks of the two wasp species are smaller than differences between the networks describing their different colony conditions. Also, the differences between different colony conditions are larger than the differences between wasp and children networks. For example, the structure of queen-right R. marginata colonies is more similar to children social networks than to that of their queen-less colonies. We conclude that network architecture depends more on the functioning of the particular community than on taxonomic differences (either between two wasp species or between wasps and humans).
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Franks, D., James, R., Noble, J., & Ruxton, G. (2009). A foundation for developing a methodology for social network sampling. Behav. Ecol. Sociobiol., 63(7), 1079-1088.
Abstract: Researchers are increasingly turning to network theory to understand the social nature of animal populations. We present a computational framework that is the first step in a series of works that will allow us to develop a quantitative methodology of social network sampling to aid ecologists in their social network data collection. To develop our methodology, we need to be able to generate networks from which to sample. Ideally, we need to perform a systematic study of sampling protocols on different known network structures, as network structure might affect the robustness of any particular sampling methodology. Thus, we present a computational tool for generating network structures that have user-defined distributions for network properties and for key measures of interest to ecologists. The user defines the values of these measures and the tool will generate appropriate network randomizations with those properties. This tool will be used as a framework for developing a sampling methodology, although we do not present a full methodology here. We describe the method used by the tool, demonstrate its effectiveness, and discuss how the tool can now be utilized. We provide a proof-of-concept example (using the assortativity measure) of how such networks can be used, along with a simulated egocentric sampling regime, to test the level of equivalence of the sampled network to the actual network.
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Fureix, C., Pagès, M., Bon, R., Lassalle, J. - M., Kuntz, P., & Gonzalez, G. (2009). A preliminary study of the effects of handling type on horses' emotional reactivity and the human-horse relationship. Behav. Process., 82(2), 202–210.
Abstract: Handling is a crucial component of the human-horse relationship. Here, we report data from an experiment conducted to assess and compare the effect of two training methods. Two groups of six Welsh mares were trained during four sessions of 50 min, one handled with traditional exercises (halter leading, grooming/brushing, lifting feet, lunging and pseudo-saddling (using only girth and saddle pad) and the second group with natural horsemanship exercises (desensitization, yielding to body pressure, lunging and free-lunging). Emotional reactivity (ER) and the human-horse relationship (HHR) were assessed both prior to and following handling. A social isolation test, a neophobia test and a bridge test were used to assess ER. HHR was assessed through test of spontaneous approach to, and forced approach by, an unknown human. Horses' ER decreased after both types of handling as indicated by decreases in the occurrence of whinnying during stressful situations. Head movement (jerk/shake) was the most sensitive variable to handling type. In the spontaneous approach tests, horses in the traditional handling group showed higher latencies to approach a motionless person after handling than did the natural horsemanship group. Our study suggests that natural horsemanship exercises could be more efficient than traditional exercises for improving horses' HHR.
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Majolo, B., Ventura, R., & Koyama, N. F. (2009). A Statistical Modelling Approach to the Occurrence and Timing of Reconciliation in Wild Japanese Macaques. Ethology, 115(2), 152–166.
Abstract: In various social species, animals have been observed to share friendly relationships with some group members and to resolve conflicts through reconciliation, the exchange of affiliative behaviour soon after a conflict that functions to restore the relationship between the former opponents. The valuable relationship hypothesis predicts that reconciliation should be observed more often after conflicts between friends. Friendly relationships can be described by three dimensions (i.e. value, security and compatibility); however, research into the relative importance of these dimensions for the occurrence of reconciliation is sparse. Moreover, reconciliation may depend on factors other than the social relationship between opponents including, for example, their social status or the context of the conflict. Our study aimed at analysing which factors are important determinants of reconciliation and at testing the valuable relationship hypothesis, by analysing the relative effects of relationship value, security and compatibility on the occurrence and timing of reconciliation. We collected data on two troops of wild Japanese macaques living on Yakushima Island, Japan, and selected the best predicting variables of reconciliation using linear mixed models. Our results show that reconciliation occurs more frequently, and earlier, after conflicts between opponents who exchange a higher percentage of grooming. Two additional variables related to relationship security and value were selected in the best models: frequency of aggression and of approaches resulting in tolerated co-feeding. Among the variables not related to relationship quality, distance between opponents at the end of the conflict, kinship, sex of the opponents and context of conflict (i.e. during feeding or social time) were included in our models. Our findings support the valuable relationship hypothesis and, in particular, highlight that the fitness-related benefits of social relationships (i.e. the relationship value) are important determinants of the evolution of friendly relationships and reconciliation.
