Abstract: In a trial of cage designs for laying hens, eggs were discovered in dust baths where access was restricted by a closed door during the normal laying period (08:00-13:00 h). Observations showed that the hens in these dust bath treatments had developed methods of opening the doors in order to lay in the baths. Three different methods of opening were observed. An average time of 34.4 min was spent attempting to open the doors before access was finally achieved. This implies a strong nesting motivation in these hens. The proportion of eggs laid in the dust baths increased (with occasional fluctuations) over a 24-week period. Door opening is likely to have initially developed in one individual in each cage through a trial and error basis, and then have been learned by cage mates through imitation. The speed and efficiency of door opening was not found to increase with experience or time.

Abstract: Abstract and Summary: Since the adaptive significance of social organization is emphasized diversely in both anti-predator behaviour and food searching of birds, measures and comparisons of observational learning capacity of various species are needed. Four different experimental situations were built up for juvenile and adult individuals of tits (Parus major, P. caeruleus, P. palustris) and thrushes (Turdus merula, T. philo-melos). The birds learn more easily from conspecifics and learn easily when they already know a previous problem solving situation. The capacity of observational learning of the adult great tits surpasses that of adult blue tits and marsh tits, and that of the adult blackbirds exceeds that of the adult songthrushes. The higher performance of the great tit and blackbird can be related to their greater hemispheric index. The differences in the learning capacity of the naive individuals of the three tit species and that of the two thrush species were not significant. It is suggested, that the higher observational learning of the great tit and blackbird is evolved through maturational processes and can be reflected by their greater adaptability. Zusammenfassung: Lernen durch Nachahmung wurde in vier verschiedenen Situationen mit jungen und alten Individuen von Meisen- (Parus major, P. caeruleus, P. palustris) und Drosselarten (Turdus merula, T. philomelos) untersucht. Die Vögel lernten besser von Artgenossen und lernten leicht, wenn sie vorher bereits eine Problemlösungssituation kannten. Die Lernfähigkeit (durch Nachahmung) alter Kohlmeisen übertraf die alter Blau- und Sumpfmeisen; die Lernfähigkeit alter Amseln übertraf die alter Singdrosseln. Die höhere Leistung der Kohlmeisen und Amseln hängt mit ihrem höheren Hemisphären-Index zusammen. Naive Individuen der Meisen- und Drosselarten zeigten keine signifikanten Unterschiede in ihrer Lernfähigkeit. Es ist anzunehmen, daß die höhere Lernfähigkeit der Kohlmeise und der Amsel im Laufe der Entwicklung durch Reifungsprozesse zustande kommt und sich in ihrer höheren Anpassungsfähig-keit widerspiegelt.

Abstract: Numerical competence is one of the aspects of animal cognition with a long history of research interest, but few results are available for the horse. In the present study, we investigated the ability of three Shetland ponies to discriminate between different quantities of geometric symbols presented on a computer screen in a matching-to-sample arrangement. In Experiment 1, the ponies had to relate two similar quantities to another, paired in contrasts (1 vs. 2, 3 vs. 4 and 4 vs. 5) of the same stimulus (dot). Specific pairs of quantities (all differing by one) of up to five different geometrical symbols were displayed in Experiment 2. In each session, both quantities (more and less) were used as sample in such a way that each of the two quantities presented in one test served as positive and as negative stimulus, respectively. The three Shetland ponies were able to discriminate between the given quantities of dots by showing more than 80 % correct responses in two consecutive sessions. Only one of the ponies distinguished different shapes of geometric symbols at a level of 4 versus 5 items. The results show that all ponies were capable of visual quantity discrimination in the present matching-to-sample design, but task solving seemed more difficult when quantities were composed of heterogeneous stimuli. The present results confirm our hypothesis that the ponies based their decision on the matching concept of sameness and were not biased by a spontaneous preference for higher quantities.

Abstract: In recent years, considerable literature has been published on cognition in horses; however, much less is known about the cognitive abilities of domestic donkey (Equus asinus). This study aimed to expand our knowledge of donkey cognition by assessing their short-term memory capacity. We employed a detour problem combined with the classic delayed-response task, which has been extensively used to compare working memory duration in a variety of different species. A two-point choice apparatus was used to investigate location recall and search behaviour for a food target, after a short delay following its disappearance. Four donkeys completed the task with a 10 sec delay, while four others were tested with a 30 sec delay. Overall, each group performed above chance level on the test, showing that subjects had successfully encoded, maintained, and retrieved the existence and location of the target despite the loss of visual contact.