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Allen, C. (2006). Transitive inference in animals: Reasoning or conditioned associations? In S. Hurley, & M. Nudds (Eds.), Rational Animals? (pp. 175–186). Oxford: Oxford University Press.
Abstract: It is widely accepted that many species of nonhuman animals appear to engage in transitive inference,
producing appropriate responses to novel pairings of non-adjacent members of an ordered series
without previous experience of these pairings. Some researchers have taken this capability as
providing direct evidence that these animals reason. Others resist such declarations, favouring instead
explanations in terms of associative conditioning. Associative accounts of transitive inference have
been refined in application to a simple 5-element learning task that is the main paradigm for
laboratory investigations of the phenomenon, but it remains unclear how well those accounts
generalise to more information-rich environments such as social hierarchies which may contain scores
of individuals, and where rapid learning is important. The case of transitive inference is an example of
a more general dispute between proponents of associative accounts and advocates of more cognitive
accounts of animal behaviour. Examination of the specific details of transitive inference suggests
some lessons for the wider debate.
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Rosell, F., & Sanda, J. I. (2006). Potential risks of olfactory signaling: the effect of predators on scent marking by beavers. Behav. Ecol., 17(6), 897–904.
Abstract: Mammals scent mark their territories to advertise occupancy and ownership. However, signaling with scent for territorial defense can have a negative effect by advertising an individual's presence and location to predators. In this study, we measured responses to a simulated territorial intrusion by conspecific adult male Eurasian beavers (Castor fiber) either in the localized presence or in the absence of odor of a predator to test the hypothesis that the territorial defense of free-living beavers would be disrupted by the presence of predation risk in their natural environment. We predicted that beavers would significantly reduce their willingness to countermark intruder's scent in the presence of the scent of predators (wolf [Canis lupus] and lynx [Lynx lynx]), compared with a control (no odor), as responses are in general stronger to predator scent marks than nonpredator scent. Therefore, we also predicted that the effects of nonpredatory mammal scent (neophobic control) (eland [Taurotragus oryx] and horse [Equus cabalus]) are to be expected somewhere in between the effects of the predator odor and a control. Our results suggest that both predator and nonpredator scents reduce beavers response to a simulated intruder's scent mounds and therefore disrupt their territorial defense. However, predator scent had a stronger effect than nonpredator scent. Beavers may therefore be at great risk on territories with predators present because of the trade-off between predator avoidance and territorial defense. Our study demonstrates the potential of predation risk as a powerful agent of counterselection on olfactory signaling behavior.
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Pluhácek, j., Bartos, L., & Víchová, J. (2006). Variation In Incidence Of Male Infanticide Within Subspecies Of Plains Zebra (Equus Burchelli). Journal of Mammalogy, 87(1), 35–40.
Abstract: Social organization seems to determine the occurrence of male infanticide in equids. Although, no information concerning social organization of the maneless zebra (Equus burchelli borensis) has been available, we presumed that the occurrence of infanticide would be the same across all subspecies of plains zebra. We examined the occurrence of this phenomenon in 9 herds of 4 subspecies: the maneless zebra, Grant's zebra (E. burchelli boehmi), Chapmann's zebra (E. b. chapmanni), and the Damara zebra (E. b. antiquorum) at 4 zoos. The probability of a foal's death was affected by the presence of a new male and subspecies. Except for the maneless zebra, all subspecies showed existence of male infanticide. We found no occurrence of male infanticide in maneless zebras, which suggests a different social system. This would also support the subspecific status of the maneless zebra.
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Keay, J. M., Singh, J., Gaunt, M. C., & Kaur, T. (2006). Fecal glucocorticoids and their metabolites as indicators of stress in various mammalian species: a literature review. J Zoo Wildl Med, 37(3), 234–244.
