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Austin, N. P., & Rogers, L. J. (2007). Asymmetry of flight and escape turning responses in horses. Laterality, 12(5), 464–474.
Abstract: We investigated whether horses display greater reactivity to a novel stimulus presented in the left compared to the right monocular visual field, and whether a population bias exists for escape turning when the same stimulus was presented binocularly. Domestic horses (N=30) were tested on three occasions by a person opening an umbrella five metres away and then approaching. The distance each horse moved away before stopping was measured. Distance was greatest for approach on the left side, indicating right hemisphere control of flight behaviour, and thus followed the same pattern found previously in other species. When order of monocular presentation was considered, an asymmetry was detected. Horses tested initially on the left side exhibited greater reactivity for left approach, whereas horses tested on the right side first displayed no side difference in reactivity. Perhaps left hemisphere inhibition of flight response allowed horses to learn that the stimulus posed no threat and this information was transferred to the right hemisphere. No population bias existed for the direction of escape turning, but horses that turned to the right when approached from the front were found to exhibit longer flight distances than those that turned to the left.
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Ceacero, F., Landete-Castillejos, T., Garcia, A. J., Estevez, J. A., & Gallego, L. (2007). Kinship Discrimination and Effects on Social Rank and Aggressiveness Levels in Iberian Red Deer Hinds. Ethology, 113(12), 1133–1140.
Abstract: Abstract Kin recognition is a widespread phenomenon that allows individuals to benefit by enhancing their inclusive fitness, and one of its most common forms is reducing aggressiveness towards relatives. We carried out an experiment with Iberian red deer hinds (Cervus elaphus hispanicus) in order to examine kin biases in dominance behaviour and its consequences on social rank. Three enclosed groups (n = 36, 23 and 21, respectively) were monitored during two lactation seasons and social rank hierarchies were assessed by analysing aggressive interactions matrices with Matman 1.1 software. Aggressive interactions between related hinds was significantly smaller than expected (chi2 = 5.02, df = 1, p = 0.025), not only between mother and daughter but also in second and third kinship degrees. Although rates of aggressiveness were similar to data published relating free-ranging C. e. scoticus, aggressive interactions with relatives were significantly smaller (chi2 = 39.0, df = 1, p < 0.001). This reduction of aggressiveness between related hinds was not the result of these hinds having a lower social rank: social rank was only related to age and weight, but not to kinship degree, calf sex or calving date. The decrease of aggressiveness towards first-, second- and third-degree relatives shows a complex kin recognition system in deer. Possible nepotistic roles in lactation include preventing milk thefts by non-kin and disturbing feeding of unrelated hinds.
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Pannozzo, P. L., Phillips, K. A., Haas, M. E., & Mintz, E. M. (2007). Social Monitoring Reflects Dominance Relationships in a Small Captive Group of Brown Capuchin Monkeys (Cebus apella). Ethology, 113(9), 881–888.
Abstract: Abstract In several studies of social monitoring in primates, subordinate animals directed more visual attention toward dominant animals than vice versa. This behavior is thought to enable subordinate animals to avoid conflict. We sought to clarify whether visual attention behavior functions in this manner in a small captive group of brown capuchin monkeys, Cebus apella. We tested the hypothesis that social monitoring is related to dominance status. Dominance status was determined based on the directionality of aggressive behavior, and visual attention was quantified by using focal animal sampling. Subordinate animals directed significantly more visual attention toward others than dominant animals. Subordinate animals also looked more frequently at the animals that attacked them and others the most. The results indicate that social monitoring behavior in this captive group was driven by conflict-avoidance.
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Jonart, L. M., Hill, G. E., & Badyaev, A. V. (2007). Fighting ability and motivation: determinants of dominance and contest strategies in females of a passerine bird. Anim. Behav., 74(6), 1675–1681.
