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Veissier, I., Boissy, A., Nowak, R., Orgeur, P., & Poindron, P. (1998). Ontogeny of social awareness in domestic herbivores. Appl. Anim. Behav. Sci., 57(3-4), 233–245.
Abstract: It is now well established that domestic animals construct responses to their environment that depend on experience and on integration of several features of the environment, including social partners. This ability to be aware of the environment is not fully developed at birth but improves and varies through the animal's life. This topic is discussed on the basis of social processes in sheep and cattle. Social relationships of an animal with its conspecifics develop with age; they do not merely depend on pre-programmed behaviours but rely at least in part on learning of characteristics of the partners. Soon after birth, a strong preferential bond establishes with the dam then to a lesser extent, the young associates to other members of the flock, especially other young. The attractiveness of the group varies later in life due to external events or to physiological state: the abrupt separation from the dam at artificial weaning strengthens bonds between peers, whereas around parturition, females are less disturbed by isolation from the group. More recently, the awareness of social partners has been described in non-social contexts: the animal modifies its responses to events according to the presence of partners, and also to their emotional state and behaviour. The effects of partners seem to depend on their relationship with the animal and also on the social motivation of that animal, which both vary during its life. We recommend study of the ontogeny of awareness using the model of social influences.
Keywords: Animal; Environment; Relationship
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De Pasquale, A., Ingala, A., Innella, G., Luigiano, G., Malara, L., & Panzera, M. (2008). The influence of the enriched environment on the reactivity of the precociously handled foals (Equus caballus L.). In IESM 2008.
Abstract: In a preliminary study, we evaluated the effect of precocious handling (at birth, 10, 30 and 60 days) and enriched environment on foal. Two experimental groups were created:
- 3 foals not handled and stabled in semi-enriched environment (Group A). - 6 foals handled and stabled in an enriched environment (Group B). All nine foals were tested with a novel object test (umbrella) at three months of age, to assess the Heart Rate (HR) values measured by a telemetric heart rate monitor (Polar Horse Trainer), during opening, touching and closing of the umbrella. The statistical analysis carried out by means of the Mann-Whitney test showed lower HR values of the foals of group B (P<0.05). Furthermore we have investigated 10 foals born between 2006 and 2008 to study the influence of enriched environment and precocious handling on behavioural responsiveness. The foals were housed on a farm which ensured an enriched environment and made social intra and interspecific interactions easier, alias autoshaping. They were submitted to: - Handling within 24 hours from birth. - Handling and reactivity test (arena test) executed at 10, 30 and 60 days. The temporal correlation was studied among ages and baseline HR values, using the Spearman"s test, to assess the beginning of neurovegetative HR control. In fact statistically significant differences were obtained (r = -0.431; P<0,02). Temporal values of obtained HR baseline, using the Wilcoxon test, showed lower values at 60 days. The comparison was significant among mean and max baseline HR values of 30 vs 60 and 10 vs 60 (P<0.05), while no differences were observed during the reactivity test. This shows that adequate conditions of management associated to a precocious and continuous handling allow the foals to maintain their natural investigative behaviour disappearing fear and flight reactions. |
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Hostetter, A. B., Cantero, M., & Hopkins, W. D. (2001). Differential use of vocal and gestural communication by chimpanzees (Pan troglodytes) in response to the attentional status of a human (Homo sapiens). J. Comp. Psychol., 115(4), 337–343.
Abstract: This study examined the communicative behavior of 49 captive chimpanzees (Pan troglodytes), particularly their use of vocalizations, manual gestures, and other auditory- or tactile-based behaviors as a means of gaining an inattentive audience's attention. A human (Homo sapiens) experimenter held a banana while oriented either toward or away from the chimpanzee. The chimpanzees' behavior was recorded for 60 s. Chimpanzees emitted vocalizations faster and were more likely to produce vocalizations as their 1st communicative behavior when a human was oriented away from them. Chimpanzees used manual gestures more frequently and faster when the human was oriented toward them. These results replicate the findings of earlier studies on chimpanzee gestural communication and provide new information about the intentional and functional use of their vocalizations.
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Jacobs, A., Maumy, M., & Petit, O. (2008). The influence of social organisation on leadership in brown lemurs (Eulemur fulvus fulvus) in a controlled environment. Behav. Process., 79(2), 111–113.