Abstract: Conservation medicine is a discipline in which researchers and conservationists study and respond to the dynamic interplay between animals, humans, and the environment. From a wildlife perspective, animal species are encountering stressors from numerous sources. With the rapidly increasing human population, a corresponding increased demand for food, fuel, and shelter; habitat destruction; and increased competition for natural resources, the health and well-being of wild animal populations is increasingly at risk of disease and endangerment. Scientific data are needed to measure the impact that human encroachment is having on wildlife. Nonbiased biometric data provide a means to measure the amount of stress being imposed on animals from humans, the environment, and other animals. The stress response in animals functions via glucocorticoid metabolism and is regulated by the hypothalamic-pituitary-adrenal axis. Fecal glucocorticoids, in particular, may be an extremely useful biometric test, since sample collection is noninvasive to subjects and, therefore, does not introduce other variables that may alter assay results. For this reason, many researchers and conservationists have begun to use fecal glucocorticoids as a means to measure stress in various animal species. This review article summarizes the literature on many studies in which fecal glucocorticoids and their metabolites have been used to assess stress levels in various mammalian species. Variations between studies are the main focus of this review. Collection methods, storage conditions, shipping procedures, and laboratory techniques utilized by different researchers are discussed.
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Deecke, V. B. (2006). Studying Marine Mammal Cognition in the Wild: A Review of Four Decades of Playback Experiments. Aquatic Mammals, 32, 461–482.
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Balakrishnan, G., Hu, Y., & Spiro, T. G. (2006). Temperature-jump apparatus with Raman detection based on a solid-state tunable (1.80-2.05 microm) kHz optical parametric oscillator laser. Appl Spectrosc, 60(4), 347–351.
Abstract: The operating characteristics of a pulsed (10 ns) tunable near-infrared (NIR) laser source are described for temperature-jump (T-jump) applications. A Q-switched Nd:YLF laser (approximately 10 ns pulses) with a 1 kHz repetition rate is used to pump a potassium titanyl arsenate (KTA) crystal-based optical parametric oscillator (OPO), producing approximately 1 mJ NIR pulses that are tunable (1.80-2.05 microm) across the 1.9 microm vibrational overtone band of water. This T-jump source has been coupled to a deep ultraviolet (UV) probe laser for Raman studies of protein dynamics. T-jumps of up to 30 degrees C, as measured via the O-H stretching Raman band of water, are readily achieved. Application to cytochrome c unfolding is demonstrated.
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Arnold, W., Ruf, T., & Kuntz, R. (2006). Seasonal adjustment of energy budget in a large wild mammal, the Przewalski horse (Equus ferus przewalskii) II. Energy expenditure. J Exp Biol, 209(Pt 22), 4566–4573.
Abstract: Many large mammals show pronounced seasonal fluctuations of metabolic rate (MR). It has been argued, based on studies in ruminants, that this variation merely results from different levels of locomotor activity (LA), and heat increment of feeding (HI). However, a recent study in red deer (Cervus elaphus) identified a previously unknown mechanism in ungulates--nocturnal hypometabolism--that contributed significantly to reduced energy expenditure, mainly during late winter. The relative contribution of these different mechanisms to seasonal adjustments of MR is still unknown, however. Therefore, in the study presented here we quantified for the first time the independent contribution of thermoregulation, LA and HI to heart rate (f(H)) as a measure of MR in a free-roaming large ungulate, the Przewalski horse or Takhi (Equus ferus przewalskii Poljakow). f(H) varied periodically throughout the year with a twofold increase from a mean of 44 beats min(-1) during December and January to a spring peak of 89 beats min(-1) at the beginning of May. LA increased from 23% per day during December and January to a mean level of 53% per day during May, and declined again thereafter. Daily mean subcutaneous body temperature (T(s)) declined continuously during winter and reached a nadir at the beginning of April (annual range was 5.8 degrees C), well after the annual low of air temperature and LA. Lower T(s) during winter contributed considerably to the reduction in f(H). In addition to thermoregulation, f(H) was affected by reproduction, LA, HI and unexplained seasonal variation, presumably reflecting to some degree changes in organ mass. The observed phase relations of seasonal changes indicate that energy expenditure was not a consequence of energy uptake but is under endogenous control, preparing the organism well in advance of seasonal energetic demands.
