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von Borstel, U. U. K., Duncan, I. J. H., Lundin, M. C., & Keeling, L. J. (2010). Fear reactions in trained and untrained horses from dressage and show-jumping breeding lines. Appl. Anim. Behav. Sci., 125(3–4), 124–131.
Abstract: Horses’ fear reactions are hazardous to both horses and human beings, but it is not clear whether fear is influenced more by training or by other factors such as genetics. The following study was designed to detect differences between young, untrained (U) and older, well-trained (T) horses of dressage (D), show-jumping (J), and mixed (M) genetic lines with regard to intensity of reaction and ease of habituation to a frightening stimulus. In five consecutive trials, 90 horses were exposed to a standardized fear-eliciting stimulus where intensity and duration of the reactions were recorded. Repeated measures analysis showed that flight reactions by J were less intense (p < 0.05) than those by D or M regardless of training status or age. Habituation to the stimulus over time was not significantly (p > 0.1) different between the disciplines, as indicated by similar slopes for all measurements, but reaction vigour declined faster for T than for U. These findings indicate that there may be a genetic basis for less strong, though not shorter-lasting, fear reactions in J compared to D or M lines of horses. Research including the estimation of genetic correlations between traits related to fearfulness and to performance would be required to verify this assumption.
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Bang, A., Deshpande, S., Sumana, A., & Gadagkar, R. (2010). Choosing an appropriate index to construct dominance hierarchies in animal societies: a comparison of three indices. Animal Behaviour, 79(3), 631–636.
Abstract: A plethora of indices have been proposed and used to construct dominance hierarchies in a variety of vertebrate and invertebrate societies, although the rationale for choosing a particular index for a particular species is seldom explained. In this study, we analysed and compared three such indices, viz Clutton-Brock et al.'s index (CBI), originally developed for red deer, Cervus elaphus, David's score (DS) originally proposed by the statistician H. A. David and the frequency-based index of dominance (FDI) developed and routinely used by our group for the primitively eusocial wasps Ropalidia marginata and Ropalidia cyathiformis. Dominance ranks attributed by all three indices were strongly and positively correlated for both natural data sets from the wasp colonies and for artificial data sets generated for the purpose. However, the indices differed in their ability to yield unique (untied) ranks in the natural data sets. This appears to be caused by the presence of noninteracting individuals and reversals in the direction of dominance in some of the pairs in the natural data sets. This was confirmed by creating additional artificial data sets with noninteracting individuals and with reversals. Based on the criterion of yielding the largest proportion of unique ranks, we found that FDI is best suited for societies such as the wasps belonging to Ropalidia, DS is best suited for societies with reversals and CBI remains a suitable index for societies such as red deer in which multiple interactions are uncommon.
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Gruber, T., Clay, Z., & Zuberbühler, K. (2010). A comparison of bonobo and chimpanzee tool use: evidence for a female bias in the Pan lineage. Anim. Behav., 80(6), 1023–1033.
Abstract: Chimpanzees, Pan troglodytes, are the most sophisticated tool-users among all nonhuman primates. From an evolutionary perspective, it is therefore puzzling that the tool use behaviour of their closest living primate relative, the bonobo, Pan paniscus, has been described as particularly poor. However, only a small number of bonobo groups have been studied in the wild and only over comparably short periods. Here, we show that captive bonobos and chimpanzees are equally diverse tool-users in most contexts. Our observations illustrate that tool use in bonobos can be highly complex and no different from what has been described for chimpanzees. The only major difference in the chimpanzee and bonobo data was that bonobos of all age–sex classes used tools in a play context, a possible manifestation of their neotenous nature. We also found that female bonobos displayed a larger range of tool use behaviours than males, a pattern previously described for chimpanzees but not for other great apes. Our results are consistent with the hypothesis that the female-biased tool use evolved prior to the split between bonobos and chimpanzees.
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Whistance, L. K., Sinclair, L. A., Arney, D. R., & Phillips, C. J. C. (2009). Trainability of eliminative behaviour in dairy heifers using a secondary reinforcer. Appl. Anim. Behav. Sci., 117(3-4), 128–136.
