Abstract: A wealth of data demonstrating that monkeys and apes represent number have been interpreted as suggesting that sensitivity to number emerged early in primate evolution, if not before. Here we examine the numerical capacities of the mongoose lemur (Eulemur mongoz), a member of the prosimian suborder of primates that split from the common ancestor of monkeys, apes and humans approximately 47-54 million years ago. Subjects observed as an experimenter sequentially placed grapes into an opaque bucket. On half of the trials the experimenter placed a subset of the grapes into a false bottom such that they were inaccessible to the lemur. The critical question was whether lemurs would spend more time searching the bucket when food should have remained in the bucket, compared to when they had retrieved all of the food. We found that the amount of time lemurs spent searching was indicative of whether grapes should have remained in the bucket, and furthermore that lemur search time reliably differentiated numerosities that differed by a 1:2 ratio, but not those that differed by a 2:3 or 3:4 ratio. Finally, two control conditions determined that lemurs represented the number of food items, and neither the odor of the grapes, nor the amount of grape (e.g., area) in the bucket. These results suggest that mongoose lemurs have numerical representations that are modulated by Weber's Law.

Abstract: Eine tiergerechte, physiologisch und anatomisch auf die Bedürfnisse der Pferde ausgerichtete
Raufutterversorgung sollte die Kaubedürfnisse und die Beschäftigungszeiten von Pferden
ausreichend berücksichtigen. Daher – und auch aufgrund des bestehenden Kostendrucks bei
Raufutter – steigt das Interesse an Raufutterraufen, durch die möglicherweise die Futteraufnahmezeiten
verlängert sowie Futterverluste minimiert werden können.
Die vorliegende Untersuchung vergleicht das Fressverhalten und die Körperhaltung von acht
Pferden beim Einsatz von drei unterschiedlichen Futterraufen mit der Bodenfütterung in Einzelboxenhaltung.
Die Ergebnisse dieser Studie lassen den Schluss zu, dass der Einsatz von
Raufutterraufen die Futteraufnahmezeiten verlängert und somit längere Beschäftigungszeiten
für die Futteraufnahme gewährleistet werden. Außerdem konnte festgestellt werden, dass die
Pferde das Raufutter bei einer der drei untersuchten Raufen überwiegend mit natürlicher Kopf-
Hals-Haltung aufnahmen.
[Regarding the species horse, an appropriate supply of roughage should take into account the
need to chew as well as the need for occupation. In this context, and due to the current cost
pressure for hay, the interest in roughage racks increases. It is assumed that roughage racks
could help to extend the feeding time and reduce food losses.
The present study places the emphasis on the observation of the feeding behaviour of eight
horses in single horse boxes. Three different roughage racks are compared to traditional feeding
on the floor. On the basis of the results it may be concluded that the use of roughage racks
extends the feeding time and thus ensures longer occupation. In one of the three roughage
racks investigated the horses mainly eat in a natural posture of their head and neck.]

Abstract: This article explores the maternal role in the acquisition of tool-use behaviours by infant chimpanzees ( Pan troglodytes). A honey-fishing task, simulating ant/termite fishing found in the wild, was introduced to three dyads of experienced mother and naive infant chimpanzees. Four fishing sites and eight sets of 20 objects to be used as tools, not all appropriate, were available. Two of the mothers constantly performed the task, using primarily two kinds of tools; the three infants observed them. The infants, regardless of the amount of time spent observing, successfully performed the task around the age of 20-22 months, which is earlier than has been recorded in the wild. Two of the infants used the same types of tools that the adults predominantly used, suggesting that tool selectivity is transmitted. The results also show that adults are tolerant of infants, even if unrelated; infants were sometimes permitted to lick the tools, or were given the tools, usually without honey, as well as permitted to observe the adult performances closely.

Abstract: The present work is part of a decade-long study on the spontaneous use of stones for cracking hard-shelled nuts by a semi-free-ranging group of brown capuchin monkeys (Cebus apella). Nutcracking events are frequently watched by other individuals--usually younger, less proficient, and that are well tolerated to the point of some scrounging being allowed by the nutcracker. Here we report findings showing that the choice of observational targets is an active, non-random process, and that observers seem to have some understanding of the relative proficiency of their group mates, preferentially watching the more skilled nutcrackers, which enhances not only scrounging payoffs, but also social learning opportunities.

Abstract: Male mammals typically outperform their conspecific females on spatial tasks. A sex difference in cues used to solve the task could underlie this performance difference as spatial ability is reliant on appropriate cue use. Although comparative studies of memory in food-storing and non-storing birds have examined species differences in cue preference, few studies have investigated differences in cue use within a species. In this study, we used a one-trial associative food-finding task to test for sex differences in cue use in the great tit, Parus major. Birds were trained to locate a food reward hidden in a well covered by a coloured cloth. To determine whether the colour of the cloth or the location of the well was learned during training, the birds were presented with three wells in the test phase: one in the original location, but covered by a cloth of a novel colour, a second in a new location covered with the original cloth and a third in a new location covered by a differently coloured cloth. Both sexes preferentially visited the well in the training location rather than either alternative. As great tits prefer colour cues over spatial cues in one-trial associative conditioning tasks, cue preference appears to be related to the task type rather than being species dependent.