Abstract: Studies on leadership during group movements in several lemur species showed that females were responsible for the travelling choices concerning time and direction. Interestingly, in these species females are dominant over males. We investigated the influence of social organisation upon leadership processes by studying a lemur species in which social organisation is characterized by the absence of female dominance: the brown lemur (Eulemur fulvus fulvus). The study was conducted on a semi-free ranging group of 11 individuals and the analysis performed on 69 group movements showed that all the individuals could initiate a group movement. In 34 cases, the whole group moved. There was no significant difference in the number of start attempts or in the number of group members involved from one initiator to another. Moreover, there was no effect of sex or age of the initiator on the number of individuals following it or on the speed of the joining process. Therefore, the leadership observed is widely distributed to all group members. These results support the hypothesis of an influence of social organisation upon the decision-making processes but still remain to be studied in a more relevant ecological context.
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Potts, R. (1998). Variability selection in hominid evolution. Evol. Anthropol., 7(3), 81–96.
Abstract: Variability selection (abbreviated as VS) is a process considered to link adaptive change to large degrees of environment variability. Its application to hominid evolution is based, in part, on the pronounced rise in environmental remodeling that took place over the past several million years. The VS hypothesis differs from prior views of hominid evolution, which stress the consistent selective effects associated with specific habitats or directional trends (e.g., woodland, savanna expansion, cooling). According to the VS hypothesis, wide fluctuations over time created a growing disparity in adaptive conditions. Inconsistency in selection eventually caused habitat-specific adaptations to be replaced by structures and behaviors responsive to complex environmental change. Key hominid adaptations, in fact, emerged during times of heightened variability. Early bipedality, encephalized brains, and complex human sociality appear to signify a sequence of VS adaptations—i.e., a ratcheting up of versatility and responsiveness to novel environments experienced over the past 6 million years. The adaptive results of VS cannot be extrapolated from selection within a single environmental shift or relatively stable habitat. If some complex traits indeed require disparities in adaptive setting (and relative fitness) in order to evolve, the VS idea counters the prevailing view that adaptive change necessitates long-term, directional consistency in selection. © 1998 Wiley-Liss, Inc.
Keywords: variability selection; hominids; environment; adaptation; natural selection; evolution
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Lee, R. D. (2003). Rethinking the evolutionary theory of aging: transfers, not births, shape senescence in social species. Proc Natl Acad Sci U S A, 100(16), 9637–9642.
Abstract: The classic evolutionary theory of aging explains why mortality rises with age: as individuals grow older, less lifetime fertility remains, so continued survival contributes less to reproductive fitness. However, successful reproduction often involves intergenerational transfers as well as fertility. In the formal theory offered here, age-specific selective pressure on mortality depends on a weighted average of remaining fertility (the classic effect) and remaining intergenerational transfers to be made to others. For species at the optimal quantity-investment tradeoff for offspring, only the transfer effect shapes mortality, explaining postreproductive survival and why juvenile mortality declines with age. It also explains the evolution of lower fertility, longer life, and increased investments in offspring.
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Li, C., Jiang, Z., Tang, S., & Zeng, Y. (2007). Influence of enclosure size and animal density on fecal cortisol concentration and aggression in Pere David's deer stags. Gen Comp Endocrinol, 151(2), 202–209.
Abstract: We investigated the impact of enclosure size and animal density on behavior and adrenocortical secretion in Pere David's deer in Dafeng Nature Reserve, China. From February 15 to April 16 in 2004, we conducted two experiments. First, we studied maintenance behavior and conflict behavior of Pere David's deer stags in a large enclosure (200 ha) with low animal density (0.66 deer/ha) and a small display pen (0.75 ha) with high animal density (25.33 deer/ha). The maintenance behavior we recorded included standing, locomotion, foraging and rest. During the behavioral observations, we collected fresh voided fecal samples from the stags periodically, and analyzed the fecal cortisol concentrations in those samples using radioimmunoassay technique. Second, we monitored the fecal cortisol concentrations of one group of stags (12 deer lived in an enclosure of 100 ha) before and after transferred into a small pen (0.5 ha). We found that in the first experiment: (1) there were significant differences in standing and rest whereas no significant differences of locomotion and foraging between the free-ranging group and the display group; (2) frequency of conflict behavior in the display group was significantly higher than those in the free-ranging group; and (3) fecal cortisol concentration of the display group (326.17+/-16.98 ng/g dry feces) was significantly higher than that of the free-ranging group (268.98+/-15.21 ng/g dry feces). In the second experiment, there was no significant difference of the fecal cortisol concentrations among sampling days, but the mean fecal cortisol concentration of the day after transferring (337.46+/-17.88 ng/g dry feces) was significantly higher than that of the day before transferring (248.44+/-7.99 ng/g dry feces). Comparison with published findings, our results indicated that enclosure size and animal density affect not only behaviors, but also adrenocortical secretion in Pere David's deer. Small living space with high animal density may impose physiological stress to captive Pere David's deer. Moreover, long-term physiological stress and increase of conflict behavior may subsequently affect survival and reproduction of the deer.
