Brennan, P. A. (2004). The nose knows who's who: chemosensory individuality and mate recognition in mice. Horm Behav, 46(3), 231–240.
Abstract: Individual recognition is an important component of behaviors, such as mate choice and maternal bonding that are vital for reproductive success. This article highlights recent developments in our understanding of the chemosensory cues and the neural pathways involved in individuality discrimination in rodents. There appear to be several types of chemosensory signal of individuality that are influenced by the highly polymorphic families of major histocompatibility complex (MHC) proteins or major urinary proteins (MUPs). Both have the capability of binding small molecules and may influence the individual profile of these chemosignals in biological fluids such as urine, skin secretions, or saliva. Moreover, these proteins, or peptides associated with them, can be taken up into the vomeronasal organ (VNO) where they can potentially interact directly with the vomeronasal receptors. This is particularly interesting given the expression of major histocompatibility complex Ib proteins by the V2R class of vomeronasal receptor and the highly selective responses of accessory olfactory bulb (AOB) mitral cells to strain identity. These findings are consistent with the role of the vomeronasal system in mediating individual discrimination that allows mate recognition in the context of the pregnancy block effect. This is hypothesized to involve a selective increase in the inhibitory control of mitral cells in the accessory olfactory bulb at the first level of processing of the vomeronasal stimulus.
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Passani M. B., & Blandina P. (2004). The Neuronal Histaminergic System in Cognition. Current Medicinal Chemistry – Central Nervous System Agents, 4, 17–26.
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Emery, N. J., & Clayton, N. S. (2004). The Mentality of Crows: Convergent Evolution of Intelligence in Corvids and Apes. Science, 306(5703), 1903–1907.
Abstract: Discussions of the evolution of intelligence have focused on monkeys and apes because of their close evolutionary relationship to humans. Other large-brained social animals, such as corvids, also understand their physical and social worlds. Here we review recent studies of tool manufacture, mental time travel, and social cognition in corvids, and suggest that complex cognition depends on a “tool kit” consisting of causal reasoning, flexibility, imagination, and prospection. Because corvids and apes share these cognitive tools, we argue that complex cognitive abilities evolved multiple times in distantly related species with vastly different brain structures in order to solve similar socioecological problems.
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McLean, A. N. (2004). The mental processes of the horse and their consequences for training. Animal Welfare Science Centre, .
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Allcroft, D. J., Tolkamp, B. J., Glasbey, C. A., & Kyriazakis, I. (2004). The importance of `memory' in statistical models for animal feeding behaviour. Behav. Process., 67(1), 99–109.
Abstract: We investigate models for animal feeding behaviour, with the aim of improving understanding of how animals organise their behaviour in the short term. We consider three classes of model: hidden Markov, latent Gaussian and semi-Markov. Each can predict the typical `clustered' feeding behaviour that is generally observed, however they differ in the extent to which `memory' of previous behaviour is allowed to affect future behaviour. The hidden Markov model has `lack of memory', the current behavioural state being dependent on the previous state only. The latent Gaussian model assumes feeding/non-feeding periods to occur by the thresholding of an underlying continuous variable, thereby incorporating some `short-term memory'. The semi-Markov model, by taking into account the duration of time spent in the previous state, can be said to incorporate `longer-term memory'. We fit each of these models to a dataset of cow feeding behaviour. We find the semi-Markov model (longer-term memory) to have the best fit to the data and the hidden Markov model (lack of memory) the worst. We argue that in view of effects of satiety on short-term feeding behaviour of animal species in general, biologically suitable models should allow `memory' to play a role. We conclude that our findings are equally relevant for the analysis of other types of short-term behaviour that are governed by satiety-like principles.
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Ghirlanda, S., & Vallortigara, G. (2004). The evolution of brain lateralization: a game-theoretical analysis of population structure. Proceedings of the Royal Society of London. Series B: Biological Sciences, 271(1541), 853–857.
Abstract: In recent years, it has become apparent that behavioural and brain lateralization at the population level is the rule rather than the exception among vertebrates. The study of these phenomena has so far been the province of neurology and neuropsychology. Here, we show how such research can be integrated with evolutionary biology to understand lateralization more fully. In particular, we address the fact that, within a species, left– and right–type individuals often occur in proportions different from one–half (e.g. hand use in humans). The traditional explanations offered for lateralization of brain function (that it may avoid unnecessary duplication of neural circuitry and reduce interference between functions) cannot account for this fact, because increased individual efficiency is unrelated to the alignment of lateralization at the population level. A further puzzle is that such an alignment may even be disadvantageous, as it makes individual behaviour more predictable to other organisms. Here, we show that alignment of the direction of behavioural asymmetries in a population can arise as an evolutionarily stable strategy when individual asymmetrical organisms must coordinate their behaviour with that of other asymmetrical organisms. Brain and behavioural lateralization, as we know it in humans and other vertebrates, may have evolved under basically ‘social’ selection pressures.
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Williams, J. L., Friend, T. H., Nevill, C. H., & Archer, G. (2004). The efficacy of a secondary reinforcer (clicker) during acquisition and extinction of an operant task in horses. Appl. Anim. Behav. Sci., 88(3-4), 331–341.