Abstract: Soiled bedding influences cleanliness and disease levels in dairy cows and there is no evidence of an inherent latrine behaviour in cattle. If cows were trained to use a concrete area of the housing system as a latrine, a cleaner bed could be maintained. Thirteen group-housed, 14-16-month-old Holstein-Friesian heifers, were clicker trained with heifer-rearing concentrate pellets as a reward. Training was carried out in four phases. (Phase 1) Association of feed reward with clicker, criterion: 34/40 correct responses. (Phase 2) Simple task (nose-butting a disc) to reinforce phase 1 association, criterion: 17/20 correct responses. (Phase 3) Association of eliminative behaviour with reward where criterion was four sessions with only one incorrect response: criteria for each heifer in phases 1-3 were set using binomial tests. (Phase 4) Shaping eliminative behaviour to occur on concrete. Possible responses were, eliminating on concrete (C) or straw (S), or moving from one substrate to another immediately before eliminating: C --> S, S --> C. Heifers were rewarded for the desired behaviours C and S --> C and ignored when S and C --> S occurred. If learning was achieved, C should increase as C --> S decreased and S --> C should increase as S decreased: tested with Spearman rank correlations. All heifers achieved criterion by day 4 of phase 1 (P = 0.001); day 1 of phase 2 (P = 0.001) and day 10 of phase 3 (P < 0.009). Responses changed throughout phase 3 beginning with (i) looking at the trainer whilst voiding then moving to trainer after the click, and later including (ii) moving to trainer immediately before- or (iii) during voiding. No relationship was found between S and S --> C (rs = -0.14; P = 0.63) or C and C --> S (rs = -0.33; P = 0.25). All group members eliminated more often on concrete (580) than on straw (141) but four heifers with consistently longer lying bouts also showed more C --> S before lying down (Mann-Whitney, P = 0.007). The present study is believed to be the first reported work to show that cattle can be trained to show an awareness of their own eliminative behaviour. This was not successfully shaped to latrine behaviour, however, and it is suggested that floor type may not have been a sufficiently salient cue. Voiding on straw occurred largely with response C --> S (0.73) and general behaviour suggested that this was strongly linked to lying patterns of individual heifers.
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Hewitt, S. E., Macdonald, D. W., & Dugdale, H. L. (2009). Context-dependent linear dominance hierarchies in social groups of European badgers, Meles meles. Anim. Behav., 77(1), 161–169.
Abstract: A social hierarchy is generally assumed to exist in those mammalian societies in which the costs and benefits of group living are distributed unevenly among group members. We analysed infrared closed-circuit television footage, collected over 3 years in Wytham Woods, Oxfordshire, to test whether social groups of European badgers have dominance hierarchies. Analysis of directed aggression between dyads revealed linear dominance hierarchies in three social-group-years, but patterns within social groups were not consistent across years. Dominance hierarchies were significantly steeper than random in five out of six social-group-years. In those social-group-years where a linear hierarchy was determined, there was an effect of sex on dominance rank, with females gaining significantly higher rank than males in two social-group-years. Overall, rank was not related to age, nor did it appear to affect the likelihood of an individual being wounded, or an individual's breeding status. The latter resulted from nonorthogonality between sex and breeding status, as there were only two breeding males. Overall, hierarchies were primarily dominated by breeding females, and may occur when breeding competition arises. Relatedness, unreciprocated allogrooming and sequential allomarking were not consistently related to levels of directed aggression across social-group-years. We suggest that dominance structures within European badger groups may be context dependent, with future study required to complete our understanding of where, and when, they arise.
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VanDierendonck, M. C., de Vries, H., Schilder, M. B. H., Colenbrander, B., & Þorhallsdóttir, A. G. and S., H. (2009). Interventions in social behaviour in a herd of mares and geldings. Appl. Anim. Behav. Sci., 116(1), 67–73.
Abstract: Social dynamics and maintenance of social cohesion were studied by analysing social interventions in two groups of horses consisting of adult mares, their offspring, adult geldings and sub-adults. The animals were observed for a total of 1316 h. All relevant dyadic and triadic social interactions, including initial behaviour, possible intervention and outcome, were recorded. The main question was: do horses use interventions in affiliative interactions to safeguard their social network? Horses were significantly more likely to intervene in allogrooming or play interactions that involved a preferred partner. The stronger the preferred association in allogrooming, the higher the likelihood the intervener took over allogrooming with an initial dyad member. Interveners originating from two newly introduced groups (n = 3 and 5), intervened significantly more often when a member of their own group allogroomed with an unfamiliar horse. In play, no correlation with unfamiliarity was found. Overall, the intervening horses stopped more than half of the initial allogrooming interactions, and a third of all interactions. Therefore, social facilitation cannot sufficiently explain interference behaviour. This study shows that maintaining relationships with preferred partners is important to horses and has implications for equine husbandry and management.
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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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Broom, D. M., Sena, H., & Moynihan, K. L. (2009). Pigs learn what a mirror image represents and use it to obtain information. Anim. Behav., 78(5), 1037–1041.