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Carter, C., & Greening, L. Auditory stimulation of the stabled equine; the effect of different music genres on behaviour.
Abstract: Having a radio playing during the daytime at some equine establishments is common practice, but few studies have investigated whether particular music genres could be enriching for stabled horses or whether they may be perceived as aversive. This study aimed to establish whether behavioural responses differed when exposed to musical genres (Classical, Country, Jazz and Rock) and when compared to a control (no music). Eight Thoroughbred geldings (age range 8-10 years, average 8.9 years) were exposed to four musical environments and the control environment (no music) and observed in their usual stable, using instantaneous focal sampling every thirty seconds according to a pre-determined ethogram. Each horse was exposed to each genre for an hour in total, at a time when there was no human traffic or interference on the yard. All horses had been stabled for three hours before the study began. The association between genres and behavioural frequencies recorded for each environment was tested using Fisher’s Exact test of association (P<0.01), IBM SPSS21. No statistically significant associations (P=1.0) were recorded between alert or relax behaviours in Country, Classical, and Control environments. Significant associations (P<0.001) between frequency of alert behaviours and Jazz and Rock environments were noted. The latter genres appeared the most aversive which may be due to fast tempo and minor key, especially in the Jazz piece used. Country and Classical genres were slow tempo with a major key and appeared to result in more restful behaviours than Jazz or Rock. Further research is needed to; assess whether music could be used as an enriching tool, and investigate equine emotional capabilities to understand the emotional effects of music. Future studies could also consider how music impacts upon the behaviour of the human handler and whether this influences equine behaviour.
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Löckener, S., Reese, S., Erhard, M., & Wöhr, A. - C. (2016). Pasturing in herds after housing in horseboxes induces a positive cognitive bias in horses. Journal of Veterinary Behavior: Clinical Applications and Research, 11, 50–55.
Abstract: Abstract Horses are kept in various housing systems, for example, with conspecifics in horse pens or singly in horseboxes, with or without pasturing. To provide appropriate living conditions for horses, it is necessary to know in which conditions they feel well or unwell. Here, a cognitive bias assessment provides information about an individual's affective state and its well-being. When a positive affective state prevails, animals tend to judge optimistically in ambiguous situations. When a negative affective state prevails, animals judge pessimistically in unclear situations. In the present study, we trained horses on a spatial discrimination task and evaluated their judgment of ambiguous locations when they had access to pastures and contact to conspecifics versus when they were kept singly in horseboxes. Ten days of pasturing and contact with conspecifics after being kept singly in horseboxes for 6 months induced a positive cognitive bias in the horses. We suggest that horses need to act out certain behaviors like exploration, social interaction, play, or grooming to fulfill their needs. After a time in which they were individually in horseboxes without pasturing and access to the herd, they seem to have a positive cognitive bias once they have access to pastures and conspecifics. This positive cognitive bias effect seems to disappear over time, as horses appear to adapt to the circumstances.
Keywords: judgment bias; affect; environmental enrichment; well-being; discrimination task; horse
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López-Bao, J. V., Sazatornil, V., Llaneza, L., & Rodríguez, A. (2013). Indirect Effects on Heathland Conservation and Wolf Persistence of Contradictory Policies that Threaten Traditional Free-Ranging Horse Husbandry. Conservation Letters, 6(6), 448–455.
Abstract: Conservation agencies within the European Union promote the restoration of traditional land uses as a cost-effective way to preserve biodiversity outside reserves. Although the European Union pursues the integration of the environment into strategic decision-making, it also dictates sectoral policies that may damage farmland biodiversity. We illustrate this point by outlining the socioeconomic factors that allow the persistence of traditional free-ranging horse husbandry in Galicia, northwestern Spain. Free-ranging Galician mountain ponies provide ecological and socioeconomic services including the prevention of forest fires, the maintenance of heathlands and wolves, and the attenuation of wolf-human conflicts. This traditional livestock system may have persisted because it entails negligible costs for farmers. Wolf predation upon Galician mountain ponies does not threaten farmer's economies and seems to be tolerated better than attacks to more valuable stock. Recently, European Union's regulations on animal welfare, carcass management, or meat production put new economic and administrative burdens on farmers, make free-ranging horse rearing economically unsustainable, and incentivize its abandonment. The aim of the European Union to integrate environmental policies may be successful to preserve farmland biodiversity only through careful anticipation of the side effects of apparently unrelated regulations on the fragile equilibrium that sustain traditional land uses.
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