18 research outputs found
What animals do not do or fail to find: A novel observational approach for studying cognition in the wild
Mandrills learn two-day time intervals in a naturalistic foraging situation
Primates display high efficiency in finding food in complex environments. Knowledge that many plant species produce fruit simultaneously, can help primates to anticipate fruit finding at the start of fruiting seasons. Knowledge of elapsed time can help primates decide when to revisit food trees to find ripened fruit and to return before competitors find these fruits. To investigate whether mandrills are able to learn time intervals of recurring food, we recorded the foraging choices of captive mandrills in a group setting. We used a procedure with renewable food rewards that could be searched for: carrots and grapes, hidden underground in specific places with different renewal intervals (2 and 5 days, respectively). We monitored the first choice of location for individuals, if other individuals had not already searched at the same location, to exclude possible effects of individuals following others rather than relying on memory. Throughout the study, the mandrills became increasingly likely to first search at carrot locations on carrot days, while the probability of them searching at carrot locations decreased on days without carrot. Due to model instability, our results were inconclusive about an effect of grape days on the choice of the mandrills. Cues provided by conspecifics indicating the availability of simultaneously emerging food rewards did not affect the choice of the mandrills. We conclude that mandrills can take into account elapsed time in a foraging context. Thereby, this study indicates how mandrills can use temporal cognitive abilities to overcome temporal challenges of food-finding in a group setting.</p
Travel linearity and speed of human foragers and chimpanzees during their daily search for food in tropical rainforests
Sooty mangabeys use auditory cues to scavenge on nuts cracked by chimpanzees and red river hogs:An investigation of inter-specific interactions around tropical nut trees
Chimpanzees (Pan troglodytes) navigate to find hidden fruit in a virtual environment
Action Contro
De wortels en vruchten van ons primatenbrein
Oratie uitgesproken door Prof.dr. Karline R. L. Janmaat bij de aanvaarding van het ambt van hoogleraar ‘Cognitieve gedragsecologie’, bijzondere leerstoel vanwege de Stichting tot Instandhouding van de Diergaarde van het Koninklijk Zoölogisch Genootschap Natura Artis Magistra aan de Universiteit Leiden op vrijdag 10 juni 2022</p