Abstract: Mirror usage has been taken to indicate some degree of awareness in animals. Can pigs, Sus scrofa, obtain information from a mirror? When put in a pen with a mirror in it, young pigs made movements while apparently looking at their image. After 5 h spent with a mirror, the pigs were shown a familiar food bowl, visible in the mirror but hidden behind a solid barrier. Seven out of eight pigs found the food bowl in a mean of 23 s by going away from the mirror and around the barrier. Naïve pigs shown the same looked behind the mirror. The pigs were not locating the food bowl by odour, did not have a preference for the area where the food bowl was and did not go to that area when the food bowl was visible elsewhere. To use information from a mirror and find a food bowl, each pig must have observed features of its surroundings, remembered these and its own actions, deduced relationships among observed and remembered features and acted accordingly. This ability indicates assessment awareness in pigs. The results may have some effects on the design of housing conditions for pigs and may lead to better pig welfare.
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Hartmann, E., Christensen, J. W., & Keeling, L. J. (2009). Social interactions of unfamiliar horses during paired encounters: Effect of pre-exposure on aggression level and so risk of injury. Appl. Anim. Behav. Sci., 121(3-4), 214–221.
Abstract: Group housing of horses is not widely applied in practice despite the welfare advantages of keeping animals socially rather than individually. In particular, concerns have been raised about the possible increased risk of injury and how to introduce a new horse into an established group. This study investigated two hypotheses: (1) pre-exposure of young horses in neighbouring boxes reduces the frequency of aggressive interactions when the same horses are subsequently put together in a paddock compared to horses without this previous box experience, (2) the occurrence of aggressive behaviour, in particular contact aggression in the paddock can be predicted after observing the horses' social interactions in neighbouring boxes. Danish Warmblood mares (n = 20), 2 years old, were kept in two groups of 10 horses. In total, 60 encounters were arranged whereby each horse was confronted pair-wise with six horses from the other group, three according to each treatment: treatment I--box (B) and subsequent paddock meeting (BP), and treatment II--only paddock meeting (P). Horses met in neighbouring boxes for 5 min and together in the same paddock for 10 min. The frequencies of aggressive and non-aggressive interactions were analysed from video recordings. Total aggression levels between BP and P did not differ, but [`]contact aggression', i.e. bite, kick, strike, push, tended to be lower in BP compared to P (median BP = 1, P = 2; p = 0.083) and there were less bites in BP than P (median BP = 0, P = 1; p = 0.050). Frequencies of [`]non-aggressive' interactions, e.g. friendly approach, nasal sniff, were lower in BP than P (median BP = 2.5, P = 10; p < 0.01). Results further revealed that [`]bite threat' performed in boxes correlated with [`]contact aggression' in the paddock (r = 0.46, p = 0.011). In conclusion, pre-exposure of young horses in neighbouring boxes may reduce [`]contact aggression', especially biting, in the paddock and [`]bite threat' shown in boxes may help to predict contact aggression when horses are later turned out together. The reduced non-aggressive interactions in the paddock in the BP test were probably a consequence of horses having exchanged these behaviours in the preceding B test. Exposing young horses in boxes next to each other may be a helpful tool before mixing them because horses meet in a safe environment that could assist in reducing the type of aggression where horses are most at risk of being injured.
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Ward, C., Trisko, R., & Smuts, B. B. (2009). Third-party interventions in dyadic play between littermates of domestic dogs, Canis lupus familiaris. Anim. Behav., 78(5), 1153–1160.
Abstract: Interventions occur when animals interfere in competitive interactions between two or more individuals. Interveners can alter the nature of the ongoing interaction by targeting one party (attacking, biting) and supporting the other. Three theories have been proposed to account for intervention behaviour: kin selection, reciprocity and direct benefits. The kin selection hypothesis predicts that interveners will selectively support relatives over nonrelatives; the reciprocity hypothesis predicts that when intervener [`]A' supports individual [`]B', later [`]B' will intervene and support [`]A'; and the direct benefits hypothesis predicts that target/support patterns should serve the immediate interests of the intervener. We tested the reciprocity and direct benefits hypotheses by exploring third-party interventions in play fighting among littermates of domestic dogs. Interveners in dyadic play did not preferentially target or support preferred playmates of the intervener. Interveners targeted the dog in the losing role at the time of the intervention, and they did not show reciprocity in support. Taken together, these last two findings suggest that littermates benefit directly and use interventions opportunistically to practise offence behaviours directed at littermates already behaving subordinately. Opportunities to practise targeting in a playful setting may help structure dominance relationships among littermates. Additionally, the tendency for puppies to do what the other is doing (target the dog in the losing role) may pave the way for synchronizing cooperative behaviours during group hunting and territorial defence. The types of behaviours used to intervene changed over development, but the outcome following an intervention remained stable.
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