This day started with the talk by Alex Kacelnik on choice and decision-making in starlings. This was again a very interesting talk and contained a lot of theoretical considerations about decision-making after showing a series of very cleverly designed experiments. For instance, he told us that choice may be a computation of behavioral actions with different latencies (when the choice is forced by a stimulus). These theoretical considerations were derived from modelling the experimental data. Interestingly, in their experiments, starling respond more quickly when faced with a simultaneous choice than with a sequential choice. In total, Kacelnik compared his sequential choice model with about 5-6 different choice experiments and his model fitted the data better than more complex models.
The second talk rang from home in a way as it was by Mandyam Srinivasan on honeybees (our department works largely on honeybees). After some introductory history on pattern recognition in bees, he told us about how bees an generalize certain features of patterns, such as orientation or symmatry, even up to the extent that they can learn to solve a delayed matching-to-sample test with a set of entirely new patterns, an experiment famously published in Nature. I just found that a very similar talk, together with many of the slides he showed here is posted here. He also showed us data indicating that bees can count up to about 4. Finally he showed some very intersting experiment in which it became clear how bees use the polarized light pattern on the sky for orientation.
The final talk before lunch was by Nigel Franks on House Rock Ants. These ants make decisions as to which area is best suited for a new nest. The main criterion for this choice is the size (area) of the nest. The go into potential sites, lay down scent trails and then re-visit the sites for comparison. Other contributing features are brightness and headspace. The data suggest that these ants use a weighted additive strategy for their choice. Similar to the results from Alex Kacelnik in starlings, the ant data suggest that this nest choice is done sequentially and involves mainly thresholds and timing. If the ants are forced to choose a nest quickly, they make more erros, i.e., choose a nest which is inferior to the other option, indicating a speed/accuracy trade-off. Nigel next went to the topic of teaching in ants, also famously published in Nature. In tis paper he and his student argued that the tandem runs of these ants from the old nest to the new nest constitutes all important criteria for teaching. Nigel's final section was about tracking individual ants using RFID tags glued to their tergites. He used this technique to investigate the way the ants decide between a near but bad nest and a far away but better nest. It turned out they first recruit to the worse, close nest and then switch to searching for the far away, better nest. Individual ants are able to make a decision for the better nest and break the colony consensus for the worse nest. This means that a portion of ants is continuously looking for better nests, even if a nest is being or has already been established.