No abstract

Individual infant guinea pigs were tested oncde a week during the first 4 weeks of life in a square enclosure which was separated from a smaller enclosure (confinement cage) by a wire-mesh partition. In the Experimental condition (E) the mother and siblings of the subject were present in the confinement cage during testing - while in the Control condition (C) the confinement cage was empty during testing. The young guinea pigs tested in the presence of the mother and siblings displayed a much greater level of activity (i.e. exploratory behaviour) than did those tested with the empty confinement cage. They thus appeared to use the mother and/or siblings as a base from which to explore a novel environment. Exploratory behaviour in condition E showed a significant increase between weeks I and 2 (possibly due to the waning of an initial immobility reaction), and a gradual decline over weeks 3 and 4 (believed to be due to habituation to the test enclosure). In condition C, there were no significant differences in activity between trials. The guinea pigs tested in the presence of the mother and siblings spent significantly more time near the wire partition separating the test enclosure from the confinement cage than did the control subjects - for whom the confinement cage was empty. Subjects in condition E spent significantly more time in the proximity of the mother and siblings during weeks 2-4 as compared to week I. The responsiveness of the young guinea pigs to conspecifics therefore appears to have increased over the first 2 weeks post-partum. The possible adaptive significance of the interaction between exploration and attachment behaviour was discussed.

Infant guinea pigs were "exposure-tramed" with either a rotating striped cube or a tennis ball. When they were tested fater for choice between the cube and the ball, the animals were found to spend more time near the object with which they had been "trained." A total training period of 20 min proved to be just as effective as one of 4 h. Control animals, exposed to an emp ty training pen, prefe"ed the cube.

and di. .. . crimination 1earnin!! a"i a function of hunger anu relative n?~ron,,>e frequcncy.

Five- and six-day old chicks were found to prefer a complex stimulus to a simple one, whilst 2-day old ones showed no such preference; but a red stimulus, whether simple or complex, tended to be preferred at both age levels when it was paired with a non-coloured complex stimulus. Preference for complexity may be usefully viewed in any species in the context of the behavioural development of the individual.