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Provenza, F. D. (1996). Acquired aversions as the basis for varied diets of ruminants foraging on rangelands. J. Anim Sci., 74(8), 2010–2020.
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Meriggi, A., & Lovari, S. (1996). A Review of Wolf Predation in Southern Europe: Does the Wolf Prefer Wild Prey to Livestock? J. Appl. Ecol, 33, 1561–1571.
Abstract: 1. The recent recovery of the wolf in southern Europe has not yet removed the risk
of local extinction. Wolf populations are fragmented and often comprise fewer than
500 individuals. In North America, northern and eastern Europe, wolves feed maiiily
on wild herbivores. In southern Europe, this canid has apparently adapted to feed
also on fruit, rubbish, livestock, small and medium-size mammals.
2. The main conservation problem lies with predation o n domestic ~ingulates,w liich
leads to extensive killing of wolves. The reintroduction of wild large herbivores has
been advocated as a means of reducing attacks on livestock, but predatiori on the
latter may remain high if domestic ungulates are locally abundant.
3. Our synthesis of 15 studies, published in the last 15 years, on food habits of the
wolf in southern Europe, has shown that ungulates have been the main diet component
overall. A significant inverse correlation was found between the occurrence (%) of
wild and domestic ungulates in the diet. The presence of relatively few wild ungulate
species was necessary to reduce predation on livestock.
4. Selection of wild and domestic ungulate prey was influenced mainly by their local
abundance, but also by their accessibility. Feeding dependence on rubbish was local
and rare. In Italy, the consumption of riibbish/fruit and that of ungulates was significantly
negatively correlated. Diet breadth increased as the presence of large prey
in tlie diet decreased.
5. The simultaneous reintroduction of severa1 wild ungulate species is likely to reduce
predation on livestock and may prove to be one of the most effective conservation
measures.
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Gueron, S., Levin, S. A., & Rubenstein, D. I. (1996). The Dynamics of Herds: From Individuals to Aggregations. J. Theor. Biol., 182(1), 85–98.
Abstract: The dynamic behavior of small herds is investigated by means of simulations of two-dimensional discrete-stochastic models. An individual-based approach is used to relate collective behavior to individual decisions. In our model, the motion of an individual in a herd is assumed to be the combined result of both density-independent and density-dependent decisions, in the latter case based on the influence of surrounding neighbors; assumed decision rules are hierarchical, balancing short range repulsion against long-range attraction. The probability of fragmentation of the model herd depends on parameter values. We explore the variety and characteristics of spatial patterns that develop during migration, for herds that are homogeneous and heterogeneous regarding intrinsic walking speeds. Group integrity can be maintained even in mixed populations, but fragmentation results for these more easily than for a homogeneous herd. Observations of natural populations suggest that animals move away from individuals that intrude too closely into their environment, but are attracted to individuals at a distance. Between these extremes, there appears to be a neutral zone, within which other individuals engender no response. We explore the importance of this neutral zone, and offer evolutionary interpretations. In particular, the neutral zone, if not too large, permits the individual to remain in contact with the herd, while reducing the frequency with which acceleration or deceleration must be undertaken. This offers obvious energetic benefits.
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Hausberger, M., Le Scolan, N., Muller, C., Gautier, E., & Wolff, A. (1996). Individual behavioural characteristics in horses: predictability, endogenous and environmental factors. Journée d`Etude, 22, 113–123.
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Hama, H., Yogo, M., & Matsuyama, Y. (1996). Effects of stroking horses on both humans' and horses' heart rate responses. Jpn. Psychol. Res., 38(2), 66–73.
Abstract: The present study examined both human and horse heart rates (HRs) when humans stroked horses for 90 seconds; the subjective arousal levels of the humans were measured by the Tohoku Activation Deactivation Adjective Check List before and after stroking horses. Six male subjects with a positive attitude toward companion animals and 6 male subjects with a negative attitude were selected by their scores on the Pet Attitude Scale, and these two groups, together with a third group, of 6 subjects who were male members of the Doshisha University horse-riding club, participated in this experiment. The HRs of the human subjects during the first 10 seconds immediately after the stroking began were significantly higher than those obtained after that period, but these higher levels gradually returned to baseline levels. This tendency appears more clearly in the negative attitude group. The HRs of the horses increased during the first 20 seconds immediately after the human subjects of the NA group started stroking them, but gradually reduced as the stroking continued. The results of subjective arousal levels suggest a decrease in tension by stroking horses. These results suggest that a certain affectional interaction may exist between humans and companion animals.
