Skov-Rackette, S. I., Miller, N. Y., & Shettleworth, S. J. (2006). What-where-when memory in pigeons. J Exp Psychol Anim Behav Process, 32(4), 345–358.
Abstract: The authors report a novel approach to testing episodic-like memory for single events. Pigeons were trained in separate sessions to match the identity of a sample on a touch screen, to match its location, and to report on the length of the retention interval. When these 3 tasks were mixed randomly within sessions, birds were more than 80% correct on each task. However, performance on 2 different tests in succession after each sample was not consistent with an integrated memory for sample location, time, and identity. Experiment 2 tested binding of location and identity memories in 2 different ways. The results were again consistent with independent feature memories. Implications for tests of episodic-like memory are discussed.
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Gibson, B. M., & Shettleworth, S. J. (2003). Competition among spatial cues in a naturalistic food-carrying task. Learn Behav, 31(2), 143–159.
Abstract: Rats collected nuts from a container in a large arena in four experiments testing how learning about a beacon or cue at a goal interacts with learning about other spatial cues (place learning). Place learning was quick, with little evidence of competition from the beacon (Experiments 1 and 2). Rats trained to approach a beacon regardless of its location were subsequently impaired when the well-learned beacon was removed and other spatial cues identified the location of the goal (Experiment 3). The competition between beacon and place cues reflected learned irrelevance for place cues (Experiment 4). The findings differ from those of some studies of associative interactions between cue and place learning in other paradigms.
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Jones, J. E., Antoniadis, E., Shettleworth, S. J., & Kamil, A. C. (2002). A comparative study of geometric rule learning by nutcrackers (Nucifraga columbiana), pigeons (Columba livia), and jackdaws (Corvus monedula). J Comp Psychol, 116(4), 350–356.
Abstract: Three avian species, a seed-caching corvid (Clark's nutcrackers; Nucifraga columbiana), a non-seed-caching corvid (jackdaws; Corvus monedula), and a non-seed-caching columbid (pigeons; Columba livia), were tested for ability to learn to find a goal halfway between 2 landmarks when distance between the landmarks varied during training. All 3 species learned, but jackdaws took much longer than either pigeons or nutcrackers. The nutcrackers searched more accurately than either pigeons or jackdaws. Both nutcrackers and pigeons showed good transfer to novel landmark arrays in which interlandmark distances were novel, but inconclusive results were obtained from jackdaws. Species differences in this spatial task appear quantitative rather than qualitative and are associated with differences in natural history rather than phylogeny.
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Shettleworth, S. J., & Westwood, R. P. (2002). Divided attention, memory, and spatial discrimination in food-storing and nonstoring birds, black-capped chickadees (Poecile atricapilla) and dark-eyed juncos (Junco hyemalis). J Exp Psychol Anim Behav Process, 28(3), 227–241.
Abstract: Food-storing birds, black-capped chickadees (Poecile atricapilla), and nonstoring birds, dark-eyed juncos (Junco hyemalis), matched color or location on a touch screen. Both species showed a divided attention effect for color but not for location (Experiment 1). Chickadees performed better on location than on color with retention intervals up to 40 s, but juncos did not (Experiment 2). Increasing sample-distractor distance improved performance similarly in both species. Multidimensional scaling revealed that both use a Euclidean metric of spatial similarity (Experiment 3). When choosing between the location and color of a remembered item, food storers choose location more than do nonstorers. These results explain this effect by differences in memory for location relative to color, not division of attention or spatial discrimination ability.
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Gibson, B. M., Shettleworth, S. J., & McDonald, R. J. (2001). Finding a goal on dry land and in the water: differential effects of disorientation on spatial learning. Behav. Brain. Res., 123(1), 103–111.
Abstract: Two previous studies, Martin et al. (J. Exp. Psychol. Anim. Behav. Process. 23 (1997) 183) and Dudchenko et al. (J. Exp. Psychol. Anim. Behav. Process. 23 (1997) 194), report that, compared to non-disoriented controls, rats disoriented before testing were disrupted in their ability to learn the location of a goal on a dry radial-arm maze task, but that both groups learned at the same rate in the Morris water maze. However, the radial-arm maze task was much more difficult than the water maze. In the current set of experiments, we examined the performance of control and disoriented rats on more comparable dry land and water maze tasks. Compared to non-disoriented rats, rats that were disoriented before testing were significantly impaired in locating a goal in a circular dry arena, but not a water tank. The results constrain theoretical explanations for the differential effects of disorientation on different spatial tasks.
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Clutton-Brock, T. H., Greenwood, P. J., & Powell, R. P. (1976). Ranks and relationships in Highland ponies and Highland Cows. Z. Tierpsychol., 41(2), 202–216.
Abstract: Recent studies of primates have questioned the importance of dominance hierarchies in groups living under natural conditions. In a herd of Highland ponies and one of Highland cattle grazing under free-range conditions on the Isle of Rhum (Inner Hebrides) well defined hierarchies were present. The provision of food produced a marked increase in the frequency of agonistic interactions but had no effect on the rank systems of the two herds. While rank was clearly important in affecting the distribution of agonistic interactions, it was poorly related to behaviour in non-agonistic situations.