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Jennings, D. J., Carlin, C. M., & Gammell, M. P. (2009). A winner effect supports third-party intervention behaviour during fallow deer, Dama dama, fights. Anim. Behav., 77(2), 343–348.
Abstract: Male ungulates engage in intense competition for access to females during the breeding season. Although fights are generally dyadic level encounters, they are on occasion disrupted by the intervention of third-party males. We investigated these third-party interventions using predictions derived from Dugatkin's model (Dugatkin 1998, Proceedings of the Royal Society of London, Series B, 265, 433-437) of intervention behaviour. The model argues that when an individual successfully defeats an opponent there is an increase in the probability of winning a subsequent contest: a winner effect. Third-party intervention behaviour is predicted to occur as it serves to prevent either member of a competing dyad from successfully defeating his opponent, achieving a winner effect and subsequently becoming a threat to the intervener. Consistent with model predictions, our results show that intervening males held significantly higher rank than males that did not intervene and were also more likely to be dominant to both of the competing males. Intervening males did not selectively target competitors based on rank, nor did they target males based on overall dyadic rates of aggression between the intervener and competing males. Furthermore, interveners were more likely to have won their interaction immediately prior to intervention and were also likely to win their interaction subsequent to intervention when compared with contest success of the two competing males. Our results are consistent with predictions that support a winner effect for intervention behaviour in fallow deer fights.
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Zeitler-Feicht, M. H., Streit, S., & Dempfle, L. (2009). Abrufautomaten für Pferde im Offenlaufstall im Vergleich – Besuchshäufigkeit, Aufenthaltsdauer und Anzahl an Auseinandersetzungen [A comparison of automatic feeding systems for horses in run-out-sheds – frequency of visit, duration of stay and number of conflicts]. In KTBL-Schrift (Vol. 479).
Abstract: In 32 Offenlaufställen mit computergesteuerten Abrufstationen wurden die Aufenthaltsdauer
und Besuchshäufigkeit sowie das Droh- und Meideverhalten von 439 Pferden im
Füttererungsbereich erfasst. Je Betrieb erfolgten visuelle kontinuierliche Direktbeobachtungen
nach dem Tortenstückverfahren (6 x 4 Stunden) für je einen 24-Stunden-Tag.
Ziel war die Überprüfung der verschiedenen Bauausführungen der Abrufstationen unter
dem Aspekt der Tiergerechtheit. Eine Einwegstation reduzierte signifikant die Anzahl an Auseinandersetzungen
im Fütterungsbereich. Demgegenüber führten die für das fressende Pferd
tiergerechten Varianten (Fressstand mit Eingangssperre und ohne Austreibehilfe) zu einer
Erhöhung der Besuchshäufigkeit und Aufenthaltsdauer und somit auch zu einer erhöhten
Anzahl an Drohgesten. Doch insgesamt betrachtet, kann die Anzahl an sozionegativen
Interaktionen im Fütterungsbereich der Abrufstationen als relativ gering eingestuft werden.
Da sich außerdem der Betrieb (Management, Fläche, Konzeption) als maßgeblicher Einflussfaktor
auf die überprüften Parameter erwies, dürften die Unterschiede in der Bauausführung
der derzeitigen Abrufstationen für Pferde eher von untergeordneter Bedeutung sein.
