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Hausberger, M., Bruderer, C., Le Scolan, N., & Pierre, J. - S. (2004). Interplay between environmental and genetic factors in temperament/personality traits in horses (Equus caballus). J Comp Psychol, 118(4), 434–446.
Abstract: The aim of the present study was to broach the question of the relative influence of different genetic and environmental factors on different temperament/personality traits of horses (Equus caballus). The researchers submitted 702 horses to standardized experimental tests and investigated 9 factors, either genetic or environmental. Genetic factors, such as sire or breed, seemed to influence more neophobic reactions, whereas environmental factors, such as the type of work, seemed to play a more dominant role in reactions to social separation or learning abilities. Additive effects were evident, showing how environmental factors may modulate behavioral traits. This study constitutes a first step toward understanding the relative weights of genetic factors and how the environment may intervene in determining individual behavioral characteristics.
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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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Stoinski, T. S., & Whiten, A. (2003). Social learning by orangutans (Pongo abelii and Pongo pygmaeus) in a simulated food-processing task. J Comp Psychol, 117(3), 272–282.
Abstract: Increasing evidence for behavioral differences between populations of primates has created a resurgence of interest in examining mechanisms of information transfer between individuals. The authors examined the social transmission of information in 15 captive orangutans (Pongo abelii and Pongo pygmaeus) using a simulated food-processing task. Experimental subjects were shown 1 of 2 methods for removing a suite of defenses on an “artificial fruit.” Control subjects were given no prior exposure before interacting with the fruit. Observing a model provided a functional advantage in the task, as significantly more experimental than control subjects opened the fruit. Within the experimental groups, the authors found a trend toward differences in the actual behaviors used to remove 1 of the defenses. Results support observations from the wild implying horizontal transfer of information in orangutans and show that a number of social learning processes are likely to be involved in the transfer of knowledge in this species.
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Dyer, F. C. (2002). Animal behaviour: when it pays to waggle (Vol. 419). |
Menzel, E. W. J. (1971). Communication about the environment in a group of young chimpanzees. Folia Primatol (Basel), 15(3), 220–232. |
Quaresmini, C., Forrester, G. S., Spiezio, C., & Vallortigara, G. (2014). Social environment elicits lateralized behaviors in gorillas (Gorilla gorilla gorilla) and chimpanzees (Pan troglodytes). Journal of Comparative Psychology, 128(3), 276–284.
Abstract: The influence of the social environment on lateralized behaviors has now been investigated across a wide variety of animal species. New evidence suggests that the social environment can modulate behavior. Currently, there is a paucity of data relating to how primates navigate their environmental space, and investigations that consider the naturalistic context of the individual are few and fragmented. Moreover, there are competing theories about whether only the right or rather both cerebral hemispheres are involved in the processing of social stimuli, especially in emotion processing. Here we provide the first report of lateralized social behaviors elicited by great apes. We employed a continuous focal animal sampling method to record the spontaneous interactions of a captive zoo-living colony of chimpanzees (Pan troglodytes) and a biological family group of peer-reared western lowland gorillas (Gorilla gorilla gorilla). We specifically focused on which side of the body (i.e., front, rear, left, right) the focal individual preferred to keep conspecifics. Utilizing a newly developed quantitative corpus-coding scheme, analysis revealed both chimpanzees and gorillas demonstrated a significant group-level preference for focal individuals to keep conspecifics positioned to the front of them compared with behind them. More interestingly, both groups also manifested a population-level bias to keep conspecifics on their left side compared with their right side. Our findings suggest a social processing dominance of the right hemisphere for context-specific social environments. Results are discussed in light of the evolutionary adaptive value of social stimulus as a triggering factor for the manifestation of group-level lateralized behaviors. (PsycINFO Database Record (c) 2016 APA, all rights reserved)
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Doligez, B., Danchin, E., & Clobert, J. (2002). Public information and breeding habitat selection in a wild bird population. Science, 297(5584), 1168–1170.
Abstract: According to the “public information” hypothesis, some animal species may monitor the current reproductive success of conspecifics to assess local habitat quality and to choose their own subsequent breeding site. To test this hypothesis experimentally, we manipulated two components of public information, the mean number of offspring raised locally (“quantity”) and their condition (“quality”), in the collared flycatcher Ficedula albicollis. Immigration rate decreased with local offspring quantity but did not depend on local offspring quality, suggesting that immigrants are deprived of information regarding local quality. Conversely, emigration rate increased both when local offspring quantity or quality decreased, suggesting that residents can use both components of public information.
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Fripp, D., Owen, C., Quintana-Rizzo, E., Shapiro, A., Buckstaff, K., Jankowski, K., et al. (2005). Bottlenose dolphin (Tursiops truncatus) calves appear to model their signature whistles on the signature whistles of community members. Anim. Cogn., 8(1), 17–26.
Abstract: Bottlenose dolphins are unusual among non-human mammals in their ability to learn new sounds. This study investigates the importance of vocal learning in the development of dolphin signature whistles and the influence of social interactions on that process. We used focal animal behavioral follows to observe six calves in Sarasota Bay, Fla., recording their social associations during their first summer, and their signature whistles during their second. The signature whistles of five calves were determined. Using dynamic time warping (DTW) of frequency contours, the calves' signature whistles were compared to the signature whistles of several sets of dolphins: their own associates, the other calves' associates, Tampa Bay dolphins, and captive dolphins. Whistles were considered similar if their DTW similarity score was greater than those of 95% of the whistle comparisons. Association was defined primarily in terms of time within 50 m of the mother/calf pair. On average, there were six dolphins with signature whistles similar to the signature whistles of each of the calves. These were significantly more likely to be Sarasota Bay resident dolphins than non-Sarasota dolphins, and (though not significantly) more likely to be dolphins that were within 50 m of the mother and calf less than 5% of the time. These results suggest that calves may model their signature whistles on the signature whistles of members of their community, possibly community members with whom they associate only rarely.
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Takai, S., Fujimori, T., Katsuzaki, K., & Tsubaki, S. (1987). Ecology of Rhodococcus equi in horses and their environment on horse-breeding farms. Vet Microbiol, 14(3), 233–239.
Abstract: Quantitative culture of R. equi in the feces of dams and foals, in the air of the stalls and in the soil of the paddocks was carried out on three horse-breeding farms during the foaling season. The isolation rates of R. equi from the feces of dams from the 3 farms suddenly increased to approximately 80% at the end of March, when the snow in the paddocks finished melting, and remained at that level during April and May. The mean number of R. equi and the isolation rate of R. equi from the feces of dams on the farms were investigated for 5 weeks before and 5 weeks after delivery. During the 10 weeks, there were no differences in the isolation rate or in the mean number of R. equi from the feces of dams. R. equi was first isolated from the feces of the foals born in February and the middle of March at 3-4 weeks of age, on the other hand, it was first isolated from the feces of foals born in the end of March and April at 1-2 weeks of age. The number of R. equi in the soil collected from the paddocks used by dams during the winter was approximately 10(2)-10(4) g-1 of soil during the experiment. R. equi was isolated from the air in the stalls at the end of March and the number of R. equi in the air increased particularly on dry and windy days.(ABSTRACT TRUNCATED AT 250 WORDS)
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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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