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Hamilton, W. D. (1971). Geometry for the selfish herd. J. Theor. Biol., 31(2), 295–311.
Abstract: This paper presents an antithesis to the view that gregarious behaviour is evolved through benefits to the population or species. Following Galton (1871) and Williams (1964) gregarious behaviour is considered as a form of cover-seeking in which each animal tries to reduce its chance of being caught by a predator.
It is easy to see how pruning of marginal individuals can maintain centripetal instincts in already gregarious species; some evidence that marginal pruning actually occurs is summarized. Besides this, simply defined models are used to show that even in non-gregarious species selection is likely to favour individuals who stay close to others.
Although not universal or unipotent, cover-seeking is a widespread and important element in animal aggregation, as the literature shows. Neglect of the idea has probably followed from a general disbelief that evolution can be dysgenic for a species. Nevertheless, selection theory provides no support for such disbelief in the case of species with outbreeding or unsubdivided populations.
The model for two dimensions involves a complex problem in geometrical probability which has relevance also in metallurgy and communication science. Some empirical data on this, gathered from random number plots, is presented as of possible heuristic value.
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Gibbs, S. E. B., Lea, S. E. G., & Jacobs, L. F. (2007). Flexible use of spatial cues in the southern flying squirrel (Glaucomys volans). Anim. Cogn., 10(2), 203–209.
Abstract: Insects, birds, and mammals have been shown capable of encoding spatial information in memory using multiple strategies or frames of reference simultaneously. These strategies include orientation to a goal-specific cue or beacon, to the position of the goal in an array of local landmarks, or to its position in the array of distant landmarks, also known as the global frame of reference. From previous experiments, it appears that birds and mammals that scatter hoard rely primarily on a global frame of reference, but this generalization depends on evidence from only a few species. Here we examined spatial memory in a previously unstudied scatter hoarder, the southern flying squirrel. We dissociated the relative weighting of three potential spatial strategies (beacon, global, or relative array strategy) with three probe tests: transposition of beacon and the rotation or the expansion of the array. The squirrels' choices were consistent with a spatial averaging strategy, where they chose the location dictated by at least two of the three strategies, rather than using a single preferred frame of reference. This adaptive and flexible heuristic has not been previously described in animal orientation studies, yet it may be a common solution to the universal problem of encoding and recalling spatial locations in an ephemeral physical landscape.
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Fiset, S., & Leblanc, V. (2007). Invisible displacement understanding in domestic dogs (Canis familiaris): the role of visual cues in search behavior. Anim. Cogn., 10(2), 211–224.
Abstract: Recently, (Collier-Baker E, Davis JM, Suddendorf T (2004) J Comp Psychol 118:421-433) suggested that domestic dogs do not understand invisible displacements. In the present study, we further investigated the hypothesis that the search behavior of domestic dogs in invisible displacements is guided by various visual cues inherent to the task rather than by mental representation of an object's past trajectory. Specifically, we examined the role of the experimenter as a function of the final position of the displacement device in the search behavior of domestic dogs. Visible and invisible displacement problems were administered to dogs (N = 11) under two conditions. In the Visible-experimenter condition, the experimenter was visible whereas in the Concealed-experimenter condition, the experimenter was visibly occluded behind a large rigid barrier. Our data supported the conclusion that dogs do not understand invisible displacements but primarily search as a function of the final position of the displacement device and, to a lesser extent, the position of the experimenter.
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Chiesa, A. D., Pecchia, T., Tommasi, L., & Vallortigara, G. (2006). Multiple landmarks, the encoding of environmental geometry and the spatial logics of a dual brain. Anim. Cogn., 9(4), 281–293.
Abstract: A series of place learning experiments was carried out in young chicks (Gallus gallus) in order to investigate how the geometry of a landmark array and that of a walled enclosure compete when disoriented animals could rely on both of them to re-orient towards the centre of the enclosure. A square-shaped array (four wooden sticks) was placed in the middle of a square-shaped enclosure, the two structures being concentric. Chicks were trained to ground-scratch to search for food hidden in the centre of the enclosure (and the array). To check for effects of array degradation, one, two, three or all landmarks were removed during test trials. Chicks concentrated their searching activity in the central area of the enclosure, but their accuracy was inversely contingent on the number of landmarks removed; moreover, the landmarks still present within the enclosure appeared to influence the shape of the searching patterns. The reduction in the number of landmarks affected the searching strategy of chicks, suggesting that they had focussed mainly on local cues when landmarks were present within the enclosure. When all the landmarks were removed, chicks searched over a larger area, suggesting an absolute encoding of distances from the local cues and less reliance on the relationships provided by the geometry of the enclosure. Under conditions of monocular vision, chicks tended to rely on different strategies to localize the centre on the basis of the eye (and thus the hemisphere) in use, the left hemisphere attending to details of the environment and the right hemisphere attending to the global shape.
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