Abstract: “Clicker training” is a popularly promoted training method based on operant conditioning with the use of a secondary reinforcer (the clicker). While this method draws from theories of learning and is used widely, there has been little scientific investigation of its efficacy. We used 60 horses, Equus callabus, and assigned each horse to one of six reinforcement protocols. The reinforcement protocols involved combinations of reinforcers administered (primary versus secondary plus primary), schedule of reinforcement (continuous versus variable ratio), and reinforcers applied during extinction (none or secondary). There were no differences (P>=0.11) between horses which received a secondary reinforcer (click) followed by the primary reinforcer (food) and those which received only the primary reinforcer (food) in the number of trials required to train the horses to touch their noses to a plastic cone (operant response). There also were no differences (P>=0.12) between horses which received the secondary reinforcer plus primary reinforcer and those which received only the primary reinforcer in regards to the number of trials to extinction. We conclude that there is no difference in the amount of training required to learn the operant task or in the task's resistance to extinction between horses that received a secondary reinforcer followed by a primary reinforcer versus horses which received only a primary reinforcer.
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Hunt, G. R., & Gray, R. D. (2004). The crafting of hook tools by wild New Caledonian crows. Proc. Roy. Soc. Lond. B Biol. Sci., 271, S88–S90.
Abstract: The 'crafting' of tools involves (i) selection of appropriate raw material, (ii) preparatory trimming and (iii) fine, three-dimensional sculpting. Its evolution is technologically important because it allows the open-ended development of tools. New Caledonian crows manufacture an impressive range of stick and leaf tools. We previously reported that their toolkit included hooked implements made from leafy twigs, although their manufacture had never been closely observed. We describe the manufacture of 10 hooked-twig tools by an adult crow and its dependent juvenile. To make all 10 tools, the crows carried out a relatively invariant three-step sequence of complex manipulations that involved (i) the selection of raw material, (ii) trimming and (iii) a lengthy sculpting of the hook. Hooked-twig manufacture contrasts with the lack of sculpting in the making of wooden tools by other non-humans such as chimpanzees and woodpecker finches. This fine, three-stage crafting process removes another alleged difference between humans and other animals.
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Dall, S. R. X., Houston, A. I., & McNamara, J. M. (2004). The behavioural ecology of personality: consistent individual differences from an adaptive perspective. Ecol. Letters, 7, 734–739.
Abstract: Individual humans, and members of diverse other species, show consistent differences in
aggressiveness, shyness, sociability and activity. Such intraspecific differences in
behaviour have been widely assumed to be non-adaptive variation surrounding
(possibly) adaptive population-average behaviour. Nevertheless, in keeping with recent
calls to apply Darwinian reasoning to ever-finer scales of biological variation, we sketch
the fundamentals of an adaptive theory of consistent individual differences in behaviour.
Our thesis is based on the notion that such .personality differences. can be selected for if
fitness payoffs are dependent on both the frequencies with which competing strategies
are played and an individual`s behavioural history. To this end, we review existing models
that illustrate this and propose a game theoretic approach to analyzing personality
differences that is both dynamic and state-dependent. Our motivation is to provide
insights into the evolution and maintenance of an apparently common animal trait:
personality, which has far reaching ecological and evolutionary implications.
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Rietmann, T. R., Stauffacher, M., Bernasconi, P., Auer, J. A., & Weishaupt, M. A. (2004). The association between heart rate, heart rate variability, endocrine and behavioural pain measures in horses suffering from laminitis. J Vet Med A Physiol Pathol Clin Med, 51(5), 218–225.
Abstract: The objective of this study was to compare the stress response of horses suffering from laminitis after short- and long-term treatment with the intent to evaluate power spectral analysis of heart rate variability (HRV) for pain monitoring. Data were collected from 19 horses with acute or chronic exacerbating laminitis without known primary disease before and after treatment with non-steroidal anti-inflammatory drugs (NSAID). Recordings were carried out the day after admission to the equine hospital. Measurements were repeated on day 7 of the treatment. The recorded parameters included a clinical orthopaedic index (OLPI: Obel-grade plus hoof tester score), frequency of weight-shifting between contralateral limbs, mean beat-to-beat interval (R-R) duration, standard deviation of continuous R-R intervals, low- (LF) and high-frequency (HF) components of HRV, sympatho-vagal balance (LF/HF), and plasma concentration of cortisol, adrenalin and noradrenalin. The LF represents mainly sympathetic influences on the heart whereas HF is mediated by the parasympathetic tone. Weight-shifting and OLPI decreased significantly with treatment. The LF normalized units (n.u.) decreased after NSAID from 60.41 +/- 21.42 to 51.12 +/- 19.81 and was 49.33 +/- 22.64 on day 7, whereas HF n.u. increased from 35.07 +/- 20.02 to 43.14 +/- 18.30 and was 45.98 +/- 23.00 on day 7. Hormone levels showed no tendency to change with treatment. The OLPI was only correlated with LF/HF, LF and HF (R = 0.57, 0.55 and -0.54 respectively). Significant negative correlations existed between HFn.u. and weight-shifting frequency (R = -0.37), HFn.u. and adrenalin (R = -0.47), and HFn.u. and noradrenalin (R = 0.33). The LFn.u. only correlated positively with adrenalin. Cortisol levels were poorly associated with the other parameters. Determination of the sympatho-vagal influences on cardiac function may offer complementary information for reliable assessment of pain and may represent a valuable alternative method to catecholamine measurements.
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