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Reed, P., Skiera, F., Adams, L., & Heyes, C. M. (1996). Effects of Isolation Rearing and Mirror Exposure on Social and Asocial Discrimination Performance. Learn. Motiv., 27(2), 113–129.
Abstract: Four experiments examined the effects of rearing in isolation on rats performance on discrimination-based and social learning tasks. After demonstrating that the rearing procedures produced similar results in an open field task to those previously established (Experiment 1), rats were subjected to two discrimination tasks: an instrumental occasion setting procedure (Experiment 3) and a nonspatial win-stay/lose-shift versus win-shift/lose-stay procedure (Experiment 4). Deficits in acquisition of the necessary discriminations were noted in the rats raised in isolation, but there were no differences between isolation-reared and socially reared subjects in response acquisition per se. In Experiment 2, rats were presented with an observational learning task using the bidirectional control procedure. Socially reared rats had a tendency to imitate the behavior they had observed, but rats raised in isolation performed the opposite behavior to that observed, indicating a failure to use a conspecific as a reference point in the task. The presence of a mirror during rearing in isolation was also investigated, but was found to have little effect in attenuating the above deficits in behavior.
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Reboreda, J. C., Clayton, N. S., & Kacelnik, A. (1996). Species and sex differences in hippocampus size in parasitic and non-parasitic cowbirds. Neuroreport, 7(2), 505–508.
Abstract: To test the hypothesis that selection for spatial abilities which require birds to locate and to return accurately to host nests has produced an enlarged hippocampus in brood parasites, three species of cowbird were compared. In shiny cowbirds, females search for host nests without the assistance of the male; in screaming cowbirds, males and females inspect hosts' nests together; in bay-winged cowbirds, neither sex searches because this species is not a brood parasite. As predicted, the two parasitic species had a relatively larger hippocampus than the non-parasitic species. There were no sex differences in relative hippocampus size in screaming or bay-winged cowbirds, but female shiny cowbirds had a larger hippocampus than the male.
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Sekuler, A. B., Lee, J. A., & Shettleworth, S. J. (1996). Pigeons do not complete partly occluded figures. Perception, 25(9), 1109–1120.
Abstract: One of the most common obstacles to object perception is the fact that objects often occlude parts of themselves and parts of other objects. Perceptual completion has been studied extensively in humans, and researchers have shown that humans do complete partly occluded objects. In an effort to understand more about the mechanisms underlying completion, recent research has extended the study of perceptual completion to other mammalian species. Monkeys and mice also seem to complete two-dimensional representations of partly occluded objects. The present study addresses the question of whether this capacity generalizes to a nonmammalian species, the pigeon (Columba livia). The results point to a limit of the generalizability of perceptual completion: pigeons do not complete partly occluded figures.
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Lebelt, D., Schönreiter, S., & Zanella, A. J. (1996). Salivary cortisol in stallions: the relationship with plasma levels, daytime profile and changes in response to semen collection. Pferdeheilkunde, 14(4), 411–414.
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Phillips, K. (1996). Natural conceptual behavior in squirrel monkeys (saimiri sciureus): An experimental investigation. Primates, 37(3), 327–332.
Abstract: Abstract Natural conceptual discriminations have been tested in many different species, including pigeons and a variety of non-human primates. The ability of four male squirrel monkeys (Saimiri sciureus) to learn and use the natural concept “squirrel monkey” was investigated in this study. After a training phase, subjects were presented with novel stimuli in transfer and test trials. All subjects performed at a rate significantly above chance on the first test trial (p<.001), indicating that squirrel monkeys can utilize natural concepts in the laboratory.
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