Abstract: The communication of aggressive motivation or fighting ability has important fitness consequences for competing animals. Selection should favour rapid and honest communication between opponents to settle dominance relationships while avoiding prolonged and intense fighting. We investigated factors that influence fighting strategies and contest outcomes in female house finches, Carpodacus mexicanus, specifically focusing on the following questions. (1) What social contexts trigger an aggressive response? (2) Does body size and condition contribute to female fighting ability? (3) Do contextual factors, such as mate presence, nest status, nest proximity, and site experience contribute to fighting motivation? (4) Does contest intensity and duration increase as the differences in fighting ability between opponents decrease? (5) What is the relative contribution of fighting ability and aggressive motivation to the outcome of a contest? We found that aggression was triggered most frequently by female intrusions in the vicinity of nest and by extrapair female intrusions on an established pair. Female fighting and contest outcomes were strongly influenced by body condition and body size, and females were more motivated to initiate fights and won more contests when their mates were present. Females at the later breeding stages and those fighting closer to their nests were dominant and won more fights compared to females at earlier breeding stages or further from their nests. Females initiated a greater proportion of contests against opponents with similar local familiarity and breeding history. Escalated and prolonged contests, while rare, occurred exclusively between females of the most similar body size and condition. When differences in body condition between opponents are not easily perceived, contestants might escalate contests for more reliable assessments of relative fighting ability. Finally, body condition was not a strong determinant of contest outcome in the contexts with easily assessed differences in the resource value (e.g. mate presence), but without these motivational differences, body condition was the ultimate determinant of contest outcomes.
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Valderrabano-Ibarra, C., Brumon, I., & Drummond, H. (2007). Development of a linear dominance hierarchy in nestling birds. Anim. Behav., 74(6), 1705–1714.
Abstract: Theoreticians propose that trained winning and losing are important processes in creating linear animal dominance hierarchies, and experiments have shown that both processes can occur in animals, but their actual roles in creating natural hierarchies are unknown. We described agonism in 18 broods of three blue-footed boobies, Sula nebouxii, a species for which trained winning and losing have been demonstrated, to infer how these processes generate and maintain a natural hierarchy. Ranks in the linear hierarchy that emerged in every brood were initially assigned by asymmetries in age, size and maturity, which led to differences between broodmates in levels of expressed and received aggression and, consequently, to differences in the training of their aggressiveness and submissiveness. Later, ranks appeared to be maintained by the chicks' acquired aggressive and submissive tendencies combined with ongoing effects of persisting differences in size and maturity. Our results suggest that trained winning and trained losing are important in the construction of booby hierarchies but that these two axes of learning are largely independent. Increase in submissiveness occurs over a period of about 10-20 days, and the level of submissiveness reached varies with the amount of aggression received. After training, submissiveness is apparently maintained by a lower level of aggression and increasing use of threats. Threats become increasingly effective as chicks age, but are never as effective as attacks.
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Elfman, L., Brannstrom, J., & Smedje, G. (2007). Detection of Horse Allergen around a Stable. Int Arch Allergy Immunol, 145(4), 269–276.
Abstract: Background: Integrating horse stables with built-up areas may lead to conflicts. Dispersion of horse allergen may become a health risk for allergic people. The aim was to measure the dispersion of horse allergen around a stable, considering wind speed and direction and vegetation. The disturbance of staff at a workplace nearby a stable was investigated. Methods: Air sampling was performed around a stable (32 horses) at distances of 50-500 m in all directions. Sampling was done with a pump and an IOM sampler. Samples were collected at 50 points during all seasons. Horse allergen levels were determined using ELISA. Disturbance by horses was studied with a questionnaire handed to the employees in an office near the stable. Results: The median horse allergen level at the stable entrance was 316 U/m(3), in the horse fields 40 U/m(3) and in the whole source area 16 U/m(3), which declined to <2 U/m(3) at about 50 m from the source area. Downwind of the prevailing winds low levels of horse allergen (2-4 U/m(3)) could sometimes be detected at up to 500 m. The staff, including those allergic to horses, managed to tolerate horses close to the workplace. Conclusions: At low winds horse allergen spread in ambient air about 50 m from the stable and horse fields. At higher winds low allergen levels were sometimes found in open areas up to 500 m from the source area. These levels were similar to those found in the office after moving away from the stable area. The employees did not report more symptoms of allergy or asthma while working close to the stable compared to after the move. Copyright (c) 2007 S. Karger AG, Basel.
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Rietbroek, N. J., Dingboom, E. G., Joosten, B. J. L. J., Eizema, K., & Everts, M. E. (2007). Effect of show jumping training on the development of locomotory muscle in young horses. Am J Vet Res, 68(11), 1232–1238.