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van Breda, E. (2006). A non-natural head-neck position (rollkur) during training results in less acute stress in elite trained dressage horses. Journal of Applied Animal Welfare Science, 9(1), 59–64.
Abstract: This study measured parameters of stress in recreational, trained horses (REC; n = 7) and elite (International Grand Prix level) trained, dressage horses (DRES; n = 5). The training of the DRES horses uses an unnatural head?neck position (Rollkur), whereas in the REC horses such training techniques are not common. The study measured stress by using heart rate variability analysis for 30 min postfeeding in the morning and 30 min postexercise after a morning training session. The study found no significant difference at rest between the REC and DRES horses. During the posttraining measurements, however, the DRES horses showed, among others, a less sympathetic and increased parasympathetic dominance. These results suggest that DRES horses tend to have less acute stress than do REC horses postexercise. The findings of this study suggest maintaining the health and well-being of DRES horses despite nonnatural, biomechanical positions.
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Chase, I. D. (2006). Music notation: a new method for visualizing social interaction in animals and humans. Front Zool, 3, 18.
Abstract: ABSTRACT: BACKGROUND: Researchers have developed a variety of techniques for the visual presentation of quantitative data. These techniques can help to reveal trends and regularities that would be difficult to see if the data were left in raw form. Such techniques can be of great help in exploratory data analysis, making apparent the organization of data sets, developing new hypotheses, and in selecting effects to be tested by statistical analysis. Researchers studying social interaction in groups of animals and humans, however, have few tools to present their raw data visually, and it can be especially difficult to perceive patterns in these data. In this paper I introduce a new graphical method for the visual display of interaction records in human and animal groups, and I illustrate this method using data taken on chickens forming dominance hierarchies. RESULTS: This new method presents data in a way that can help researchers immediately to see patterns and connections in long, detailed records of interaction. I show a variety of ways in which this new technique can be used: (1) to explore trends in the formation of both group social structures and individual relationships; (2) to compare interaction records across groups of real animals and between real animals and computer-simulated animal interactions; (3) to search for and discover new types of small-scale interaction sequences; and (4) to examine how interaction patterns in larger groups might emerge from those in component subgroups. In addition, I discuss how this method can be modified and extended for visualizing a variety of different kinds of social interaction in both humans and animals. CONCLUSION: This method can help researchers develop new insights into the structure and organization of social interaction. Such insights can make it easier for researchers to explain behavioural processes, to select aspects of data for statistical analysis, to design further studies, and to formulate appropriate mathematical models and computer simulations.
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Meunier, H., Leca, J. B., Deneubourg, J. L., & Petit, O. (2006). Group movement decisions in capuchin monkeys: the utility of an experimental study and a mathematical model to explore the relationship between individual and collective behaviours. Behaviour, 143, 1511–1527.
Abstract: In primate groups, collective movements are typically described as processes dependent on leadership mechanisms. However, in some species, decision-making includes negotiations and distributed leadership. These facts suggest that simple underlying processes may explain certain decision mechanisms during collective movements. To study such processes, we have designed experiments on white-faced capuchin monkeys (Cebus capucinus) during which we provoked collective movements involving a binary choice. These experiments enabled us to analyse the spatial decisions of individuals in the group. We found that the underlying process includes anonymous mimetism, which means that each individual may influence all members of the group. To support this result, we created a mathematical model issued from our experimental data. A totally anonymous model does not fit perfectly with our experimental distribution. A more individualised model, which takes into account the specific behaviour of social peripheral individuals, revealed the validity of the mimetism hypothesis. Even though white-faced capuchins have complex cognitive abilities, a coexistence of anonymous and social mechanisms appears to influence their choice of direction during collective movements. The present approach may offer vital insights into the relationships between individual behaviours and their emergent collective acts.
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