Abstract: Sixteen horses were used to determine if number of trials given per training session (5, 10, 15 or 20) affected learning performance in an avoidance conditioning task. The horse had to move from one side of a test pen to the other during an auditory cue presentation to avoid aversive stimulation. A pen 8 mx3.6 m, divided into two equal sections by a 13-cm diameter plastic pipe lying on the ground, was used as the test pen. Painted plywood panels were fastened to the fence in half the pen to help horses distinguish visually between the two parts. A 10-s auditory cue was used as a signal for horses to move from one side of the test pen to the other. A 20-s intertrial interval was used. Training sessions were conducted every third day. Each trial was recorded as an avoidance (the horse completed the task during auditory cue presentation and avoided aversive stimulus) or an error (the horse received aversive stimulus). After completing ten consecutive avoidances (criterion), the horse was removed from the study. Numbers of training sessions, trials, avoidances and errors until reaching criterion were recorded for each horse. Horses varied greatly within these variables with ranges of 3-18 sessions, 37-121 trials, 20-68 avoidances and 17-53 errors to criterion. No differences were detected (P>0.05) in the number of conditioning trials per training session (treatment) for the mean number of trials, avoidances or errors to criterion. Number of training sessions to criterion differed (P<0.01) among treatments, indicating that an optimum number of learning trials per training session might exist. Mean sessions to criterion for horses receiving 5, 10, 15 and 20 trials per session were 15.1+/-1.3, 5.8+/-1.1, 5.3+/-1.1 and 4.6+/-1.1, respectively. Regression analysis indicated that 16.2 trials per training session would minimize number of sessions to criterion. Although it is widely assumed that learning efficiency in horses is decreased when intense activity is concentrated into a small number of sessions, these results indicate that moderate repetition of training activities is needed for efficient learning.

Abstract: Four experiments were designed to find evidence of observational learning in cattle. The experiments were run on ten experimental heifers, each observing a demonstrator mate performing a task, and on ten control heifers, each observing a non-demonstrator mate. The mates and observers were separated by wire netting in Experiments 1-3, but were in the same room in Experiment 4. The task to be learned was to push a panel to get food into a box. All naive animals were able to observe while their mate performed the task. The observers in Experiments 1 and 4 were Salers heifers that had no prior experience of the testing room; those in Experiment 2 were Salers heifers that were accustomed to the room; those in Experiment 3 were Aubrac or Limousin heifers that had already eaten in the room.
The behaviour of the observers was influenced by their mates: activity at or near the boxes was enhanced by the presence of demonstrators in Experiment 2 (box contacts: 38.0 +/- 16.2 vs. 22.1 +/- 11.9 for experimental and control heifers, respectively; P<0.05), while activity in other parts of the room in Experiment 3 was enhanced when non-demonstrator mates were present (wall sniffing: 5.4 +/- 13.9 vs. 13.9 +/- 13.7; P<0.05). Overall, 26 experimental heifers vs. 19 controls learned the task (P>0.05). The time spent eating was longer when the observer only had visual contact with a demonstrator (Experiment 1: 15.9 +/- 1.6 vs. 11.6 +/- 1.8 min), but was lower when physical contacts with the demonstrator were possible (Experiment 4: 4.6 +/- 8.8 vs. 5.4 +/- 2.2 min; P<0.05).
Ten out of the 11 Limousin heifers learned the task, compared with only three out of the nine Aubrac heifers (P<0.05). The latter spent more time near the door and sniffed the walls more often than the former (2.0 +/- 1.9 vs. 0.4 +/- 0.6 min, P<0.05, and 18.1 +/- 13.4 vs. 2.7 +/- 6.5 min, P<0.01), as though they were trying to flee the situation.
When animals observed a demonstrator, their attention was drawn to stimuli involved in the task but acquisition of knowledge was not greatly improved.

Abstract: Gagnon and Dor (1992) showed that domestic dogs are able to solve a Piagetian object permanence
task called the invisible displacement problem. A toy is hidden in a container which is
moved behind a screen where the toy is removed and left. Dogs make more errors in these problems
than they do in visible displacement tests, in which the object is hidden directly behind
the target screen. In Experiment 1, we examinedcomponents ofthe standard procedure of invisible
displacements that may make encoding or retention of the hiding location more difficult than
it is in visible displacements. In Experiment 2, we compared dogs performances in visible and
invisible displacement problems when delays of 0, 10, and 20 sec were introduced between the
objects final disappearance and the subjects release. The results revealed that dogs poorer performance
in invisible displacement tests is related to the complex sequence of events that have
to be encoded or remembered as well as to a difficulty in representing the position change that
is signaled, but not directly perceived.

Abstract: There is evidence that female three-spined sticklebacks, Gasterosteus aculeatus L., prefer to mate with males whose nests contain eggs rather than with males with empty nests. While there is consensus on this point, a dispute exists about whether this preference should be attributed to a direct effect of the eggs on the female's entering the nest or, alternatively, to a positive impact of the eggs on the courtship behaviour and breeding coloration of the male. In the field experiment reported here females strongly preferred nests with eggs over empty nests. Additionally, females were less likely to enter risky nests with eggs: nests that contained fewer eggs than one average clutch or more eggs than the average nest content of parental males in this population. However, in the field possible differences in male attractiveness were not controlled for. In supplementary laboratory experiments the effect on female choice of possible changes in male attractiveness (intensified courtship and coloration) as a result of the presence of eggs in the nest was tested. Other differences in male attractiveness as a result of differences in male quality (body size, breeding coloration before the test, territory quality and size) were controlled for. When females had no access to the nests, they showed no preference for males with eggs in their nests in simultaneous choice tests. These results, together with the earlier published data, make it likely that the preference of females for nests with eggs is partly a direct consequence of the eggs themselves. So female sticklebacks are influenced by the mate choice behaviour of other females, but remain selective as to the actual nest content.

Abstract: Abstract. The relation between memory for travel time and foraging decisions was studied experimentally. The temporal properties of two environments with patchily distributed food were simulated in the laboratory using pigeons, Columba livia, as subjects. The two environments differed in mean travel time, while the coefficient of variation of travel time and the decelerated function relating cumulative food gain to time in the patch were held constant within and between environments. Each environment contained a uniform mixture of five travel times experienced in a random order. Two of the five travel times were common in both environments. Effects of travel time were studied by comparing prey collected per patch visit (PPV) after various travel times within each environment, and by comparing patch exploitation after equal travel times between environments. Within the environment with long mean travel time (LMT) PPV was positively correlated with the last and the penultimate travel times but not with travel times before that. The increase in PPV per second of last travel time was six times greater than the increase per second of penultimate travel time, implying very steep memory discounting. In the environment with short mean travel time (SMT), there was no correlation between PPV and previous travel times. However, comparisons between environments of visits following travel times common to both environments (thus removing the effect of the last travel time) showed that substantially more prey were taken after equal travel times in the LMT than in the SMT environment. This difference cannot be accounted for by the within-environment effect of penultimate travel time, implying that there is a different, less steeply devalued, effect of the mixture of travel times. A model of information processing based on combining Scalar Expectancy Theory with the predictions of rate maximization under the Marginal Value Theorem is presented. The model can approximate the results obtained in this and previous experiments and provides a framework for further analysis of memory mechanisms of foraging behaviour.