[Duration of stay, frequency of visit, threatening gestures and behaviour of avoidance of
439 horses was observed at the feeding area of 32 run-out-sheds. The observation was based
on the method of visual continuously direct watching after the pie chart system (6 x 4 hours)
over a period of 24 hours. The observation should show which construction of the different
automatic feeding systems corresponded best under the aspect of animal welfare.
It was obvious that the one-way-station reduced significantly the number of conflicts
in the feeding area, whereas those systems which are appropriate for the eating horses
(feeding station with access barrier and without stimulation device by electric shock) led
to a higher frequency of visits and duration of stay as well as to more threatening gestures.
Considering altogether, the number of negative interactions in the feeding area of the feeding
systems can be classified as comparatively unimportant. As it showed that the stable
(management, stable area, conception) was of important influence on the surveyed parameters,
the differences between the constructions of feeding stations for horses of present
systems are probably of less meaning.]
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Reddon, A. R., & Hurd, P. L. (2009). Acting unilaterally: Why do animals with strongly lateralized brains behave differently than those with weakly lateralized brains? Bioscience Hypotheses, 2(6), 383–387.
Abstract: Cerebral lateralization was once thought to be unique to humans, but is now known to be widespread among the vertebrates. Lateralization appears to confer cognitive advantages upon those that possess it. Despite the taxonomic ubiquity and described advantages of lateralization, substantial individual variation exists in all species. Individual variation in cerebral lateralization may be tied to individual variation in behaviour and the selective forces that act to maintain variation in behaviour may also act to maintain variation in lateralization. The mechanisms linking individual variation in the strength of cerebral lateralization to individual variation in behaviour remain obscure. We propose here a general hypothesis which may help to explain this link. We suggest that individuals with strong and weak lateralizations behave differently because of differences in the ability of one hemisphere to inhibit the functions of the other in each type of brain organization. We also suggest a specific mechanism involving the asymmetric epithalamic nucleus, the habenula. We conclude by discussing some predictions and potential tests of our hypothesis.
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Schultheiss, O. C., Riebel, K., & Jones, N. M. (2009). Activity inhibition: A predictor of lateralized brain function during stress? Neuropsychology, 23(3), 392–404.
Abstract: The authors tested the hypothesis that activity inhibition (AI), a measure of the frequency of the word “not” in written material, marks a propensity to engage functions of the right hemisphere (RH) and disengage functions of the left hemisphere (LH), particularly during stress. Study 1 and Study 2 showed that high AI predicts faster detection of stimuli presented to the RH, relative to the LH. Study 2 provided evidence that the AI-laterality effect is specific to perceptual, but not motor, laterality and that it is particularly strong in individuals with low mood, but absent in individuals in a positive mood state. Study 3 showed that negative affective stimuli prime the AI-laterality effect more strongly than positive affective stimuli. Findings from Study 4 suggest that situationally induced frustration (losing a contest), in conjunction with high AI, leads to increased attentional laterality. The present findings substantially bolster the construct validity of AI and contribute to a better understanding of earlier findings linking AI to physiological stress responses, immune system functioning, alcohol abuse, and nonverbal behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)
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Reid, P. J. (2009). Adapting to the human world: Dogs' responsiveness to our social cues. Behav. Process., 80(3), 325–333.
Abstract: Dogs are more skilful than a host of other species at tasks which require they respond to human communicative gestures in order to locate hidden food. Four basic interpretations for this proficiency surface from distilling the research findings. One possibility is that dogs simply have more opportunity than other species to learn to be responsive to human social cues. A different analysis suggests that the domestication process provided an opening for dogs to apply general cognitive problem-solving skills to a novel social niche. Some researchers go beyond this account and propose that dogs' co-evolution with humans equipped them with a theory of mind for social exchanges. Finally, a more prudent approach suggests that sensitivity to the behaviours of both humans and conspecifics would be particularly advantageous for a social scavenger like the dog. A predisposition to attend to human actions allows for rapid early learning of the association between gestures and the availability of food.
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