Abstract: OBJECTIVE: To investigate whether training for show jumping that is commenced early after birth affects the characteristics of equine locomotory muscle. ANIMALS: 19 Dutch Warmblood horses. PROCEDURES: Horses were assigned to a trained or not trained (control) group. After weaning, training (free jumping [2 d/wk] that was alternated with a 20-minute period of exercise in a mechanical rotating walker [3 d/wk]) was started and continued until horses were 3 years old. Fiber type composition (determined from myosin heavy chain [MyHC] content), fiber area, diffusion index (area supplied by 1 capillary), citrate synthase activity, and Na(+),K(+)-ATPase content were assessed in gluteus medius muscle specimens collected at 0.5, 1, 2, and 3 years. RESULTS: Developmental changes included an increase in MyHC fiber type IIa and a decrease in type IIad; increases in fiber area, diffusion index, and citrate synthase activity; and a decrease in Na(+),K(+)-ATPase content. The MyHC fiber type I and type IId were detected in high and low proportions, respectively. Training increased Na(+),K(+)-ATPase content, but did not affect other variables. CONCLUSIONS AND CLINICAL RELEVANCE: In horses, show jumping training at an early age resulted in increased Na(+),K(+)-ATPase content of the deep portions of the gluteus medius muscle. The lack of training effects on the other muscle characteristics can partly be explained by the fact that an appropriate (aerobic) fiber type composition was already established at training commencement. These data also suggested that the developmental changes in equine muscle represent sufficient adaptation to meet the demands of this specific training.
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Fischhoff, I. R., Sundaresan, S. R., Cordingley, J., & Rubenstein, D. I. (2007). Habitat use and movements of plains zebra (Equus burchelli) in response to predation danger from lions. Behav. Ecol., 18(4), 725–729.
Abstract: Prey species must adapt their behavior to avoid predation. As a key prey item for lions (Panthera leo), plains zebras (Equus burchelli) were expected to respond to immediate threats posed by lions in their area. In addition, zebras were predicted to exhibit behavior tuned to reduce the potential for encounters with lions, by modifying their movement patterns in the times of day and habitats of greatest lion danger. We studied a population of approximately 600 plains zebra living in Ol Pejeta Conservancy, Kenya. We found that zebra abundance on or near a grassland patch was lower if lions had also been observed on that patch during the same day. Predation danger was highest in grassland habitat during the night, when lions were more active. Zebra sightings and global positioning system radio collar data indicated that zebras also reduced their use of grassland at night, instead using more woodland habitat. Zebras moved faster and took sharper turns in grassland at night. It is hypothesized that these more erratic movements assist zebras in avoiding detection or capture by lions.
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Henderson, A. J. Z. (2007). Don't fence me in: managing psychological well being for elite performance horses. J. Appl. Anim. Welf. Sci., 10(4), 309–329.
Abstract: This article posits that stereotypical behavior patterns and the overall psychological well being of today's performance horse could be substantially enhanced with care that acknowledges the relationship between domesticated horses and their forerunners. Feral horses typically roam in stable, social groups over large grazing territories, spending 16-20 hr per day foraging on mid- to poor-quality roughage. In contrast, today's elite show horses live in relatively small stalls, eat a limited-but rich-diet at specific feedings, and typically live in social isolation. Although the horse has been domesticated for more than 6000 years, there has been no selection for an equid who no longer requires an outlet for these natural behaviors. Using equine stereotypies as a welfare indicator, this researcher proposes that the psychological well being of today's performance horse is compromised. Furthermore, the article illustrates how minimal management changes can enhance horses' well being while still remaining compatible with the requirements of the sport-horse industry. The article discusses conclusions in terms of Fraser, Weary, Pajor, and Milligan's “integrative welfare model” (1997).
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Lloyd, N., & Mulcock, J. (2007). Human-animal studies in Australia: Current directions. Society and Animals, 15(1), 1–5.
Abstract: In 2004, Natalie Lloyd and Jane Mulcock initiated the Australian Animals & Society Study Group, a network of social science, humanities and arts scholars that quickly grew to include more than 100 participants. In July 2005, about 50 participants attended the group“s 4-day inaugural conference at the University of Western Australia, Perth. Papers in this issue emerged from the conference. They exemplify the Australian academy”s work in the fields of History, Population Health, Sociology, Geography, and English and address strong themes: human-equine relationships; management of native and introduced animals; and relationships with other domestic, nonhuman animals-from cats and dogs to cattle. Human-Animal Studies is an expanding field in Australia. However, many scholars, due to funding and teaching concerns, focus their primary research in different domains. All authors in this issue-excepting one-are new scholars in their respective fields. The papers represent the diversity and innovation of recent Australian research on human-animal interactions. The authors look at both past and present, then anticipate future challenges in building an effective network to expand this field of study in Australia.
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