Abstract: A review of the past 50 years of literature on socially guided behaviour addresses two questions: (1) whether socially guided behaviour, which has traditionally been considered characteristic of vertebrates, is also found among non-insect invertebrates, and (2) to see whether our classification of socially guided behaviours in invertebrates matches, and thereby supports, A. Whiten and R. Ham's classification of vertebrate behaviours into two broad categories, social learning and social influence. We systematically reviewed the literature on socially guided behaviour in non-insect invertebrates to determine if social behaviours exist. Once this was established, we characterised our findings using 13 behavioural phenomena that are considered to be descriptive of socially guided behaviour. Using a multivariate technique, we then analysed the data to determine if our characterisation scheme produced a similar distribution to that presented by A. Whiten and R. Ham. Our results indicate that socially guided behaviours are present in invertebrates, and invertebrates can be placed into the previously established framework on vertebrate social behaviour. Further, our analysis reveals a prominent separation between representations of the social influence and social learning categories, thereby supporting the previously published framework on socially guided behaviour.

Abstract: Two series of experiments investigated factors affecting utterance of food calls in the domestic hen, Gallus domesticus. The first series of experiments tested the effect of food preference and the hen’s internal state on the utterance of food calls. Different food types were presented first singly and then in a choice test to 20 hens, first when hens were laying, and then when they were maternal. The second series of experiments tested the effect of hunger level on the utterance of food calls in laying hens, and maternal hens with or without chicks. These two series of experiments showed that laying hens and maternal hens showed a similar marked preference for certain types of food, but laying hens very rarely emitted food calls, in contrast to maternal hens. This shows the effect of the bird’s psychophysiological state on her tendency to emit food calls. The more a maternal hen preferred a food type, the more food calls she emitted. This was observed from the beginning of a test in single-food tests as well as in choice tests. Hunger level positively affected food-call production under certain feeding conditions in maternal hens, but not in laying hens. When maternal hens were tested in the absence of their chicks, utterance of food calls was more sustained than in the presence of chicks.

Abstract: The purpose of the present study is to examine the applicability of a computer-generated, virtual animal to study animal cognition. Pigeons were trained to discriminate between movies of a real pigeon and a rat. Then, they were tested with movies of the computer-generated (CG) pigeon. Subjects showed generalization to the CG pigeon, however, they also responded to modified versions in which the CG pigeon was showing impossible movement, namely hopping and walking without its head bobbing. Hence, the pigeons did not attend to these particular details of the display. When they were trained to discriminate between the normal and the modified version of the CG pigeon, they were able to learn the discrimination. The results of an additional partial occlusion test suggest that the subjects used head movement as a cue for the usual vs. unusual CG pigeon discrimination.

Abstract: Three experiments explored the baboon's discrimination of visual displays that comprised 2 to 24 black-and-white computer icons; the displayed icons were either the same as ( same) or different from one another ( different). The baboons' discrimination of same from different displays was a positive function of the number of icons. When the number of icons was decreased to 2 or 4, the baboons responded indiscriminately to the same and different displays, exhibiting strong position preferences. These results are both similar to and different from those of pigeons that were trained and tested under comparable conditions.

Abstract: We examined the ability of domestic dogs to choose the larger versus smaller quantity of food in two experiments. In experiment 1, we investigated the ability of 29 dogs (results from 18 dogs were used in the data analysis) to discriminate between two quantities of food presented in eight different combinations. Choices were simultaneously presented and visually available at the time of choice. Overall, subjects chose the larger quantity more often than the smaller quantity, but they found numerically close comparisons more difficult. In experiment 2, we tested two dogs from experiment 1 under three conditions. In condition 1, we used similar methods from experiment 1 and tested the dogs multiple times on the eight combinations from experiment 1 plus one additional combination. In conditions 2 and 3, the food was visually unavailable to the subjects at the time of choice, but in condition 2, food choices were viewed simultaneously before being made visually unavailable, and in condition 3, they were viewed successively. In these last two conditions, and especially in condition 3, the dogs had to keep track of quantities mentally in order to choose optimally. Subjects still chose the larger quantity more often than the smaller quantity when the food was not simultaneously visible at the time of choice. Olfactory cues and inadvertent cuing by the experimenter were excluded as mechanisms for choosing larger quantities. The results suggest that, like apes tested on similar tasks, some dogs can form internal representations and make mental comparisons of quantity.